ORCID Profile
0000-0001-5971-273X
Current Organisation
Bond University
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Developmental Psychology and Ageing | Neurocognitive Patterns and Neural Networks | Psychology | Population, Ecological and Evolutionary Genetics | Genetics
ANZSRC Socio-Economic Objective (SEO)
Expanding Knowledge in Psychology and Cognitive Sciences | Health Related to Ageing | Nervous System and Disorders | Ageing and Older People |
Related Links
Publications
Not all drugs are created equal: impaired future thinking in opiate, but not alcohol, users
Publisher: Springer Science and Business Media LLC
Date: 11-08-2018
DOI: 10.1007/S00221-018-5355-7
Abstract: Episodic future thinking refers to the ability to travel forward in time to pre-experience an event. Although future thinking has been intimately linked with self and identity, to our knowledge, no prior research has compared episodic future thinking in populations with different substance use disorders. This study investigates whether there are differences in episodic future thinking between these alcohol and opiate users. The study recruited participants who were on the opiate substitution program (n = 31) and in iduals who had been diagnosed with alcohol dependence (n = 21) from the Royal Prince Alfred Hospital Drug and Health Services. Healthy controls (n = 23) were recruited via Royal Prince Alfred Hospital databases and the general community. Past and future thinking was measured using four cue words. After each cue word, participants rated their phenomenological experience (e.g. emotion, reliving experience). Results indicated that alcohol-dependent in iduals performed significantly higher in episodic future thinking compared to opiate users. These findings indicate that not all substance use disorder groups share similar episodic thinking capabilities. Our results suggest that the self-projection component of rehabilitation programs may have to be tailored to the different episodic construction abilities found in substance use disorder groups.
Depression Reduces Accuracy While Parkinsonism Slows Response Time for Processing Positive Feedback in Patients with Parkinson’s Disease with Comorbid Major Depressive Disorder Tested on a Probabilist
Publisher: Frontiers Media SA
Date: 12-06-2017
Freezing of gait in Parkinson's disease is associated with functional decoupling between the cognitive control network and the basal ganglia
Publisher: Oxford University Press (OUP)
Date: 18-10-2013
DOI: 10.1093/BRAIN/AWT272
Abstract: Recent neuroimaging evidence has led to the proposal that freezing of gait in Parkinson's disease is due to dysfunctional interactions between frontoparietal cortical regions and subcortical structures, such as the striatum. However, to date, no study has employed task-based functional connectivity analyses to explore this hypothesis. In this study, we used a data-driven multivariate approach to explore the impaired communication between distributed neuronal networks in 10 patients with Parkinson's disease and freezing of gait, and 10 matched patients with no clinical history of freezing behaviour. Patients performed a virtual reality gait task on two separate occasions (once ON and once OFF their regular dopaminergic medication) while functional magnetic resonance imaging data were collected. Group-level independent component analysis was used to extract the subject-specific time courses associated with five well-known neuronal networks: the motor network, the right- and left cognitive control networks, the ventral attention network and the basal ganglia network. We subsequently analysed both the activation and connectivity of these neuronal networks between the two groups with respect to dopaminergic state and cognitive load while performing the virtual reality gait task. During task performance, all patients used the left cognitive control network and the ventral attention network and in addition, showed increased connectivity between the bilateral cognitive control networks. However, patients with freezing demonstrated functional decoupling between the basal ganglia network and the cognitive control network in each hemisphere. This decoupling was also associated with paroxysmal motor arrests. These results support the hypothesis that freezing behaviour in Parkinson's disease is because of impaired communication between complimentary yet competing neural networks.
Examining patience as a psycho-religious construct in Iranian patients with cardiovascular diseases: a pilot study
Publisher: Informa UK Limited
Date: 09-08-2017
Effect of Best Possible Self Intervention on Situational Motivation and Commitment in Academic Context
Publisher: Elsevier BV
Date: 02-2020
A pilot study of escape, avoidance, and approach behaviors in treated alcohol-dependent males
Publisher: Informa UK Limited
Date: 25-04-2019
DOI: 10.1080/13803395.2019.1595530
Abstract: Alcohol-dependent in iduals are often reported to use behavioral strategies both to escape from and avoid negative affective states, and also to approach positive affective states. However, there has been little examination of how these in iduals acquire and express these types of behaviors. In this study, male adults meeting the International Classification of Diseases-10th Revision (ICD-10) criteria for alcohol dependence recruited from an outpatient treatment clinic and healthy male controls were given a computer-based task to assess learning and performance of escape, avoidance, and approach behaviors. In this task, participants control a spaceship and can either gain points by shooting an enemy spaceship or hide in safe areas to escape or avoid on-screen aversive events. We found that patients with alcohol dependence exhibited greater escape and approach behaviors, tended to show greater avoidance behavior, and achieved higher total score on the computer task than healthy controls. This is the first demonstration of such behavioral differences in this population, supporting the overactivation of both positive and negative reinforcement systems in alcohol dependence, and suggesting that such behavioral biases are not limited to alcohol-related cues. The contribution of this work to behavioral assessment and therapeutic approaches, as well as possible future directions, are discussed.
Reward and punishment-based compound cue learning and generalization in opiate dependency
Publisher: Springer Science and Business Media LLC
Date: 27-07-2017
DOI: 10.1007/S00221-017-5046-9
Abstract: Substance dependence is thought to be mediated by abnormalities in cognitive abilities, but how this impacts decision-making remains unclear. This study aimed to test whether people who are opiate dependent differed from never-dependent controls in learning from reward and punishment or in the generalization of learning to novel conditions. Participants with opiate dependency consisted of 21 people who were outpatients in a methadone maintenance program the control group consisted of 21 healthy participants with no histories of substance abuse. Subjects completed a computer-based task that involved two phases: the training phase involved participants being presented with compound stimulus (a shape and color) in each trial, with the goal of learning which compounds to 'pick' for rewards or 'skip' to avoid punishment. The test phase involved a transfer test, where stimuli from the first phase were combined together to form novel compounds without feedback. The control group demonstrated fewer errors compared to opiate-dependent in iduals during the training phase. In the test phase, controls used prior knowledge of both shapes and colors in responding however, opiate-dependent in iduals used shapes but did not use their knowledge of color to modulate responding. When performance during training was equated in the groups using a learning threshold, this difference between groups on the generalization test remained. A deficit in learning generalization might be indicative of group differences in learning strategies in operation during training however, future work is necessary to uncover the specific neural substrates in action during transfer tasks, and to determine the effects of acute methadone dosage on decision-making.
THE “LINKED EVIDENCE APPROACH” TO ASSESS MEDICAL TESTS: A CRITICAL ANALYSIS
Publisher: Cambridge University Press (CUP)
Date: 17-06-2013
DOI: 10.1017/S0266462313000287
Abstract: Objectives: A linked evidence approach (LEA) is the synthesis of systematically acquired evidence on the accuracy of a medical test, its impact on clinical decision making and the effectiveness of consequent treatment options. We aimed to assess the practical utility of this methodology and to develop a decision framework to guide its use. Methods: As Australia has lengthy experience with LEA, we reviewed health technology assessment (HTA) reports informing reimbursement decisions by the Medical Services Advisory Committee (August 2005 to March 2012). Eligibility was determined according to predetermined criteria and data were extracted on test characteristics, evaluation methodologies, and reported difficulties. Fifty percent of the evidence-base was independently analyzed by a second reviewer. Results: Evaluations of medical tests for diagnostic (62 percent), staging (27 percent), and screening (6 percent) purposes were available for eighty-nine different clinical indications. Ninety-six percent of the evaluations used either the full LEA methodology or an abridged version (where evidence is linked through to management changes but not patient outcomes). Sixty-one percent had the full evidence linkage. Twenty-five percent of test evaluations were considered problematic all involving LEA ( n = 22). Problems included: determining test accuracy with an imperfect reference standard (41 percent) assessing likely treatment effectiveness in test positive patients when the new test is more accurate than the comparator (18 percent) and determining probable health benefits in those symptomatic patients ruled out using the test (13 percent). A decision framework was formulated to address these problems. Conclusions: LEA is useful for evaluating medical tests but a stepped approach should be followed to determine what evidence is required for the synthesis.
Epigenetic mechanisms, trauma, and psychopathology: targeting chromatin remodeling complexes
Publisher: Walter de Gruyter GmbH
Date: 07-02-2019
DOI: 10.1515/REVNEURO-2018-0055
Abstract: Environmental pressure affects the genotype throughout different epigenetic processes. There is currently le evidence on the role of epigenetics in developing various mental disorders. A burden of environmental pressure, such as psychological trauma, and its influence on genotype can lead to a variety of psychopathologies. Thus, this study focuses on the epigenetic activity of the complex protein machinery operating on chromatin – the ATP-dependent chromatin remodeling complexes. Although there are several recent studies on the molecular structure, functions, and taxonomy of ATP-dependent chromatin remodeling complexes, the focus of this paper is to highlight the importance of those ‘protein machines’ in developing psychiatric disorders. Data were obtained from human preclinical and clinical studies. The results of this review indicate an importance of ATP-dependent chromatin remodeling complexes in the interaction between environmental factors, including traumatic events, and genetic vulnerability to stress. Several studies indicate that ATP-dependent chromatin remodeling complexes play a crucial role in the development and consolidation of memory, in neurodevelopmental processes, and in etiology depressive-like behavior. Thus, the activity of those ‘protein machines’ emerges as a key factor in the pathophysiology of various psychiatric diseases. It can also be concluded that the limitations of clinical studies may be explained by inappropriate laboratory methods and research paradigms due to the delayed timeframe of biochemical responses to environmental stimuli. Future research in this field may enable a better understanding of the pathophysiology of psychiatric diseases and contribute to the development of novel molecular treatment targets.
Factors underlying risk taking in heroin-dependent individuals: Feedback processing and environmental contingencies
Publisher: Elsevier BV
Date: 09-2018
DOI: 10.1016/J.BBR.2018.04.052
Abstract: Evidence suggests that factors influencing risk-taking include whether decisions are made based on emotions (affective systems) or cognitions (deliberative systems), the processing of feedback (e.g., deciding to attend a rehabilitation facility for opioid addiction treatment after an intervention held by a family member), and attention to environmental contingencies (e.g., considering the probability of an outcome such as the likelihood of contracting tetanus from a shared needle or the gains and losses associated with a decision, such as the benefits and costs of taking drugs). Although drug-dependent in iduals tend to take more risks than non-drug users, the factors underlying risk-taking are unknown. The current study tested, for the first time, the influences of performance feedback (i.e., whether feedback about performance is integrated into decision-making in heroin-dependent in iduals) and attention to environmental contingencies (i.e., the influence of the probability of a loss, the gain amount, and the loss amount associated with a scenario) on risk-taking in heroin-dependent in iduals. Heroin-dependent patients undergoing maintenance therapy for opioid addiction (n = 25) and healthy controls (n = 27) completed the feedback and no-feedback conditions of the Columbia Card Task (CCT). Analyses of covariance, controlling for education and task design (the order in which the CCT conditions were completed) as covariates revealed a significant interaction between (a) probability, gain and loss amount, and group, and (b) group and probability. Our findings suggest that heroin-dependent patients pay less attention to environmental contingencies during risk-taking than controls. Addressing these factors may facilitate greater adherence to treatment programs and lower rates of relapse.
Future-Oriented Repetitive Thought: Pessimistic View of Future in Patients With Alzheimer Disease
Publisher: SAGE Publications
Date: 07-05-2020
Abstract: In this study, we, for the first time, evaluated future-oriented repetitive thought in patients with Alzheimer disease (AD), that is, how they think and worry about the future. We administered the Future-Oriented Repetitive Thought scale to 34 patients with AD and 37 control participants. This scale assessed 3 categories of future-oriented repetitive thought: (1) pessimistic repetitive future thinking (eg, “I think about the possibility of losing people or things that are important to me”), (2) repetitive thinking about future goals (eg, “I make specific plans for how to get things that I want in life”), and (3) positive indulging about the future (eg, “When I picture good things happening in my future, it is as if they were actually happening to me now”). Analysis demonstrated more pessimistic repetitive future thinking, but less repetitive thinking about future goals and positive indulging about the future, in patients with AD than in control participants. Our findings demonstrate a pessimistic view of future in patients with AD, which is possibly attributed to hopelessness and depression.
The effects of clinical motor variables and medication dosage on working memory in Parkinson's disease
Publisher: Elsevier BV
Date: 07-2013
DOI: 10.1016/J.BANDC.2013.04.001
Abstract: In this study, we investigate the interrelationship between clinical variables and working memory (WM) in Parkinson's disease (PD). Specifically, the aim of the study was to investigate the relationship between disease duration, dopaminergic medication dosage, and motor disability (UPDRS score) with WM in in iduals with PD. Accordingly, we recruited three groups of subjects: unmedicated PD patients, medicated PD patients, and healthy controls. All subjects were tested on three WM tasks: short-delay WM, long-delay WM, and the n-back task. Further, PD encompasses a spectrum that can be classified either into akinesia/rigidity or resting tremor as the predominant motor presentation of the disease. In addition to studying medication effects, we tested WM performance in tremor-dominant and akinesia-dominant patients. We further correlated WM performance with disease duration and medication dosage. We found no difference between medicated and unmedicated patients in the short-delay WM task, but medicated patients outperformed unmedicated patients in the long-delay WM and n-back tasks. Interestingly, we also found that akinesia-dominant patients were more impaired than tremor-dominant patients at various WM measures, which is in agreement with prior studies of the relationship between akinesia symptom and basal ganglia dysfunction. Moreover, the results show that disease duration inversely correlates with more demanding WM tasks (long-delay WM and n-back tasks), but medication dosage positively correlates with demanding WM performance. In sum, our results show that WM impairment in PD patients depend on cognitive domain (simple vs. demanding WM task), subtype of PD patients (tremor- vs. akinesia-dominant), as well as disease duration and medication dosage. Our results have implications for the interrelationship between motor and cognitive processes in PD, and for understanding the role of cognitive training in treating motor symptoms in PD.
Computational cognitive models of prefrontal-striatal-hippocampal interactions in Parkinson’s disease and schizophrenia
Publisher: Elsevier BV
Date: 08-2011
DOI: 10.1016/J.NEUNET.2011.02.006
Abstract: Disruption to different components of the prefrontal cortex, basal ganglia, and hippoc al circuits leads to various psychiatric and neurological disorders including Parkinson's disease (PD) and schizophrenia. Medications used to treat these disorders (such as levodopa, dopamine agonists, antipsychotics, among others) affect the prefrontal-striatal-hippoc al circuits in a complex fashion. We have built models of prefrontal-striatal and striatal-hippoc al interactions which simulate cognitive dysfunction in PD and schizophrenia. In these models, we argue that the basal ganglia is key for stimulus-response learning, the hippoc us for stimulus-stimulus representational learning, and the prefrontal cortex for stimulus selection during learning about multidimensional stimuli. In our models, PD is associated with reduced dopamine levels in the basal ganglia and prefrontal cortex. In contrast, the cognitive deficits in schizophrenia are associated primarily with hippoc al dysfunction, while the occurrence of negative symptoms is associated with frontostriatal deficits in a subset of patients. In this paper, we review our past models and provide new simulation results for both PD and schizophrenia. We also describe an extended model that includes simulation of the different functional role of D1 and D2 dopamine receptors in the basal ganglia and prefrontal cortex, a dissociation we argue is essential for understanding the non-uniform effects of levodopa, dopamine agonists, and antipsychotics on cognition. Motivated by clinical and physiological data, we discuss model limitations and challenges to be addressed in future models of these brain disorders.
A Neurocomputational Model of the Effect of Cognitive Load on Freezing of Gait in Parkinson's Disease
Publisher: Frontiers Media SA
Date: 09-01-2017
Effects of combined MAO-B inhibitors and levodopa vs. monotherapy in Parkinson’s disease
Publisher: Frontiers Media SA
Date: 25-07-2014
Off‐track thoughts: Intentional and unintentional mind wandering in Alzheimer's disease
Publisher: Wiley
Date: 11-02-2019
DOI: 10.1111/GGI.13613
Abstract: Despite the recent upsurge of interest in mind wandering (i.e. the occurrence of task-unrelated and stimulus-independent thoughts), little research has attempted to evaluate mind wandering in Alzheimer's disease (AD). We addressed this issue by evaluating intentional and unintentional mind wandering, as well as the relationship between both mind-wandering domains. We also investigated the relationship between mind wandering and depression and working memory. A total of 30 participants with AD and 33 control participants participated in the study. The results showed higher intentional and unintentional mind wandering in AD participants than in controls. In AD participants and controls, both mind wandering domains were significantly correlated with depression, but not with working memory. The present findings show a tendency of AD patients to shift from external stimuli to task-unrelated thoughts and concerns, a tendency that seems to be related with depression. Geriatr Gerontol Int 2019 19: 342-346.
Negative mood induction increases choice of heroin versus food pictures in opiate-dependent individuals: Correlation with self-medication coping motives and subjective reactivity
Publisher: Frontiers Media SA
Date: 15-05-2019
Basal ganglia: physiological, behavioral, and computational studies
Publisher: Frontiers Media SA
Date: 21-08-2014
“La vie en rose”: A positive shift of autobiographical memory in Alzheimer’s Disease
Publisher: Elsevier BV
Date: 2020
DOI: 10.1016/J.ARCHGER.2019.103953
Abstract: We investigated emotional regulation of autobiographical memories in Alzheimer's disease (AD). AD patients and control participants were asked to retrieve memories in response to "happy" and "sad" cues. Participants were also asked to rate the emotional valence of memories at retrieval as well as at the moment the events were encoded. Results showed that both control participants and AD patients rated memories cued by "happy" as more positive when retrieved than when encoded. Both control participants and AD patients also rated memories cued by "sad" as less negative when retrieved than when encoded. Furthermore, emotional regulation (i.e., emotional variation across retrieval and encoding of memories) was significantly correlated with depression in AD patients and control participants. These findings suggest a cognitive reappraisal strategy by which AD patients 1) attribute positive meaning to positive memories, and 2) view negative emotional memories from a less negative perspective, demonstrating an ability to re-interpret the meaning of these memories, and thereby, to change their emotional impact. This reappraisal strategy seems to be related with depression as depressive symptoms was inversely correlated with cognitive reappraisal in AD.
A computational model of altered gait patterns in parkinson's disease patients negotiating narrow doorways
Publisher: Frontiers Media SA
Date: 2014
A commentary on “Antipsychotic-induced Parkinsonism is associated with working memory deficits in schizophrenia-spectrum disordersâ€
Publisher: Frontiers Media SA
Date: 27-05-2015
Time representation in reinforcement learning models of the basal ganglia
Publisher: Frontiers Media SA
Date: 2014
Drift diffusion model of reward and punishment learning in schizophrenia: Modeling and experimental data
Publisher: Elsevier BV
Date: 09-2015
DOI: 10.1016/J.BBR.2015.05.024
Abstract: In this study, we tested reward- and punishment learning performance using a probabilistic classification learning task in patients with schizophrenia (n=37) and healthy controls (n=48). We also fit subjects' data using a Drift Diffusion Model (DDM) of simple decisions to investigate which components of the decision process differ between patients and controls. Modeling results show between-group differences in multiple components of the decision process. Specifically, patients had slower motor/encoding time, higher response caution (favoring accuracy over speed), and a deficit in classification learning for punishment, but not reward, trials. The results suggest that patients with schizophrenia adopt a compensatory strategy of favoring accuracy over speed to improve performance, yet still show signs of a deficit in learning based on negative feedback. Our data highlights the importance of applying fitting models (particularly drift diffusion models) to behavioral data. The implications of these findings are discussed relative to theories of schizophrenia and cognitive processing.
Feature Selection for the Classification of Alzheimer's Disease Data
Publisher: ACM
Date: 12-01-2020
Methylphenidate improves executive functions in patients with traumatic brain injuries: a feasibility trial via the idiographic approach
Publisher: Springer Science and Business Media LLC
Date: 19-07-2021
DOI: 10.1186/S12883-020-01663-X
Abstract: Road traffic accidents are known to be the main cause of traumatic brain injury (TBI). TBI is also a leading cause of death and disability. This study, by means of the idiographic approach (single-case experimental designs using multiple-baseline designs), has examined whether methylphenidate (MPH - trade name Ritalin) had a differential effect on cognitive measures among patients with TBI with the sequel of acute and chronic post-concussion syndromes. The effect on gender was also explored. In comparison with healthy controls, patients with TBI (acute and chronic) and accompanying mild cognitive impairment (MCI) were screened for their integrity of executive functioning. Twenty-four patients exhibiting executive dysfunction (ED) were then instituted with the pharmacological intervention methylphenidate (MPH). The methylphenidate was administered using an uncontrolled, open label design. The administration of methylphenidate impacted ED in the TBI group but had no effect on mood. Attenuation of ED was more apparent in the chronic phases of TBI. The effect on gender was not statistically significant with regard to the observed changes. To our knowledge, this is the first feasibility trial from the Arabian Gulf to report the performance of a TBI population with mild cognitive impairment according to the IQCODE Arabic version. This investigation confirms anecdotal observations of methylphenidate having the potential to attenuate cognitive impairment particularly those functions that are critically involved in the integrity of executive functioning. The present feasibility trial should be followed by nomothetic studies such as those that adhere to the protocol of the randomized controlled trial. This evidence-based research is the foundation for intervention and future resource allocation by policy- or public health decision-makers.
Intolerance of uncertainty and conditioned place preference in opioid addiction
Publisher: PeerJ
Date: 21-05-2018
DOI: 10.7717/PEERJ.4775
Abstract: Several personality factors have been implicated in vulnerability to addiction by impacting learning and decision making. One such factor is intolerance of uncertainty (IU), the tendency to perceive uncertain situations negatively and avoid them. Conditioned place preference (CPP), which compares preference for contexts paired with reward, has been used to examine the motivation for both drug and non-drug rewards. However, preference for locations associated with non-drug reward, as well as the potential influence of IU, has not been thoroughly studied in in iduals with addiction. In the current study, we examined CPP using a computer-based task in a s le of addicted in iduals undergoing opioid maintenance treatment and never-addicted controls. Patients were confirmed to have higher IU than controls. In the CPP task, the two groups did not differ in overall time spent in the previously-rewarded context. However, controls were more likely than patients to immediately return to this context. Contrary to our predictions, IU was not a significant predictor of preference for the previously-rewarded context, although higher IU in controls was associated with a higher number of rewards obtained in the task. No such relationship was found in patients.
Examining the Mediating Role of Stress in the Relationship Between Mindfulness and Depression and Anxiety: Testing the Mindfulness Stress-Buffering Model
Publisher: Springer Science and Business Media LLC
Date: 10-05-2019
Learning and Generalization in Healthy Aging
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 03-2012
Impulse Control Disorders in Parkinson's Disease Are Associated with Dysfunction in Stimulus Valuation But Not Action Valuation
Publisher: Society for Neuroscience
Date: 04-06-2014
How Knowledge of Ancient Egyptian Women Can Influence Today’s Gender Role: Does History Matter in Gender Psychology?
Publisher: Frontiers Media SA
Date: 05-01-2017
On the Complexity of Brain Disorders: A Symptom-Based Approach
Publisher: Frontiers Media SA
Date: 23-02-2016
Fronto-striatal gray matter contributions to discrimination learning in Parkinson's disease
Publisher: Frontiers Media SA
Date: 2013
Applying Big Data Methods to Understanding Human Behavior and Health
Publisher: Frontiers Media SA
Date: 16-10-2018
Computational investigation of mechanistic insights of Aβ42 interactions against extracellular domain of nAChRα7 in Alzheimer’s disease
Publisher: Informa UK Limited
Date: 09-01-2019
DOI: 10.1080/00207454.2018.1543670
Abstract: Amyloid beta (Aβ) 1-42, which is a basic constituent of amyloid plaques, binds with extracellular transmembrane receptor nicotine acetylcholine receptor α7 (nAChRα7) in Alzheimer's disease. In the current study, a computational approach was employed to explore the active binding sites of nAChRα7 through Aβ 1-42 interactions and their involvement in the activation of downstream signalling pathways. Sequential and structural analyses were performed on the extracellular part of nAChRα7 to identify its core active binding site. Results showed that a conserved residual pattern and well superimposed structures were observed in all nAChRs proteins. Molecular docking servers were used to predict the common interactive residues in nAChRα7 and Aβ1-42 proteins. The docking profile results showed some common interactive residues such as Glu22, Ala42 and Trp171 may consider as the active key player in the activation of downstream signalling pathways. Moreover, the signal communication and receiving efficacy of best-docked complexes was checked through DynOmic online server. Furthermore, the results from molecular dynamic simulation experiment showed the stability of nAChRα7. The generated root mean square deviations and fluctuations (RMSD/F), solvent accessible surface area (SASA) and radius of gyration (Rg) graphs of nAChRα7 also showed its backbone stability and compactness, respectively. Taken together, our predicted results intimated the structural insight on the molecular interactions of beta amyloid protein involved in the activation of nAChRα7 receptor. In future, a better understanding of nAChRα7 and their interconnected proteins signalling cascade may be consider as target to cure Alzheimer's disease.
Mathematics, anxiety, and the brain
Publisher: Walter de Gruyter GmbH
Date: 03-02-2017
DOI: 10.1515/REVNEURO-2016-0065
Abstract: Given that achievement in learning mathematics at school correlates with work and social achievements, it is important to understand the cognitive processes underlying abilities to learn mathematics efficiently as well as reasons underlying the occurrence of mathematics anxiety (i.e. feelings of tension and fear upon facing mathematical problems or numbers) among certain in iduals. Over the last two decades, many studies have shown that learning mathematical and numerical concepts relies on many cognitive processes, including working memory, spatial skills, and linguistic abilities. In this review, we discuss the relationship between mathematical learning and cognitive processes as well as the neural substrates underlying successful mathematical learning and problem solving. More importantly, we also discuss the relationship between these cognitive processes, mathematics anxiety, and mathematics learning disabilities (dyscalculia). Our review shows that mathematical cognition relies on a complex brain network, and dysfunction to different segments of this network leads to varying manifestations of mathematical learning disabilities.
The thalamus as a relay station and gatekeeper: Relevance to brain disorders
Publisher: Walter de Gruyter GmbH
Date: 02-2017
DOI: 10.1515/REVNEURO-2016-0067
Abstract: Here, we provide a review of behavioural, cognitive, and neural studies of the thalamus, including its role in attention, consciousness, sleep, and motor processes. We further discuss neuropsychological and brain disorders associated with thalamus function, including Parkinson’s disease, Alzheimer’s disease, Korsakoff’s syndrome, and sleep disorders. Importantly, we highlight how thalamus-related processes and disorders can be explained by the role of the thalamus as a relay station.
Corrigendum to “Adenosine role in brain functions: Pathophysiological influence on Parkinson’s disease and other brain disorders” [Pharmacol. Rep. 70 (2018) 661–667]
Publisher: Springer Science and Business Media LLC
Date: 06-2019
Evaluating the Sustained Attention Response Task to Quantify Cognitive Fluctuations in Dementia With Lewy Bodies
Publisher: SAGE Publications
Date: 31-10-2019
Abstract: Cognitive fluctuations (CFs) are a core diagnostic feature of dementia with Lewy bodies (DLB). Detection of CF is still mostly based on subjective reports from the patient or informant more quantitative measures are likely to improve the accuracy for the diagnosis of DLB. The purpose of the current study is to test whether performance on the Sustained Attention Response Task (SART) could distinguish those patients with DLB with and without CF. Twenty-four patients with DLB were tested on the SART and performance was related to scores on the Clinical Assessment of Fluctuations (CAFs) and One Day Fluctuation Assessment Scale (ODFAS). The number of “misses” made was a significant predictor of their fluctuation severity, attentional performance, disorganized thinking, and language production ratings on the ODFAS. However, measures on the SART did not correlate with measures on the CAF scale. In conclusion, these findings suggest that SART is a feasible measure of sustained attention in this population and has clinical and diagnostic relevance to the measurement of CF, particularly those aspects measured by the ODFAS.
Impulsivity and its relationship with anxiety, depression and stress
Publisher: Elsevier BV
Date: 04-2017
DOI: 10.1016/J.COMPPSYCH.2017.01.013
Abstract: We aimed to assess the association between depression, anxiety, stress and impulsivity with respect to age. The Depression, Anxiety and Stress Scale (DASS-42) and the Barratt Impulsiveness Scale (BIS-11) were administered to 145 in iduals. Due to a negative correlation between age, BIS-11 and DASS-42 subscales, participants were ided into three groups: young-aged (18-30years), middle-aged (31-49years) and old-aged (≥50years). Subjects from old-aged group had significantly lower scores of depression, anxiety, stress and impulsivity compared to those from younger groups. Anxiety, followed by stress and depression, was the strongest predictor of BIS-11 total score in young-aged and middle-aged in iduals. There were no significant differences in the correlations between BIS-11 total score, depression, anxiety and stress in old-aged in iduals. Our results indicate that the levels of depression, anxiety, stress and impulsivity decrease with age. Additionally, age might moderate the effect of depression, anxiety and stress on impulsivity.
BDNF val66met genotype and schizotypal personality traits interact to influence probabilistic association learning
Publisher: Elsevier BV
Date: 11-2014
DOI: 10.1016/J.BBR.2014.07.041
Abstract: The brain derived neurotrophic factor (BDNF) val66met polymorphism rs6265 influences learning and may represent a risk factor for schizophrenia. Healthy people with high schizotypal personality traits display cognitive deficits that are similar to but not as severe as those observed in schizophrenia and they can be studied without confounds of antipsychotics or chronic illness. How genetic variation in BDNF may impact learning in in iduals falling along the schizophrenia spectrum is unknown. We predicted that schizotypal personality traits would influence learning and that schizotypal personality-based differences in learning would vary depending on the BDNF val66met genotype. Eighty-nine healthy adults completed the Schizotypal Personality Questionnaire (SPQ) and a probabilistic association learning test. Blood s les were genotyped for the BDNF val66met polymorphism. An ANOVA was performed with BDNF genotype (val homozygotes and met-carriers) and SPQ score (high/low) as grouping variables and probabilistic association learning as the dependent variable. Participants with low SPQ scores (fewer schizotypal personality traits) showed significantly better learning than those with high SPQ scores. BDNF met-carriers displaying few schizotypal personality traits performed best, whereas BDNF met-carriers displaying high schizotypal personality traits performed worst. Thus, the BDNF val66met polymorphism appears to influence probabilistic association learning differently depending on the extent of schizotypal personality traits displayed.
Dopamine modulates striatal response to reward and punishment in patients with Parkinson’s disease
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 02-05-2018
Social Cognition in Psychosis
Publisher: Elsevier
Date: 2019
A Role for Dopamine in Temporal Decision Making and Reward Maximization in Parkinsonism
Publisher: Society for Neuroscience
Date: 19-11-2008
DOI: 10.1523/JNEUROSCI.3116-08.2008
Abstract: Converging evidence implicates striatal dopamine (DA) in reinforcement learning, such that DA increases enhance “Go learning” to pursue actions with rewarding outcomes, whereas DA decreases enhance “NoGo learning” to avoid non-rewarding actions. Here we test whether these effects apply to the response time domain. We employ a novel paradigm which requires the adjustment of response times to a single response. Reward probability varies as a function of response time, whereas reward magnitude changes in the opposite direction. In the control condition, these factors exactly cancel, such that the expected value across time is constant (CEV). In two other conditions, expected value increases (IEV) or decreases (DEV), such that reward maximization requires either speeding up (Go learning) or slowing down (NoGo learning) relative to the CEV condition. We tested patients with Parkinson's disease (depleted striatal DA levels) on and off dopaminergic medication, compared with age-matched controls. While medicated, patients were better at speeding up in the DEV relative to CEV conditions. Conversely, nonmedicated patients were better at slowing down to maximize reward in the IEV condition. These effects of DA manipulation on cumulative Go/NoGo response time adaptation were captured with our a priori computational model of the basal ganglia, previously applied only to forced-choice tasks. There were also robust trial-to-trial changes in response time, but these single trial adaptations were not affected by disease or medication and are posited to rely on extrastriatal, possibly prefrontal, structures.
Positive facial expressions during retrieval of self-defining memories
Publisher: IMR Press
Date: 15-08-2018
DOI: 10.31083/JIN-170073
On the relationship among different motor processes: a computational modeling approach
Publisher: Frontiers Media SA
Date: 18-03-2015
Hold Your Horses: Impulsivity, Deep Brain Stimulation, and Medication in Parkinsonism
Publisher: American Association for the Advancement of Science (AAAS)
Date: 23-11-2007
Abstract: Deep brain stimulation (DBS) of the subthalamic nucleus markedly improves the motor symptoms of Parkinson's disease, but causes cognitive side effects such as impulsivity. We showed that DBS selectively interferes with the normal ability to slow down when faced with decision conflict. While on DBS, patients actually sped up their decisions under high-conflict conditions. This form of impulsivity was not affected by dopaminergic medication status. Instead, medication impaired patients' ability to learn from negative decision outcomes. These findings implicate independent mechanisms leading to impulsivity in treated Parkinson's patients and were predicted by a single neurocomputational model of the basal ganglia.
Testosterone, DHEA and DHEA-S in patients with schizophrenia: A systematic review and meta-analysis
Publisher: Elsevier BV
Date: 03-2018
DOI: 10.1016/J.PSYNEUEN.2018.01.007
Abstract: Neuroactive steroids, including testosterone, dehydroepiandrosterone (DHEA) and its sulfate (DHEA-S) might play an important role in the pathophysiology of schizophrenia. Therefore, we performed a systematic review and meta-analysis of studies comparing the levels of testosterone, DHEA and DHEA-S in patients with schizophrenia and healthy controls. We searched electronic databases from their inception until Oct 29, 2017. Effect size (ES) estimates were calculated as Hedges' g. Data analysis was performed using random-effects models. Our analysis included 34 eligible studies, representing 1742 patients and 1604 controls. Main analysis revealed elevated DHEA-S levels in the whole group of patients (ES = 0.75, 95%CI: 0.23-1.28, p = 0.005). In subgroup analyses, patients with first-episode psychosis (FEP) had significantly higher levels of free testosterone (ES = 1.21, 95%CI: 0.30-2.12, p = 0.009) and DHEA-S (ES = 1.19, 95%CI: 0.66-1.71, p < 0.001). Acutely relapsed schizophrenia patients presented significantly higher levels of total testosterone (ES = 0.50, 95%CI: 0.21-0.70, p < 0.001). Total testosterone levels were also elevated in stable multi-episode schizophrenia (sMES) females (ES = 0.56, 95%CI: 0.33-0.80, p < 0.001) and reduced in sMES males (ES = -0.62, 95%CI: -1.07 to 0.18, p = 0.006). Increased levels of biologically active, free testosterone and DHEA-S in FEP suggest that these alterations might appear as a response to stress that becomes blunted during subsequent exacerbations of schizophrenia. Differential changes in total testosterone levels in male and female sMES patients might represent medication effects related to prolactin-releasing effects of antipsychotics.
The Role of Informative and Ambiguous Feedback in Avoidance Behavior: Empirical and Computational Findings
Publisher: Public Library of Science (PLoS)
Date: 02-12-2015
Impaired homeostatic regulation of feedback inhibition associated with system deficiency to detect fluctuation in stimulus intensity: a simulation study
Publisher: Elsevier BV
Date: 03-2015
The influence of trial order on learning from reward vs. punishment in a probabilistic categorization task: experimental and computational analyses
Publisher: Frontiers Media SA
Date: 24-07-2015
An extended reinforcement learning model of basal ganglia to understand the contributions of serotonin and dopamine in risk-based decision making, reward prediction, and punishment learning
Publisher: Frontiers Media SA
Date: 16-04-2014
Exploring the cognitive and motor functions of the basal ganglia: an integrative review of computational cognitive neuroscience models
Publisher: Frontiers Media SA
Date: 2013
Interactions Between Variation in Candidate Genes and Environmental Factors in the Etiology of Schizophrenia and Bipolar Disorder: a Systematic Review
Publisher: Springer Science and Business Media LLC
Date: 18-08-2017
A Neurocomputational Model of Dopamine and Prefrontal–Striatal Interactions during Multicue Category Learning by Parkinson Patients
Publisher: MIT Press - Journals
Date: 2011
Abstract: Most existing models of dopamine and learning in Parkinson disease (PD) focus on simulating the role of basal ganglia dopamine in reinforcement learning. Much data argue, however, for a critical role for prefrontal cortex (PFC) dopamine in stimulus selection in attentional learning. Here, we present a new computational model that simulates performance in multicue category learning, such as the “weather prediction” task. The model addresses how PD and dopamine medications affect stimulus selection processes, which mediate reinforcement learning. In this model, PFC dopamine is key for attentional learning, whereas basal ganglia dopamine, consistent with other models, is key for reinforcement and motor learning. The model assumes that competitive dynamics among PFC neurons is the neural mechanism underlying stimulus selection with limited attentional resources, whereas competitive dynamics among striatal neurons is the neural mechanism underlying action selection. According to our model, PD is associated with decreased phasic and tonic dopamine levels in both PFC and basal ganglia. We assume that dopamine medications increase dopamine levels in both the basal ganglia and PFC, which, in turn, increase tonic dopamine levels but decrease the magnitude of phasic dopamine signaling in these brain structures. Increase of tonic dopamine levels in the simulated PFC enhances attentional shifting performance. The model provides a mechanistic account for several phenomena, including (a) medicated PD patients are more impaired at multicue probabilistic category learning than unmedicated patients and (b) medicated PD patients opt out of reversal when there are alternative and redundant cue dimensions.
Multiscale models of pharmacological, immunological and neurostimulation treatments in Alzheimer's disease
Publisher: Elsevier BV
Date: 2016
The relationship between childhood trauma, early-life stress, and alcohol and drug use, abuse, and addiction: An integrative review
Publisher: Springer Science and Business Media LLC
Date: 28-08-2018
Maladaptive avoidance patterns in Parkinson’s disease are exacerbated by symptoms of depression
Publisher: Elsevier BV
Date: 03-2020
Examining Perceived Stress, Childhood Trauma and Interpersonal Trauma in Individuals With Drug Addiction
Publisher: SAGE Publications
Date: 23-03-2019
Abstract: The investigation of psychosocial factors in relation to opiate addiction is limited and typically uses binary measures to assess how incidences of childhood trauma correlate with addiction. There has also been a lack of enquiry into how experiences of noninterpersonal versus interpersonal trauma may impact drug use addiction. In this regard, the current study utilized a novel measurement of interpersonal versus noninterpersonal lifetime trauma and a scale assessing severity of childhood trauma to examine how these factors may impact patients with opioid addiction. The interaction between these factors and current perceived stress was also examined. Thirty-six opioid-dependent in iduals (recruited from the Drug Health Services and Opioid Treatment Program at the Royal Prince Alfred Hospital in Sydney, Australia) and 33 healthy controls completed the Childhood Maltreatment Questionnaire, Lifetime Trauma Survey, and Perceived Levels of Stress Scale. The patient group reported significantly greater childhood trauma severity, more incidences of lifetime trauma, and higher perceived stress than controls. Logistic regression analyses indicated that the severity of childhood trauma was more strongly associated with addiction status than perceived stress. A greater number of lifetime trauma incidence was the best predictor of addiction. Contrary to expectations, noninterpersonal lifetime trauma was a better predictor of addiction status than was interpersonal lifetime trauma. Results suggest that lifetime trauma and childhood trauma may play an important factor in opioid addiction over what can be accounted for by stress.
Alterations in white matter network topology contribute to freezing of gait in Parkinson’s disease
Publisher: Springer Science and Business Media LLC
Date: 03-04-2018
DOI: 10.1007/S00415-018-8846-3
Abstract: Freezing of gait (FOG) is a common symptom in advanced Parkinson's disease (PD). Despite current advances, the neural mechanisms underpinning this disturbance remain poorly understood. To this end, we investigated the structural organisation of the white matter connectome in PD freezers and PD non-freezers. We hypothesized that freezers would show an altered network architecture, which could hinder the effective information processing that characterizes the disorder. Twenty-six freezers and twenty-four well-matched non-freezers were included in this study. Using diffusion tensor imaging, we investigated the modularity and integration of the regional connectome by calculating the module degree z score and the participation coefficient, respectively. Compared to non-freezers, freezers demonstrated lower participation coefficients in the right caudate, thalamus, and hippoc us, as well as within superior frontal and parietal cortical regions. Importantly, several of these nodes were found within the brain's 'rich club'. Furthermore, group differences in module degree z scores within cortical frontal and sensory processing areas were found. Together, our results suggest that changes in the structural network topology contribute to the manifestation of FOG in PD, specifically due to a lack of structural integration between key information processing hubs of the brain.
Multi-Objective Service Composition Using Reinforcement Learning
Publisher: Springer Berlin Heidelberg
Date: 2013
The face of memory: experiential avoidance and facial expressions during the retrieval of autobiographical memories
Publisher: Informa UK Limited
Date: 07-2019
Selective A 2A receptors blockade reduces degeneration of substantia nigra dopamine neurons in a rotenone-induced rat model of Parkinson’s disease: A histological study
Publisher: Elsevier BV
Date: 03-2017
DOI: 10.1016/J.NEULET.2017.02.036
Abstract: Parkinson's disease (PD) is characterized by a loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc). Adenosine is a neuromodulator that inhibit the release of dopamine via a disinhibitory mechanism. In this study, we investigated the neuroprotective effect of 8-cyclopentyl-1,3-dipropylxanthine and ZM241385 (respectively, A
Neural substrates and potential treatments for levodopa-induced dyskinesias in Parkinson’s disease
Publisher: Walter de Gruyter GmbH
Date: 30-06-2016
DOI: 10.1515/REVNEURO-2016-0009
Abstract: Parkinson’s disease (PD) is primarily a motor disorder that involves the gradual loss of motor function. Symptoms are observed initially in the extremities, such as hands and arms, while advanced stages of the disease can effect blinking, swallowing, speaking, and breathing. PD is a neurodegenerative disease, with dopaminergic neuronal loss occurring in the substantia nigra pars compacta, thus disrupting basal ganglia functions. This leads to downstream effects on other neurotransmitter systems such as glutamate, γ-aminobutyric acid, and serotonin. To date, one of the main treatments for PD is levodopa. While it is generally very effective, prolonged treatments lead to levodopa-induced dyskinesia (LID). LID encompasses a family of symptoms ranging from uncontrolled repetitive movements to sustained muscle contractions. In many cases, the symptoms of LID can cause more grief than PD itself. The purpose of this review is to discuss the possible clinical features, cognitive correlates, neural substrates, as well as potential psychopharmacological and surgical (including nondopaminergic and deep brain stimulation) treatments of LID.
Childhood traumatic events and types of auditory verbal hallucinations in first-episode schizophrenia patients
Publisher: Elsevier BV
Date: 04-2016
DOI: 10.1016/J.COMPPSYCH.2015.12.003
Abstract: Evidence is accumulating that childhood trauma might be associated with higher severity of positive symptoms in patients with psychosis and higher incidence of psychotic experiences in non-clinical populations. However, it remains unknown whether the history of childhood trauma might be associated with particular types of auditory verbal hallucinations (AVH). We assessed childhood trauma using the Early Trauma Inventory Self-Report - Short Form (ETISR-SF) in 94 first-episode schizophrenia (FES) patients. Lifetime psychopathology was evaluated using the Operational Criteria for Psychotic Illness (OPCRIT) checklist, while symptoms on the day of assessment were examined using the Positive and Negative Syndrome Scale (PANSS). Based on ETISR-SF, patients were ided into those with and without the history of childhood trauma: FES(+) and FES(-) patients. FES(+) patients had significantly higher total number of AVH types and Schneiderian first-rank AVH as well as significantly higher PANSS P3 item score (hallucinatory behavior) in comparison with FES(-) patients. They experienced significantly more frequently third person AVH and abusive/accusatory ersecutory voices. These differences remained significant after controlling for education, PANSS depression factor score and chlorpromazine equivalent. Linear regression analysis revealed that the total number of AVH types was predicted by sexual abuse score after controlling for above mentioned confounders. This effect was significant only in females. Our results indicate that the history of childhood trauma, especially sexual abuse, is associated with higher number AVH in females but not in males. Third person AVH and abusive/accusatory ersecutory voices, representing Schneiderian first-rank symptoms, might be particularly related to childhood traumatic events.
The effect of attentional bias modification training on food intake in overweight and obese women
Publisher: SAGE Publications
Date: 09-03-2018
Abstract: This study modified food attentional biases via computerized attentional bias modification training and examined the effects on food intake. Overweight women were randomly allocated to (1) direct attention away from food (“attentional-training”), (2) direct attention at random to food or neutral (“placebo”), or (3) no training (“control”). In iduals then completed a taste test. Those in the attentional-training consumed on average 600 kJ less of total food compared to the placebo. Those in the attentional-training had a reduction in food attentional bias compared to the placebo group, when controlling for executive function. Attentional-training seems to reduce high-calorie intake in overweight women.
The application of unsupervised clustering methods to Alzheimer’s disease
Publisher: Frontiers Media SA
Date: 24-05-2019
A neural model of hippocampal–striatal interactions in associative learning and transfer generalization in various neurological and psychiatric patients
Publisher: Elsevier BV
Date: 11-2010
Interrelations between cognitive dysfunction and motor symptoms of Parkinson's disease: Behavioral and neural studies
Publisher: Walter de Gruyter GmbH
Date: 07-2016
DOI: 10.1515/REVNEURO-2015-0070
Abstract: Parkinson’s disease (PD) is characterized by a range of motor symptoms. Besides the cardinal symptoms (tremor, bradykinesia/akinesia, and rigidity), PD patients also show other motor deficits, including gait disturbance, speech deficits, and impaired handwriting. However, along with these key motor symptoms, PD patients also experience cognitive deficits in attention, executive function, working memory, and learning. Recent evidence suggests that these motor and cognitive deficits of PD are not completely dissociable, as aspects of cognitive dysfunction can impact motor performance in PD. In this article, we provide a review of behavioral and neural studies on the associations between motor symptoms and cognitive deficits in PD, specifically akinesia/bradykinesia, tremor, gait, handwriting, precision grip, and speech production. This review paves the way for providing a framework for understanding how treatment of cognitive dysfunction, for ex le cognitive rehabilitation programs, may in turn influence the motor symptoms of PD.
Postural instability and falls in Parkinson's disease
Publisher: Walter de Gruyter GmbH
Date: 07-2016
DOI: 10.1515/REVNEURO-2016-0002
Abstract: Postural instability (PI) is one of the most debilitating motor symptoms of Parkinson’s disease (PD), as it is associated with an increased risk of falls and subsequent medical complications (e.g. fractures), fear of falling, decreased mobility, self-restricted physical activity, social isolation, and decreased quality of life. The pathophysiological mechanisms underlying PI in PD remain elusive. This short review provides a critical summary of the literature on PI in PD, covering the clinical features, the neural and cognitive substrates, and the effects of dopaminergic medications and deep brain stimulation. The delayed effect of dopaminergic medication combined with the success of extrastriatal deep brain stimulation suggests that PI involves neurotransmitter systems other than dopamine and brain regions extending beyond the basal ganglia, further challenging the traditional view of PD as a predominantly single-system neurodegenerative disease.
The exploration of novel Alzheimer’s therapeutic agents from the pool of FDA approved medicines using drug repositioning, enzyme inhibition and kinetic mechanism approaches
Publisher: Elsevier BV
Date: 2019
DOI: 10.1016/J.BIOPHA.2018.11.115
Abstract: Novel drug development is onerous, time consuming and overpriced process with particularly low success and relatively high enfeebling rates. To overcome this burden, drug repositioning approach is being used to predict the possible therapeutic effects of FDA approved drugs in different diseases. Herein, we designed a computational and enzyme inhibitory mechanistic approach to fetch the promising drugs from the pool of FDA approved drugs against AD. The binding interaction patterns and conformations of screened drugs within active region of AChE were confirmed through molecular docking profiles. The possible associations of selected drugs with AD genes were predicted by pharmacogenomics analysis and confirmed through data mining. The stability behaviour of docked complexes (Drugs-AChE) were checked by MD simulations. The possible therapeutic potential of repositioned drugs against AChE were checked by in vitro analysis. Taken together, Cinitapride displayed a comparable results with standard and can be used as possible therapeutic agent in the treatment of AD.
Cognitive correlates of psychosis in patients with Parkinson's disease
Publisher: Informa UK Limited
Date: 21-01-2014
DOI: 10.1080/13546805.2013.877385
Abstract: Psychosis and hallucinations occur in 20-30% of patients with Parkinson's disease (PD). In the current study, we investigate cognitive functions in relation to the occurrence of psychosis in PD patients. We tested three groups of subjects - PD with psychosis, PD without psychosis and healthy controls - on working memory, learning and transitive inference tasks, which are known to assess prefrontal, basal ganglia and hippoc al functions. In the working memory task, results show that patients with and without psychosis were more impaired than the healthy control group. In the transitive inference task, we did not find any difference among the groups in the learning phase performance. Importantly, PD patients with psychosis were more impaired than both PD patients without psychosis and controls at transitive inference. We also found that the severity of psychotic symptoms in PD patients [as measured by the Unified Parkinson Disease Rating Scale Thought Disorder (UPDRS TD) item] is directly associated with the severity of cognitive impairment [as measured by the mini-mental status exam (MMSE)], sleep disturbance [as measured by the Scales for Outcome in Parkinson Disease (SCOPA) sleep scale] and transitive inference (although the latter did not reach significance). Although hypothetical, our data may suggest that the hippoc us is a neural substrate underlying the occurrence of psychosis, sleep disturbance and cognitive impairment in PD patients.
Insecure Attachment and Subclinical Depression, Anxiety, and Stress: A Three-Dimensional Model of Personality Self-Regulation As a Mediator
Publisher: Informa UK Limited
Date: 23-10-2018
DOI: 10.1080/00223980.2018.1468727
Abstract: Although the effects of insecure attachment on vulnerability, incidence, and developing mental disorders have been confirmed by many studies, the mechanism of this effect is still unknown. Therefore, the main aim of this study was to investigate the mediating and moderating role of the three-dimensional model of personality self-regulation in the relationship between insecure attachment and subclinical depression, anxiety, and stress. Four hundred Iranian students at Shiraz University were recruited and completed the following scales: the Revised Adult Attachment, Depression Anxiety Stress, Integrative Self-Knowledge, Mindful Attention Awareness, Self-Control, and Self-Compassion. Results showed that there was a moderate correlation among all the variables under study in the expected directions. Multiple mediating models analyses indicated that regarding the relationship between insecure attachment and depression, the components of integrative self-knowledge, self-control, and self-compassion functioned as mediators. However, regarding the relationship between insecure attachment and anxiety and stress, the components of integrative self-knowledge, mindfulness, and self-compassion relatively functioned as mediators. Further, our results showed that only mindfulness and self-compassion were identified as moderators in the relationship between insecure attachment and depression. It is concluded that insecure attachment may cause psychological damage due to deficiency in the components of the three-dimensional model of personality self-regulation, and that mindfulness and self-compassion may play a protective role in the relationship between insecure attachment and depression.
Using TD learning to simulate working memory performance in a model of the prefrontal cortex and basal ganglia
Publisher: Elsevier BV
Date: 12-2007
Modelling change in neurocognition, symptoms and functioning in young people with emerging mental disorders
Publisher: Elsevier BV
Date: 12-2020
Assessment of the Association Between Cigarette Smoking and Cognitive Performance in Patients With Schizophrenia-Spectrum Disorders: A Case-Control Study
Publisher: Frontiers Media SA
Date: 03-12-2018
Pharmacoinformatics exploration of polyphenol oxidases leading to novel inhibitors by virtual screening and molecular dynamic simulation study
Publisher: Elsevier BV
Date: 06-2017
DOI: 10.1016/J.COMPBIOLCHEM.2017.02.012
Abstract: Polyphenol oxidases (PPOs)/tyrosinases are metal-dependent enzymes and known as important targets for melanogenesis. Although considerable attempts have been conducted to control the melanin-associated diseases by using various inhibitors. However, the exploration of the best anti-melanin inhibitor without side effect still remains a challenge in drug discovery. In present study, protein structure prediction, ligand-based pharmacophore modeling, virtual screening, molecular docking and dynamic simulation study were used to screen the strong novel inhibitor to cure melanogenesis. The 3D structures of PPO1 and PPO2 were built through homology modeling, while the 3D crystal structures of PPO3 and PPO4 were retrieved from PDB. Pharmacophore modeling was performed using LigandScout 3.1 software and top five models were selected to screen the libraries (2601 of Aurora and 727, 842 of ZINC). Top 10 hit compounds (C1-10) were short-listed having strong binding affinities for PPO1-4. Drug and synthetic accessibility (SA) scores along with absorption, distribution, metabolism, excretion and toxicity (ADMET) assessment were employed to scrutinize the best lead hit. C4 (name) hit showed the best predicted SA score (5.75), ADMET properties and drug-likeness behavior among the short-listed compounds. Furthermore, docking simulations were performed to check the binding affinity of C1-C10 compounds against target proteins (PPOs). The binding affinity values of complex between C4 and PPOs were higher than those of other complexes (-11.70, -12.1, -9.90 and -11.20kcal/mol with PPO1, PPO2, PPO3, or PPO4, respectively). From comparative docking energy and binding analyses, PPO2 may be considered as better target for melanogenesis than others. The potential binding modes of C4, C8 and C10 against PPO2 were explored using molecular dynamics simulations. The root mean square deviation and fluctuation (RMSD/RMSF) graphs results depict the significance of C4 over the other compounds. Overall, bioactivity and ligand efficiency profiles suggested that the proposed hit may be more effective inhibitors for melanogenesis.
Cue-elicited craving and human Pavlovian-to-instrumental transfer
Publisher: Informa UK Limited
Date: 09-01-2019
Finding Novel Anti-carcinomas Compounds by Targeting SFRP4 Through Molecular Modeling, Docking and Dynamic Simulation Studies
Publisher: Bentham Science Publishers Ltd.
Date: 24-05-2018
DOI: 10.2174/1573409914666180112100122
Abstract: Secreted Frizzled-Related Protein 4 (SFRP4) is a glycoprotein that acts as a competitor of both canonical and non-canonical Wnt pathways. SFRP4 is mostly expressed in ovary and plays a significant role as a target molecule to cure ovarian carcinoma. Multiple chemical agonists are being used to cure ovary melanoma. We are interested in theoretically analyzing the compounds through computational approaches for their potential inhibitory effects against SFRP4. Compounds were sketched in Chemsketch drawing tool and minimized through chimera tool. Because the crystal structure of SFRP4 is not available in Protein Data Bank, homology modeling approach was used to predict Three-Dimensional (3D) crystal structure of SFRP4. Moreover, multiple computational approaches such as molecular docking and Molecular Dynamic (MD) simulations along with various online tools were employed to screen the best inhibitor against ovary melanoma. The docking results showed that 1d and 1e compounds revealed significant binding energy values (-9.10 and -9.00 kcal/mol, respectively) compared with the standard drugs such as cis-platin and docetaxel (-3.30, -10.80 kcal/mol), respectively. Moreover, MD simulation results showed that 1d has little fluctuations throughout the simulation period as depicted by the root mean square deviation and root mean square fluctuation graphs. The present in-silico study provides a deeper insight into the structural attributes of 1d compound and its overall molecular interactions against SFRP4 and gives a hypothetical gateway to use this compound as a potential inhibitor against ovarian carcinoma.
Biased and less sensitive: A gamified approach to delay discounting in heroin addiction
Publisher: Informa UK Limited
Date: 09-05-2017
DOI: 10.1080/13803395.2017.1324022
Abstract: People with addiction will continue to use drugs despite adverse long-term consequences. We hypothesized (a) that this deficit persists during substitution treatment, and (b) that this deficit might be related not only to a desire for immediate gratification, but also to a lower sensitivity for optimal decision making. We investigated how in iduals with a history of heroin addiction perform (compared to healthy controls) in a virtual reality delay discounting task. This novel task adds to established measures of delay discounting an assessment of the optimality of decisions, especially in how far decisions are influenced by a general choice bias and/or a reduced sensitivity to the relative value of the two alternative rewards. We used this measure of optimality to apply diffusion model analysis to the behavioral data to analyze the interaction between decision optimality and reaction time. The addiction group consisted of 25 patients with a history of heroin dependency currently participating in a methadone maintenance program the control group consisted of 25 healthy participants with no history of substance abuse, who were recruited from the Western Sydney community. The patient group demonstrated greater levels of delay discounting compared to the control group, which is broadly in line with previous observations. Diffusion model analysis yielded a reduced sensitivity for the optimality of a decision in the patient group compared to the control group. This reduced sensitivity was reflected in lower rates of information accumulation and higher decision criteria. Increased discounting in in iduals with heroin addiction is related not only to a generally increased bias to immediate gratification, but also to reduced sensitivity for the optimality of a decision. This finding is in line with other findings about the sensitivity of addicts in distinguishing optimal from nonoptimal choice options.
When your face describes your memories: facial expressions during retrieval of autobiographical memories
Publisher: Walter de Gruyter GmbH
Date: 11-05-2018
DOI: 10.1515/REVNEURO-2018-0001
Abstract: Thanks to the current advances in the software analysis of facial expressions, there is a burgeoning interest in understanding emotional facial expressions observed during the retrieval of autobiographical memories. This review describes the research on facial expressions during autobiographical retrieval showing distinct emotional facial expressions according to the characteristics of retrieved memoires. More specifically, this research demonstrates that the retrieval of emotional memories can trigger corresponding emotional facial expressions (e.g. positive memories may trigger positive facial expressions). Also, this study demonstrates the variations of facial expressions according to specificity, self-relevance, or past versus future direction of memory construction. Besides linking research on facial expressions during autobiographical retrieval to cognitive and affective characteristics of autobiographical memory in general, this review positions this research within the broader context research on the physiologic characteristics of autobiographical retrieval. We also provide several perspectives for clinical studies to investigate facial expressions in populations with deficits in autobiographical memory (e.g. whether autobiographical overgenerality in neurologic and psychiatric populations may trigger few emotional facial expressions). In sum, this review paper demonstrates how the evaluation of facial expressions during autobiographical retrieval may help understand the functioning and dysfunctioning of autobiographical memory.
Changes in structural network topology correlate with severity of hallucinatory behaviour in Parkinson's disease
Publisher: Cold Spring Harbor Laboratory
Date: 03-08-2018
DOI: 10.1101/383141
Abstract: An inefficient integration between bottom-up visual input and higher-order visual processing regions is implicated in the manifestation of visual hallucinations (VH) in Parkinson’s disease (PD). Using graph theory, the current study aimed to investigate white matter contributions to this perceptual imbalance hypothesis. Twenty-nine PD patients reported their hallucinatory behaviour on a questionnaire and performed a behavioural test that has been shown to elicit misperceptions. A composite score derived from these measures was used as a proxy for hallucinations severity and was correlated to connectivity strength of the network using the Network Based Statistic approach. The results showed that the severity of VH was associated with reduced connectivity within a large sub-network. This network included the majority of the erse club and showed overall greater between - and within-module scores, compared to nodes not associated with hallucination severity. Furthermore, a reduction in between-module connectivity in the lateral occipital cortex, insula and pars orbitalis, as well as decreased within-module connectivity in the prefrontal, somatosensory and primary visual cortices were associated with VH severity. In contrast, the severity of VH was associated with an increase in between - and within-module connectivity in the orbitofrontal and temporal cortex, as well as regions comprising the dorsal attentional and DMN. These results suggest that the severity of VHs is associated with marked alterations in structural network topology, highlighted by a reduction in connectivity strength across a large sub-network, as well as changes in participation across top-down visual processing centres, visual and attentional networks. Therefore, impaired integration across the perceptual hierarchy may result in the inefficient transfer of information that gives rise to VHs in PD.
α-Synuclein gene duplication impairs reward learning
Publisher: Proceedings of the National Academy of Sciences
Date: 23-08-2010
Abstract: α-Synuclein (SNCA) plays an important role in the regulation of dopaminergic neurotransmission and neurodegeneration in Parkinson disease. We investigated reward and punishment learning in asymptomatic carriers of a rare SNCA gene duplication who were healthy siblings of patients with Parkinson disease. Results revealed that healthy SNCA duplication carriers displayed impaired reward and intact punishment learning compared with noncarriers. These results demonstrate that a copy number variation of the SNCA gene is associated with selective impairments on reinforcement learning in asymptomatic carriers without the motor symptoms of Parkinson disease.
Drinking motives as a predictor of readiness to change alcohol use
Publisher: Springer Science and Business Media LLC
Date: 21-02-2023
DOI: 10.1007/S12144-023-04245-5
Abstract: Drinking motives have been identified as important predictors of alcohol consumption. Similarly, the degree of readiness to change (RTC) can predict behavioral changes when drinking alcohol. However, the link between drinking motives and RTC has not been explored in previous research. The aim of this study is to investigate whether the four drinking motives (coping, enhancement, social, conformity) can predict the three stages of RTC (precontemplation, contemplation and action) in relation to alcohol consumption. Two hundred and fifty-two undergraduates’ students completed an online self-assessment survey on Qualtrics that assessed motives for alcohol use, drinking behavior, and RTC. Hierarchical regressions showed that among the four specific drinking motives, coping motives significantly predicted all three stages of RTC conformity motives positively predicted the action stage of change social motives negatively predicted the precontemplation and action stages of change enhancement motives were not significant in predicting RTC stages. These results indicate that the three RTC levels can be predicted by coping, social, and conformity motives, but not by enhancement motives. Additionally, given the importance of coping motives, it might be useful to address and include healthier coping mechanisms as part of clinical interventions and prevention methods to circumvent unsafe drinking behaviors independent of a single RTC stage.
The Influence of Divine Rewards and Punishments on Religious Prosociality
Publisher: Frontiers Media SA
Date: 03-08-2016
Modeling Serotonin’s Contributions to Basal Ganglia Dynamics in Parkinson’s Disease with Impulse Control Disorders
Publisher: Springer Singapore
Date: 2018
Future Thinking in Korsakoff Syndrome
Publisher: Oxford University Press (OUP)
Date: 02-05-2019
Abstract: Prior research has been mainly concerned with the ability of patients with Korsakoff syndrome (KS) to project themselves into the past. Little is known about the patients’ ability to project themselves into the future. We therefore compared past and future thinking in patients with KS. We invited patients with KS and control participants to retrieve past events and reconstruct future events. Participants were also invited to rate subjective characteristics (i.e. time travel, emotional feeling, and visual imagery) of the past and future events. Patients with KS demonstrated low specificity, time travel, and emotional experience during past and future thinking. However, while lower emotional experience was observed in patients with KS than in the control participants during future thinking, no significant differences were observed between the two populations during past thinking. Regarding within-group comparisons, patients with KS demonstrated no significant differences between past and future thinking in terms of specificity, time travel, and visual imagery however, they demonstrated higher emotional experience during past than during future thinking. Regarding control participants, they demonstrated no significant differences between past and future thinking in terms of specificity, time travel, emotional experience, and visual imagery. Our findings demonstrate a diminished ability to construct specific future scenarios as well as a diminished subjective experience during future thinking in KS.
Modeling Serotonin’s Contributions to Basal Ganglia Dynamics
Publisher: Springer Singapore
Date: 2018
Combined Computational Systems Biology and Computational Neuroscience Approaches Help Develop of Future “Cognitive Developmental Robotics”
Publisher: Frontiers Media SA
Date: 15-11-2017
Levodopa Enhances Reward Learning but Impairs Reversal Learning in Parkinson's Disease Patients
Publisher: Frontiers Media SA
Date: 2011
Brain N-Acetyl Aspartate and associations with cognitive impairment in alcohol dependent patients
Publisher: Informa UK Limited
Date: 07-11-2019
Toward a unified theory of childhood trauma and psychosis: A comprehensive review of epidemiological, clinical, neuropsychological and biological findings
Publisher: Elsevier BV
Date: 04-2017
DOI: 10.1016/J.NEUBIOREV.2017.02.015
Abstract: There is a growing body of research focused on the relationship between childhood trauma and the risk of developing psychosis. Numerous studies, including many large-scale population-based studies, controlling for possible mediating variables, provide persuasive evidence of a dose-response association and are indicative of a causal relationship. Existing evidence supports the specificity model, showing differential associations between particular adversities and clinical symptoms, with cumulative adversity causing less favorable clinical and functional outcomes in psychotic patients. To date, several psychological and biological models have been proposed to search for underlying developmental trajectories leading to the onset of psychosis, influencing psychopathological manifestation and negative functional outcomes due to a history of childhood trauma. In this article, we provide a unified review on the relationship between childhood trauma and psychosis by integrating results of epidemiological, clinical, neuropsychological and biological studies. The question whether psychosis with a positive history of childhood trauma should be considered as a new psychotic phenotype, requiring specific therapeutic interventions, warrants further investigation.
Singles and Faces: High Recognition for Female Faces in Single Males
Publisher: University of Economics and Human Sciences in Warsaw
Date: 12-2019
DOI: 10.5709/ACP-0277-X
Migration and sociodemographic factors associated with sense of place attitudes among migrants of African background in Northern and Western Netherlands.
Publisher: Wiley
Date: 24-08-2018
DOI: 10.1002/JCOP.22118
Dose-dependent neuroprotective effect of caffeine on a rotenone-induced rat model of parkinsonism: A histological study
Publisher: Elsevier BV
Date: 06-2016
DOI: 10.1016/J.NEULET.2016.04.057
Abstract: Several lines of evidence have demonstrated an inverse relationship between caffeine utilization and Parkinson's disease (PD) progression. Caffeine is a methylxanthine known as a non-specific inhibitor of adenosine (A2A and A1) receptors in the cerebrum and demonstrated to be a neuroprotective medication. In this study, the neuroprotective efficacy of two different doses of caffeine ranging above the usual consumption dose and below the toxic dose was investigated using histopathological and immunohistochemical methods. Thirty-two male rats were randomly ided into 4 groups, with 8 in each group: vehicle control (1ml/kg/48h for 12 days), rotenone (1.5mg/kg/48h, s.c. for 12 days), low-dose Caffeine-treated: (10mg/kg IP. daily for 12 days), high-dose Caffeine-treated (20mg IP daily for 12 days). Twenty-four hours after the last rotenone injection, animals were sacrificed and brains were sectioned and prepared for histopathological staining with hematoxylinand eosin, cresyl violet and Mallory's phosphotungestic acid haematoxylinand for immunohistochemical staining of tyrosine hydroxylase. Our study showed that the treatment with caffeine improved histopathological degeneration in the substantia nigra parts compacta (SNpc) neurons and hindered the reduction in dopamine concentration caused by rotenone. We also found that a higher dose of caffeine was more effective against histopathological degeneration. These results suggest that caffeine has a dose-dependent neuroprotective effect.
Visual imagery: The past and future as seen by patients with Alzheimer’s disease
Publisher: Elsevier BV
Date: 02-2019
DOI: 10.1016/J.CONCOG.2018.12.003
Abstract: We investigated visual imagery for past and future thinking in Alzheimer's Disease (AD). We invited AD patients and controls to retrieve past events and to imagine future events. Participants also provided a "Field" response if they see the event through their own eyes, or an "Observer" response if they see themselves in the scene as a spectator would. Less "Field" and more "Observer" responses were observed in AD participants than in controls during past and future thinking, suggesting a diminished ability to mentally visualize past and future events in AD. Results also demonstrated significant positive correlations between the production of "Field" responses and specificity during past and future thinking, suggesting a relationship between the ability to mentally visualize past and future events and autobiographical overgenerality in AD.
Homocysteine Levels in Neurological Disorders
Publisher: Wiley
Date: 06-02-2015
Depression impairs learning, whereas the selective serotonin reuptake inhibitor, paroxetine, impairs generalization in patients with major depressive disorder
Publisher: Elsevier BV
Date: 11-2013
Parcellating cognitive heterogeneity in early psychosis-spectrum illnesses: A cluster analysis
Publisher: Elsevier BV
Date: 12-2018
DOI: 10.1016/J.SCHRES.2018.06.060
Abstract: Cognitive impairment is argued to represent a core feature of psychosis-spectrum illnesses. However, within-diagnosis heterogeneity is common, and risk factors for poor cognition remain to be examined after statistically accounting for heterogeneity. Accordingly, we used a data-driven technique (cluster analysis) to empirically-derive cognitive clusters across diagnoses and examined whether concurrent substance use or a history of a neurodevelopmental/behavioral disorder differed between clusters. Data from 135 young help-seekers (aged 12-30 years) with a psychosis-spectrum illness were retrospectively analyzed. Ward's hierarchical cluster analysis classified three cognitive clusters characterized by: (1) normal-range (2) mixed and (3) grossly-impaired performance. Despite mostly comparable clinical and demographic measures, cluster 1 had superior socio-occupational functioning and the highest estimated premorbid IQ, followed sequentially by clusters 2 and 3. Proportions of cannabis and hetamine users did not differ significantly across clusters, nor did rates of patients with a neurodevelopmental/behavioral disorder history. Cluster 3 was however comprised of fewer 'risky' drinkers, possibly reflecting reduced opportunity for social drinking associated with cognitive impairment. Estimated premorbid IQ predicted cluster membership (2 vs. 1 & 3 vs. 1), as did clinician-rated socio-occupational functioning and 'not being enrolled in school or tertiary education' (3 vs. 1). Our results suggest that concurrent substance use and history of a neurodevelopmental/behavioral disorder do not adequately explain cluster-level cognitive variance in this s le. Future work should integrate neurobiological measures associated with cognition (e.g. white matter integrity) to discern whether clusters reflect neurobiological subtypes better representative of pathophysiology than present symptom-based classifications.
Smell your memories: Positive effect of odor exposure on recent and remote autobiographical memories in Alzheimer’s disease
Publisher: Informa UK Limited
Date: 19-03-2019
A dopaminergic basis for working memory, learning and attentional shifting in Parkinsonism
Publisher: Elsevier BV
Date: 11-2008
DOI: 10.1016/J.NEUROPSYCHOLOGIA.2008.07.011
Abstract: Parkinson's disease (PD) patients exhibit cognitive deficits, including reinforcement learning, working memory (WM) and set shifting. Computational models of the basal ganglia-frontal system posit similar mechanisms for these deficits in terms of reduced dynamic range of striatal dopamine (DA) signals in both medicated and non-medicated states. Here, we report results from the first study that tests PD patients on and off dopaminergic medications in a modified version of the AX continuous performance (AX-CPT) working memory task, consisting of three performance phases and one phase requiring WM associations to be learned via reinforcement feedback. Patients generally showed impairments relative to controls. Medicated patients showed deficits specifically when having to ignore distracting stimuli during the delay. Our models suggest that this impairment is due to medication causing excessive WM updating by enhancing striatal "Go" signals that facilitate such updating, while concurrently suppressing "NoGo" signals. In contrast, patients off medication showed deficits consistent with an overall reduction in striatal DA and associated Go updating signals. Supporting this dichotomy, patients on and off medication both showed attentional shifting deficits, but for different reasons. Deficits in non-medicated patients were consistent with an inability to update the new attentional set, whereas those in medicated patients were evident when having to ignore distractors that had previously been task relevant. Finally, in the feedback-based WM phase, medicated patients were better than unmedicated patients, suggesting a key role of striatal DA in using feedback to update information into WM. These results lend further insight into the role of basal ganglia dopamine in WM and broadly support predictions from neurocomputational models.
On and Off switches in the brain
Publisher: Frontiers Media SA
Date: 29-04-2015
Parkinson’s disease as a system-level disorder
Publisher: Springer Science and Business Media LLC
Date: 12-2016
Abstract: Traditionally, the basal ganglia have been considered the main brain region implicated in Parkinson’s disease. This single area perspective gives a restricted clinical picture and limits therapeutic approaches because it ignores the influence of altered interactions between the basal ganglia and other cerebral components on Parkinsonian symptoms. In particular, the basal ganglia work closely in concert with cortex and cerebellum to support motor and cognitive functions. This article proposes a theoretical framework for understanding Parkinson’s disease as caused by the dysfunction of the entire basal ganglia–cortex–cerebellum system rather than by the basal ganglia in isolation. In particular, building on recent evidence, we propose that the three key symptoms of tremor, freezing, and impairments in action sequencing may be explained by considering partially overlapping neural circuits including basal ganglia, cortical and cerebellar areas. Studying the involvement of this system in Parkinson’s disease is a crucial step for devising innovative therapeutic approaches targeting it rather than only the basal ganglia. Possible future therapies based on this different view of the disease are discussed.
A network model of basal ganglia for understanding the roles of dopamine and serotonin in reward-punishment-risk based decision making
Publisher: Frontiers Media SA
Date: 17-06-2015
The Personality Trait of Intolerance to Uncertainty Affects Behavior in a Novel Computer-Based Conditioned Place Preference Task
Publisher: Frontiers Media SA
Date: 09-08-2016
Cognitive Theory of Mind Influences Destination Memory: Evidence from Normal Aging and Alzheimer’s Disease
Publisher: Oxford University Press (OUP)
Date: 18-03-2019
Abstract: Theory of mind and destination memory are social abilities that require processing the attributes of interlocutors. Empirical research has demonstrated a relationship between performance on both abilities in normal aging and Alzheimer’s disease (AD). We therefore investigated whether processing attributes of interlocutors would result in better destination memory in AD. Twenty-six mild AD participants and 28 controls were tested on two occasions. On the first one, participants had to tell proverbs to celebrities’ faces. Following that, they decided whether they previously told that proverb to that celebrity or not. The same procedures were repeated on the second occasion however, after telling the proverbs, participants had to introspect about what the celebrities might think about the proverbs (e.g., “what do you think that the celebrities would think about the proverbs?”). Group comparisons showed a beneficial effect of introspection on destination memory in controls (Z = −2.57, p & .05) but not in AD participants (Z = −1.05, p = .29). However, analyzes of in idual profiles demonstrated that 15 AD participants demonstrated better destination memory after introspection. Our findings show a beneficial effect of introspection on destination memory in normal aging, and at least in some mild AD cases. Future research should investigate the influence of social cognition on memory in AD and how introspection may provide a potential treatment for AD.
Dysfunction in attentional processing in patients with Parkinson’s disease and visual hallucinations
Publisher: Springer Science and Business Media LLC
Date: 03-03-2016
DOI: 10.1007/S00702-016-1528-3
Abstract: Mechanistic insights into visual hallucinations (VH) in Parkinson's disease (PD) have suggested a role for impaired attentional processes. The current study tested 25 PD patients with and 28 PD patients without VH on the attentional network test. Hallucinators had significantly lower accuracy rates compared to non-hallucinators, but no differences were found in reaction times. This suggests that hallucinators show deficits in attentional processes and conflict monitoring. Our findings provide novel behavioural insights that dovetail with current neurobiological frameworks of VH.
The role of frontostriatal impairment in freezing of gait in Parkinson's disease
Publisher: Frontiers Media SA
Date: 2013
Impairments in reinforcement learning do not explain enhanced habit formation in cocaine use disorder
Publisher: Springer Science and Business Media LLC
Date: 08-2019
THE PREVALENCE OF PTSD AND DEPRESSION AMONG GAZA CHILDREN
Publisher: Maya Global Education Society
Date: 29-11-2019
Abstract: Purpose: The purpose of this study is to investigate the prevalence of posttraumatic distress disorder (PTSD) and depression among children in Gaza, Palestine. Methodology: This study assessed the psychological effects of the Israeli-Palestinian conflict on children in the Gaza Strip. 286 children aged 9-14 years old, who were exposed to a wide range of war events, were selected from the Gaza Strip to participate in this study. All participants conducted the following scales: the child PTSD Reaction Index(CPTSD-RI), Beck Depression Inventory (BDI), and the Arabic version for PTSD and depression assessment. Finding: The results show that the mean number of participants witnessing home destroyed and people killed was (88%) and home invasion (76%). Approximately 70% of the participants reported that they witnessed war violence against at least one of their family members. Further, 44 % of the children have a least one death in their family due to the Israeli invasion. Using t-tests, we found that significantly more females have both PTSD and depression than males. Approximately 32.8% of the participants met the criteria for severe depression, and 42.6 % met the criteria for PTSD. Implications: Our results suggest that it is imperative to provide intervention programs to treat PTSD and depression symptoms among children in Gaza. These programs should take into account the cultural and religious background of the participants. Originality: This investigation of the Israeli-Palestinian conflict has led to an increase in PTSD and depression symptoms among children in the Gaza Strip.
Cognitive function in schizophrenia: Conflicting findings and future directions
Publisher: Walter de Gruyter GmbH
Date: 06-2016
DOI: 10.1515/REVNEURO-2015-0060
Abstract: Introduction: Schizophrenia is a severe mental disorder with multiple psychopathological domains being affected. Several lines of evidence indicate that cognitive impairment serves as the key component of schizophrenia psychopathology. Although there have been a multitude of cognitive studies in schizophrenia, there are many conflicting results. We reasoned that this could be due to in idual differences among the patients (i.e. variation in the severity of positive vs. negative symptoms), different task designs, and/or the administration of different antipsychotics. Methods: We thus review existing data concentrating on these dimensions, specifically in relation to dopamine function. We focus on most commonly used cognitive domains: learning, working memory, and attention. Results: We found that the type of cognitive domain under investigation, medication state and type, and severity of positive and negative symptoms can explain the conflicting results in the literature. Conclusions: This review points to future studies investigating in idual differences among schizophrenia patients in order to reveal the exact relationship between cognitive function, clinical features, and antipsychotic treatment.
Intolerance of uncertainty in opioid dependency – Relationship with trait anxiety and impulsivity
Publisher: Public Library of Science (PLoS)
Date: 31-07-2017
The Basal Ganglia: Summary and Future Modeling Research
Publisher: Springer Singapore
Date: 2018
The effects of dynamical synapses on firing rate activity: a spiking neural network model
Publisher: Wiley
Date: 19-10-2017
DOI: 10.1111/EJN.13712
Abstract: Accumulating evidence relates the fine-tuning of synaptic maturation and regulation of neural network activity to several key factors, including GABA
The Swinging Self: The Costs of Shifting Between Self-Images in Alzheimer’s Disease
Publisher: SAGE Publications
Date: 2020
Abstract: We investigated the ability of patients with Alzheimer’s disease (AD) to shift between different self-images. We developed an original task (shifting-self task) in which we invited 28 patients with AD and 30 control participants to generate “who am I” statements that describe 2 alternative self-images (ie, physical-self vs psychological-self). In a control task, participants had to generate 2 blocks of “who am I” statements (ie, physical-self block and psychological-self block). Analyses showed longer completion time in both the shifting-self and control task in patients with AD than in control participants. Completion time on the shifting-self task was longer than that on the control task in patients with AD, suggesting a shifting cost in AD. We propose that one feature of the diminished sense of self in AD is the difficulty of patients to shift between different alternating self-images.
Molecular Docking and Dynamic Simulation of AZD3293 and Solanezumab Effects Against BACE1 to Treat Alzheimer's Disease
Publisher: Frontiers Media SA
Date: 06-2018
A computational model of pattern separation efficiency in the dentate gyrus with implications in schizophrenia
Publisher: Frontiers Media SA
Date: 25-03-2015
An Exergame Integrated with IoT to Support Remote Rehabilitation
Publisher: Springer International Publishing
Date: 14-12-2019
Intact goal-directed control in treatment-seeking drug users indexed by outcome-devaluation and Pavlovian to instrumental transfer: critique of habit theory
Publisher: Wiley
Date: 25-07-2019
DOI: 10.1111/EJN.13961
Abstract: Animal studies have demonstrated that chronic exposure to drugs of abuse impairs goal-directed control over action selection indexed by the outcome-devaluation and specific Pavlovian to instrumental transfer procedures, suggesting this impairment might underpin addiction. However, there is currently only weak evidence for impaired goal-directed control in human drug users. Two experiments were undertaken in which treatment-seeking drug users and non-matched normative reference s les (controls) completed outcome-devaluation and specific Pavlovian to instrumental transfer procedures notionally translatable to animal procedures (Experiment 2 used a more challenging biconditional schedule). The two experiments found significant outcome-devaluation and specific Pavlovian to instrumental transfer effects overall and there was no significant difference between groups in the magnitude of these effects. Moreover, Bayes factor supported the null hypothesis for these group comparisons. Although limited by non-matched group comparisons and small s le sizes, the two studies suggest that treatment-seeking drug users have intact goal-directed control over action selection, adding uncertainty to already mixed evidence concerning the role of habit learning in human drug dependence. Neuro-interventions might seek to tackle goal-directed drug-seeking rather than habit formation in drug users.
The discounted future: Relationship between temporal discounting and future thinking in Alzheimer’s disease
Publisher: No publisher found
Date: 2020
DOI: 10.1080/23279095.2020.1764958
Abstract: Temporal discounting refers to the tendency to prefer smaller sooner rewards over larger later rewards. Prior research has reported temporal discounting in Alzheimer's disease (AD). We thus investigated, in this study, the relationship between temporal discounting and future thinking in AD. The study included 40 patients with AD and 42 control participants. We invited participants, on a temporal discounting task, to choose between an immediate but smaller or a delayed but larger amount of money (e.g. "would you prefer 10 dollars today or 50 dollars after one month?"). We also invited the participants to imagine events that may happen in the future, a task known as future thinking. Analysis demonstrated a bias toward immediate rewards (i.e. temporal discounting) as well as difficulties to imagine specific future events in patients with AD. Critically, temporal discounting and future thinking in AD were significantly correlated. Generally speaking, a lack of thinking about the future may lead to impulsive behavior. More specifically, decline in future thinking in AD may limit the ability of patients to project themselves in time to consider outcomes of their decisions, resulting in a tendency to devaluate future rewards in favor of more imminent ones (i.e. temporal discounting).
A review on future episodic thinking in mood and anxiety disorders
Publisher: Walter de Gruyter GmbH
Date: 19-12-2018
DOI: 10.1515/REVNEURO-2017-0055
Abstract: Future episodic thinking refers to the ability to imagine oneself in the future and project oneself into specific future events. This cognitive process is related to decision making and planning for the future. Although healthy populations commonly project themselves into the future (e.g. while planning a trip or career), patients with mood disorders show impairment in this ability. In this review article, we discuss the similarities and differences in future thinking among the following populations: major depressive disorder, dysphoria, anxiety, and post-traumatic stress disorder (PTSD). Importantly, we highlight the methodological variations in future episodic memory tasks in the literature that may explain the differences in the existing results.
The image of memory: relationship between autobiographical memory and mental imagery in Korsakoff syndrome
Publisher: Informa UK Limited
Date: 29-01-2020
DOI: 10.1080/23279095.2020.1716759
Abstract: We evaluated the relationship between autobiographical memory and mental imagery in Korsakoff syndrome (KS). We invited patients with KS and control participants to retrieve personal events and to perform measures of visual imagery (Taller/Wilder task), and spatial imagery (Clock Angles task). On the Taller/Wilder task, participants had to generate a mental image of an object presented as a word and determine whether the object was taller than it was wide. On the Clock Angles task, participants had to imagine the angle created by the hands on a clock set to a certain time and determine whether that angle was <90°. Analyses showed impaired spatial imagery and autobiographical memory but intact visual imagery in KS. Analyses also demonstrated significant correlations between visual imagery, spatial imagery and autobiographical memory in patients with KS and control participants. Our findings demonstrate that autobiographical retrieval in KS is associated with the ability to retrieve (visual imagery) and manipulate mental images (spatial imagery).
Applications of machine learning to behavioral sciences: focus on categorical data
Publisher: Springer Science and Business Media LLC
Date: 15-03-2022
DOI: 10.1007/S44202-022-00027-5
Abstract: In the last two decades, advancements in artificial intelligence and data science have attracted researchers' attention to machine learning. Growing interests in applying machine learning algorithms can be observed in different scientific areas, including behavioral sciences. However, most of the research conducted in this area applied machine learning algorithms to imagining and physiological data such as EEG and fMRI and there are relatively limited non-imaging and non-physiological behavioral studies which have used machine learning to analyze their data. Therefore, in this perspective article, we aim to (1) provide a general understanding of models built for inference, models built for prediction (i.e., machine learning), methods used in these models, and their strengths and limitations (2) investigate the applications of machine learning to categorical data in behavioral sciences and (3) highlight the usefulness of applying machine learning algorithms to non-imaging and non-physiological data (e.g., clinical and categorical) data and provide evidence to encourage researchers to conduct further machine learning studies in behavioral and clinical sciences.
The Impact of Different Types of Abuse on Depression
Publisher: Hindawi Limited
Date: 13-04-2021
DOI: 10.1155/2021/6654503
Abstract: Despite a large amount of research on depression and abuse, there is still a controversy on how abuse is measured and on childhood trauma’s effect on the physiological function of adults. Here, we attempt to clarify the relationship between different types of abuse and depression while focusing on childhood abuse. This article, unlike prior research, provides an overview that addresses physical, psychological, and sexual abuse and their psychological impact on the victims. Results show that abuse is a vulnerability factor for a variety of mental and physical health problems and that psychological abuse is strongly associated with depression. More research is needed to understand (a) the role of abuse in the development and maintenance of depression and, in particular, longitudinal studies that also account for the large number of risk and protective factors that influence this relationship and (b) how different types of abuse can influence response to treatment among survivors with depression, in order to provide effective trauma-focused approaches to manage depressive symptoms.
Dynamic Communications Between GABAA Switch, Local Connectivity, and Synapses During Cortical Development: A Computational Study
Publisher: Frontiers Media SA
Date: 17-12-2018
The “authentic subjective experience” of memory in Alzheimer’s disease
Publisher: Walter de Gruyter GmbH
Date: 2020
Abstract: Most research has mainly focused on the decline of the subjective experience in Alzheimer’s disease (AD). However, few attempts have been made to evaluate whether subjective experience may be maintained in AD. In this narrative review, we attempt to provide a positive view, according to which patients with AD can enjoy, to some extent, subjective experience during memory retrieval. Memory and expression difficulties (e.g., aphasia) limit the ability of patients with AD to describe their memories, resulting in a little specificity of reported memories. However, according to the “authentic subjective experience” view, we propose in this study that the ability to mentally relive these memories could be preserved in the patients. By proposing the authentic subjective experience view, we attempt to provide an alternative view to the general consideration that the patients suffer a diminished subjective experience. This view can contribute to a larger clinical framework that gives a positive meaning to the subjective experience of patients with AD. Furthermore, several clinical and empirical implications can be drawn from the authentic subjective experience view, including the possibility to evaluate behavioral correlates of the subjective experience in AD.
Learning and generalization from reward and punishment in opioid addiction
Publisher: Elsevier BV
Date: 2017
Neural and behavioral substrates of subtypes of Parkinson’s disease
Publisher: Frontiers Media SA
Date: 2013
Mathematics anxiety and cognition: an integrated neural network model
Publisher: Walter de Gruyter GmbH
Date: 14-11-2019
DOI: 10.1515/REVNEURO-2019-0068
Abstract: Many students suffer from anxiety when performing numerical calculations. Mathematics anxiety is a condition that has a negative effect on educational outcomes and future employment prospects. While there are a multitude of behavioral studies on mathematics anxiety, its underlying cognitive and neural mechanism remain unclear. This article provides a systematic review of cognitive studies that investigated mathematics anxiety. As there are no prior neural network models of mathematics anxiety, this article discusses how previous neural network models of mathematical cognition could be adapted to simulate the neural and behavioral studies of mathematics anxiety. In other words, here we provide a novel integrative network theory on the links between mathematics anxiety, cognition, and brain substrates. This theoretical framework may explain the impact of mathematics anxiety on a range of cognitive and neuropsychological tests. Therefore, it could improve our understanding of the cognitive and neurological mechanisms underlying mathematics anxiety and also has important applications. Indeed, a better understanding of mathematics anxiety could inform more effective therapeutic techniques that in turn could lead to significant improvements in educational outcomes.
Homocysteine levels in schizophrenia and affective disorders—focus on cognition
Publisher: Frontiers Media SA
Date: 06-10-2014
Mindfulness and meditation: treating cognitive impairment and reducing stress in dementia
Publisher: Walter de Gruyter GmbH
Date: 21-02-2018
DOI: 10.1515/REVNEURO-2017-0066
Abstract: This study investigates the relationship between mindfulness, meditation, cognition and stress in people with Alzheimer’s disease (AD), dementia, mild cognitive impairment and subjective cognitive decline. Accordingly, we explore how the use of meditation as a behavioural intervention can reduce stress and enhance cognition, which in turn ameliorates some dementia symptoms. A narrative review of the literature was conducted with any studies using meditation as an intervention for dementia or dementia-related memory conditions meeting inclusion criteria. Studies where moving meditation was the main intervention were excluded due to the possible confounding of exercise. Ten papers were identified and reviewed. There was a broad use of measures across all studies, with cognitive assessment, quality of life and perceived stress being the most common. Three studies used functional magnetic resonance imaging to measure functional changes to brain regions during meditation. The interventions fell into the following three categories: mindfulness, most commonly mindfulness-based stress reduction (six studies) Kirtan Kriya meditation (three studies) and mindfulness-based Alzheimer’s stimulation (one study). Three of these studies were randomised controlled trials. All studies reported significant findings or trends towards significance in a broad range of measures, including a reduction of cognitive decline, reduction in perceived stress, increase in quality of life, as well as increases in functional connectivity, percent volume brain change and cerebral blood flow in areas of the cortex. Limitations and directions for future studies on meditation-based treatment for AD and stress management are suggested.
Motor and cognitive changes in normal aging
Publisher: Frontiers Media SA
Date: 25-11-2014
Using an animal learning model of the hippocampus to simulate human fMRI data
Publisher: IEEE
Date: 03-2010
Distress and sleep quality in young amphetamine-type stimulant users with an affective or psychotic illness
Publisher: Elsevier BV
Date: 04-2018
DOI: 10.1016/J.PSYCHRES.2018.02.033
Abstract: Misuse of hetamine-type stimulant (ATS) drugs may disrupt key neurodevelopmental processes in young people and confer protracted neurocognitive and psychopathological harm. ATS users with a co-occurring psychiatric illness are typically excluded from research, reducing generalisability of findings. Accordingly, we conducted a cross-sectional examination of key clinical, sleep, socio-occupational and neurocognitive measures in current, past and never users of ATS drugs who were accessing a youth mental health service (headspace) for affective- or psychotic-spectrum illnesses. Contrary to hypotheses, groups did not differ in psychotic symptomology, socio-occupational functioning or neurocognitive performance. Current ATS users were however significantly more distressed and reported poorer subjective sleep quality and greater subjective sleep disturbances than never users, with a trend toward greater depressive symptomology in current users. Regression analyses revealed that depressive symptoms, daily ATS use and socio-occupational functioning predicted distress, and depressive symptoms and distress predicted subjective sleep quality. Our findings suggest that distress and poor sleep quality reflect a particular pathophysiology among ATS-using patients, which may negatively impact treatment engagement. Delineating the factors that disrupt social and neurobiological development in young people (such as substance use) warrants further investigation, including longitudinal study.
Impaired neurogenesis of the dentate gyrus is associated with pattern separation deficits: A computational study
Publisher: World Scientific Pub Co Pte Lt
Date: 09-2016
Diffusion alterations associated with Parkinson's disease symptomatology: A review of the literature
Publisher: Elsevier BV
Date: 12-2016
DOI: 10.1016/J.PARKRELDIS.2016.09.026
Abstract: Parkinson's disease (PD) is a heterogeneous neurological disorder with a variety of motor and non-motor symptoms. The underlying mechanisms of these symptoms are not fully understood. An increased interest in structural connectivity analyses using diffusion tensor imaging (DTI) in PD has led to an expansion of our understanding of the impact of abnormalities in diffusivity on phenotype. This review outlines the contribution of these abnormalities to symptoms of PD including bradykinesia, tremor and non-tremor phenotypes, freezing of gait, cognitive impairment, mood, sleep disturbances, visual hallucinations and olfactory dysfunction. Studies have shown that impairments in cognitive functioning are related to diffusion abnormalities in frontal and parietal regions, as well as in the corpus callosum and major fibres connecting midbrain and subcortical structures with the neocortex. However, the impact of diffusion alterations on motor, mood and other symptoms of PD are less well understood. The findings presented here highlight the challenges faced and the potential areas of future research avenues where DTI may be beneficial. Larger cohort studies and standardized imaging protocols are required to investigate current promising preliminary findings.
Dopamine improves exploration after expectancy violations and induces psychotic-like experiences in patients with Parkinson’s disease
Publisher: Elsevier BV
Date: 03-2016
DOI: 10.1016/J.NEULET.2016.01.037
Abstract: Dopamine neurons are sensitive to novel and rewarding events, and dopamine signals can modulate learning in higher-level brain networks. Additionally, dopamine abnormalities appear to be central to the pathophysiology of schizophrenia spectrum disorders. In this study, we investigate the dopaminergic modulation of schizotypal traits and exploration after expectancy violations in Parkinson's disease (PD) patients on dopamine replacement therapy. Exploration after expectancy violations was measured with a latent inhibition and an anomaly categorisation task. Patients with PD had significantly elevated levels of schizotypy and reduced latent inhibition, relative to the controls. Anomaly categorisation was enhanced at trend level among the patients. Dopaminergic antiparkinsonian drugs showed dose-dependent effects: they induced psychotic-like experiences, and at the same time, they disrupted latent inhibition and made categorisation of anomaly more efficient. Most of these findings were replicated in an independent s le of patients with PD. An up-regulated dopamine system in medicated PD patients might tune higher-level brain networks to engage in learning when faced with unexpected information, and therefore hasten the updating of internal models.
Sparse and burst spiking in artificial neural networks inspired by synaptic retrograde signaling
Publisher: Elsevier BV
Date: 12-2017
Effects of antipsychotics on insight in schizophrenia
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 07-2016
Editorial: Schizophrenia: Human and Animal Studies
Publisher: Frontiers Media SA
Date: 20-04-2016
Identifying the Basal Ganglia Network Model Markers for Medication-Induced Impulsivity in Parkinson's Disease Patients
Publisher: Public Library of Science (PLoS)
Date: 04-06-2015
Reward and punishment learning in schizophrenia and bipolar disorder
Publisher: Elsevier BV
Date: 03-2020
DOI: 10.1016/J.BBR.2019.112298
Abstract: Prior studies on reward learning deficits in psychiatric disorders have used probabilistic learning tasks, making it unclear whether impairment is due to the probabilistic nature of the task rather than reward processing. In this study, we tested probabilistic vs. deterministic reward and punishment learning in healthy controls and three patient groups: schizophrenia (SZ), psychotic bipolar disorder (BD), and nonpsychotic BD. Experimental results show that reward learning was impaired in patients with SZ and patients with psychotic BD in the probabilistic learning task compared to patients with nonpsychotic BD and healthy controls. In contrast, punishment learning in the probabilistic task was impaired in patients with nonpsychotic BD compared to the other patient groups and healthy controls. There were no significant differences among all groups in the deterministic learning task scores. We also found that Hamilton Depression Scale scores negatively correlated with probabilistic learning performance. Our data may suggest that reward learning impairment may be due to the nature of the task as well as subtype of BD.
Treatment-resistant schizophrenia: focus on the transsulfuration pathway
Publisher: Walter de Gruyter GmbH
Date: 12-11-2019
DOI: 10.1515/REVNEURO-2019-0057
Abstract: Treatment-resistant schizophrenia (TRS) is a severe form of schizophrenia. The severity of illness is positively related to homocysteine levels, with high homocysteine levels due to the low activity of the transsulfuration pathway, which metabolizes homocysteine in synthesizing L-cysteine. Glutathione levels are low in schizophrenia, which indicates shortages of L-cysteine and low activity of the transsulfuration pathway. Hydrogen sulfide (H 2 S) levels are low in schizophrenia. H 2 S is synthesized by cystathionine β-synthase and cystathionine γ-lyase, which are the two enzymes in the transsulfuration pathway. Iron-sulfur proteins obtain sulfur from L-cysteine. The oxidative phosphorylation (OXPHOS) pathway has various iron-sulfur proteins. With low levels of L-cysteine, iron-sulfur cluster formation will be dysregulated leading to deficits in OXPHOS in schizophrenia. Molybdenum cofactor (MoCo) synthesis requires sulfur, which is obtained from L-cysteine. With low levels of MoCo synthesis, molybdenum-dependent sulfite oxidase (SUOX) will not be synthesized at appropriate levels. SUOX detoxifies sulfite from sulfur-containing amino acids. If sulfites are not detoxified, there can be sulfite toxicity. The transsulfuration pathway metabolizes selenomethionine, whereby selenium from selenomethionine can be used for selenoprotein synthesis. The low activity of the transsulfuration pathway decreases selenoprotein synthesis. Glutathione peroxidase (GPX), with various GPXs being selenoprotein, is low in schizophrenia. The dysregulations of selenoproteins would lead to oxidant stress, which would increase the methylation of genes and histones leading to epigenetic changes in TRS. An add-on treatment to mainline antipsychotics is proposed for TRS that targets the dysregulations of the transsulfuration pathway and the dysregulations of other pathways stemming from the transsulfuration pathway being dysregulated.
Toward a multiscale modeling framework for understanding serotonergic function
Publisher: SAGE Publications
Date: 18-04-2017
Genetic underpinnings in Alzheimer’s disease – a review
Publisher: Walter de Gruyter GmbH
Date: 20-12-2017
DOI: 10.1515/REVNEURO-2017-0036
Abstract: In this review, we discuss the genetic etiologies of Alzheimer’s disease (AD). Furthermore, we review genetic links to protein signaling pathways as novel pharmacological targets to treat AD. Moreover, we also discuss the clumps of AD-m ediated genes according to their single nucleotide polymorphism mutations. Rigorous data mining approaches justified the significant role of genes in AD prevalence. Pedigree analysis and twin studies suggest that genetic components are part of the etiology, rather than only being risk factors for AD. The first autosomal dominant mutation in the amyloid precursor protein ( APP ) gene was described in 1991. Later, AD was also associated with mutated early-onset (presenilin 1/2, PSEN1/2 and APP ) and late-onset (apolipoprotein E, ApoE ) genes. Genome-wide association and linkage analysis studies with identified multiple genomic areas have implications for the treatment of AD. We conclude this review with future directions and clinical implications of genetic research in AD.
Dissociating the Cognitive Effects of Levodopa versus Dopamine Agonists in a Neurocomputational Model of Learning in Parkinson’s Disease
Publisher: S. Karger AG
Date: 31-10-2012
DOI: 10.1159/000341999
Abstract: b i Background/Aims: /i /b Levodopa and dopamine agonists have different effects on the motor, cognitive, and psychiatric aspects of Parkinson’s disease (PD). b i Methods: /i /b Using a computational model of basal ganglia (BG) and prefrontal cortex (PFC) dopamine, we provide a theoretical synthesis of the dissociable effects of these dopaminergic medications on brain and cognition. Our model incorporates the findings that levodopa is converted by dopamine cells into dopamine, and thus activates prefrontal and striatal D sub /sub and D sub /sub dopamine receptors, whereas antiparkinsonian dopamine agonists directly stimulate D sub /sub receptors in the BG and PFC (although some have weak affinity to D sub /sub receptors). b i Results: /i /b In agreement with prior neuropsychological studies, our model explains how levodopa enhances, but dopamine agonists impair or have no effect on, stimulus-response learning and working memory. b i Conclusion: /i /b Our model explains how levodopa and dopamine agonists have differential effects on motor and cognitive processes in PD.
Computational analysis of histidine mutations on the structural stability of human tyrosinases leading to albinism insurgence
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7MB00211D
Abstract: Misfolding and structural alteration in proteins lead to serious malfunctions and cause various diseases in humans.
A spiking Basal Ganglia model of synchrony, exploration and decision making
Publisher: Frontiers Media SA
Date: 27-05-2015
Cognitive and social cognitive deficits in paranoia
Publisher: Elsevier
Date: 2019
Reward-learning and the novelty-seeking personality: a between- and within-subjects study of the effects of dopamine agonists on young Parkinson's patients
Publisher: Oxford University Press (OUP)
Date: 04-05-2009
DOI: 10.1093/BRAIN/AWP094
Differential functions of ventral and dorsal striatum
Publisher: Oxford University Press (OUP)
Date: 31-03-2015
DOI: 10.1093/BRAIN/AWV084
A commentary on: A 12-year population-based study of freezing of gait in Parkinson's disease
Publisher: Frontiers Media SA
Date: 02-06-2015
Factors underlying probabilistic and deterministic stimulus-response learning performance in medicated and unmedicated patients with Parkinson’s disease.
Publisher: American Psychological Association (APA)
Date: 2013
DOI: 10.1037/A0032757
Abstract: Prior studies have not tested in idual differences or effects of medication dosage on stimulus-response learning in patients with Parkinson's disease (PD). In the current study, we investigated the effects of motor variables (including tremor, akinesia, and disease duration) as well as dopaminergic medication dosage on learning in unmedicated PD patients, medicated PD patients, and healthy controls. We tested all subjects on probabilistic and deterministic learning tasks, and also collected awareness measures data using postexperimental questionnaires. Importantly, we tested learning performance in tremor-dominant and akinesia-dominant PD patients, and further correlated learning performance with disease duration and medication dosage. Results show that akinesia-dominant patients were more impaired than tremor-dominant patients at probabilistic reward- but not punishment-based learning, which is in agreement with prior studies of the relationship between akinesia and basal ganglia dysfunction. We also found no difference between medicated and unmedicated PD patients in reward- or punishment-based deterministic learning, but medicated patients were better than unmedicated patients at reward-based probabilistic learning. Our results show that awareness measures explain differences among probabilistic and deterministic learning performance. Moreover, we found that disease duration and motor severity are inversely correlated, and medication dosage is positively correlated, with reward-based probabilistic learning. Our results suggest that stimulus-response learning performance in patients with PD depends on the type of learning (probabilistic vs. deterministic), medication status (on vs. off medication, dopaminergic medication dosage), disease duration as well as motor severity and subtype in PD patients (tremor- vs. akinesia-dominant).
The dependence of neuronal encoding efficiency on Hebbian plasticity and homeostatic regulation of neurotransmitter release
Publisher: Frontiers Media SA
Date: 28-04-2015
Green model to adapt classical conditioning learning in the hippocampus
Publisher: Elsevier BV
Date: 02-2020
DOI: 10.1016/J.NEUROSCIENCE.2019.11.021
Abstract: Compared with the biological paradigms of classical conditioning, non-adaptive computational models are not capable of realistically simulating the biological behavioural functions of the hippoc al regions, because of their implausible requirement for a large number of learning trials, which can be on the order of hundreds. Additionally, these models did not attain a unified, final stable state even after hundreds of learning trials. Conversely, the output response has a different threshold for similar tasks in various models with prolonged transient response of unspecified status via the training or even testing phases. Accordingly, a green model is a combination of adaptive neuro-computational hippoc al and cortical models that is proposed by adaptively updating the whole weights in all layers for both intact networks and lesion networks using instar and outstar learning rules with adaptive resonance theory (ART). The green model sustains and expands the classical conditioning biological paradigms of the non-adaptive models. The model also overcomes the irregular output response behaviour by using the proposed feature of adaptivity. Further, the model successfully simulates the hippoc al regions without passing the final output response back to the whole network, which is considered to be biologically implausible. The results of the Green model showed a significant improvement confirmed by empirical studies of different tasks. In addition, the results indicated that the model outperforms the previously published models. All the obtained results successfully and quickly attained a stable, desired final state (with a unified concluding state of either "1" or "0") with a significantly shorter transient duration.
Exploring associations between early substance use and longitudinal socio-occupational functioning in young people engaged in a mental health service
Publisher: Public Library of Science (PLoS)
Date: 17-01-2019
Identifying the neural correlates of doorway freezing in Parkinson's disease
Publisher: Wiley
Date: 13-01-2019
DOI: 10.1002/HBM.24506
Towards Proactive Web Service Adaptation
Publisher: Springer International Publishing
Date: 2012
A disease-modifying treatment for Alzheimer’s disease: focus on the trans-sulfuration pathway
Publisher: Walter de Gruyter GmbH
Date: 21-11-2019
DOI: 10.1515/REVNEURO-2019-0076
Abstract: High homocysteine levels in Alzheimer’s disease (AD) result from low activity of the trans-sulfuration pathway. Glutathione levels are also low in AD. L-cysteine is required for the synthesis of glutathione. The synthesis of coenzyme A (CoA) requires L-cysteine, which is synthesized via the trans-sulfuration pathway. CoA is required for the synthesis of acetylcholine and appropriate cholinergic neurotransmission. L-cysteine is required for the synthesis of molybdenum-containing proteins. Sulfite oxidase (SUOX), which is a molybdenum-containing protein, could be dysregulated in AD. SUOX detoxifies the sulfites. Glutaminergic neurotransmission could be dysregulated in AD due to low levels of SUOX and high levels of sulfites. L-cysteine provides sulfur for iron-sulfur clusters. Oxidative phosphorylation (OXPHOS) is heavily dependent on iron-sulfur proteins. The decrease in OXPHOS seen in AD could be due to dysregulations of the trans-sulfuration pathway. There is a decrease in aconitase 1 (ACO1) in AD. ACO1 is an iron-sulfur enzyme in the citric acid cycle that upon loss of an iron-sulfur cluster converts to iron regulatory protein 1 (IRP1). With the dysregulation of iron-sulfur cluster formation ACO1 will convert to IRP1 which will decrease the 2-oxglutarate synthesis dysregulating the citric acid cycle and also dysregulating iron metabolism. Selenomethionine is also metabolized by the trans-sulfuration pathway. With the low activity of the trans-sulfuration pathway in AD selenoproteins will be dysregulated in AD. Dysregulation of selenoproteins could lead to oxidant stress in AD. In this article, we propose a novel treatment for AD that addresses dysregulations resulting from low activity of the trans-sulfuration pathway and low L-cysteine.
Impaired Specificity of Future Thinking in Alcohol Use Disorders
Publisher: Wiley
Date: 19-03-2019
DOI: 10.1111/ACER.13993
Abstract: While there has been a body of work that has investigated past thinking in in iduals with alcohol use disorders (AUD), little is known about future thinking in these in iduals. We invited participants with AUD and control participants to construct past and future events. We have also investigated the relationship between constructing past and future events and depression. By analyzing the specificity (i.e., the ability in constructing specific events situated in time and space) of these events, results demonstrated lower specificity of past and future thinking in AUD participants compared to control participants. No significant differences were observed between the specificity of past and future thinking in AUD or in control participants. Further, significant negative correlations were observed between depression and past/future thinking in AUD participants but not in controls. Difficulties in constructing specific future scenarios, as observed in AUD participants compared with controls, are presumably related to ruminative thinking and emotional avoidance aspects of depression, which should be investigated in future studies. More specifically, in iduals with AUD may tend to construct general future scenarios to dwell on negative past events and/or to avoid coping with hopelessness and processing of upsetting or distressful future scenarios.
Depression Following Major Life Transitions in Women: A Review and Theory
Publisher: SAGE Publications
Date: 30-08-2019
Abstract: Depression can occur due to common major life transitions, such as giving birth, menopause, retirement, empty-nest transition, and midlife crisis. Although some of these transitions are perceived as positive (e.g., giving birth), they may still lead to depression. We conducted a systematic literature review of the factors underlying the occurrence of depression following major life transition in some in iduals. This review shows that major common life transitions can cause depression if they are sudden, major, and lead to loss (or change) of life roles (e.g., no longer doing motherly or fatherly chores after children leave family home). Accordingly, we provide a theoretical framework that explains depression caused by transitions in women. One of the most potential therapeutic methods of ameliorating depression associated with life transitions is either helping in iduals accept their new roles (e.g., accepting new role as a mother to ameliorate postpartum depression symptoms) or providing them with novel life roles (e.g., volunteering after retirement or children leave family home) may help them overcome their illness.
Computational modeling and biomarker studies of pharmacological treatment of Alzheimer's disease (Review)
Publisher: Spandidos Publications
Date: 22-05-2018
Depression Impairs Learning Whereas Anticholinergics Impair Transfer Generalization in Parkinson Patients Tested on Dopaminergic Medications
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2010
Motor symptoms in Parkinson’s disease: A unified framework
Publisher: Elsevier BV
Date: 09-2016
DOI: 10.1016/J.NEUBIOREV.2016.07.010
Abstract: Parkinson's disease (PD) is characterized by a range of motor symptoms. Besides the cardinal symptoms (akinesia and bradykinesia, tremor and rigidity), PD patients show additional motor deficits, including: gait disturbance, impaired handwriting, grip force and speech deficits, among others. Some of these motor symptoms (e.g., deficits of gait, speech, and handwriting) have similar clinical profiles, neural substrates, and respond similarly to dopaminergic medication and deep brain stimulation (DBS). Here, we provide an extensive review of the clinical characteristics and neural substrates of each of these motor symptoms, to highlight precisely how PD and its medical and surgical treatments impact motor symptoms. In conclusion, we offer a unified framework for understanding the range of motor symptoms in PD. We argue that various motor symptoms in PD reflect dysfunction of neural structures responsible for action selection, motor sequencing, and coordination and execution of movement.
Impairments of working memory in schizophrenia and bipolar disorder: the effect of history of psychotic symptoms and different aspects of cognitive task demands
Publisher: Frontiers Media SA
Date: 28-11-2014
The subjective experience of mind wandering in Alzheimer’s disease
Publisher: Informa UK Limited
Date: 03-02-2020
Holistic Management of Schizophrenia Symptoms Using Pharmacological and Non-pharmacological Treatment
Publisher: Frontiers Media SA
Date: 07-06-2018
Coping styles and symptomatic manifestation of first-episode psychosis: Focus on cognitive performance
Publisher: Elsevier BV
Date: 02-2019
DOI: 10.1016/J.PSYCHRES.2018.12.083
Abstract: Cognitive deficits are widely observed in patients with psychosis and represent one of most important determinants of functional outcomes. It has been shown that patients with psychosis prefer maladaptive coping strategies over active coping styles. However, it remains unknown whether cognitive impairments are related to coping styles in psychotic disorders. Therefore, the aim of this study was to assess whether cognitive deficits observed in patients with first-episode psychosis (FEP) might impact the use of specific coping strategies. We recruited 40 FEP patients and 35 healthy controls. In our study, FEP patients were more likely to use maladaptive coping styles after adjustment for education level and medication effects. The use of maladaptive coping strategies was associated with greater impairments of visuospatial/constructional abilities and language skills in FEP patients. In addition, lower odds of using adaptive coping were related to higher levels of depressive symptoms in the group of patients. Adaptive coping was associated with better global cognitive performance in healthy controls. Our results indicate that cognitive impairments, especially worse performance of visuospatial/constructional abilities and language skills, might be related to the preference of maladaptive coping strategies. Lower odds of using adaptive coping styles might be associated with more severe depressive symptomatology.
The many facets of dopamine: Toward an integrative theory of the role of dopamine in managing the body's energy resources
Publisher: Elsevier BV
Date: 10-2018
DOI: 10.1016/J.PHYSBEH.2018.06.032
Abstract: In neuroscience literature, dopamine is often considered as a pleasure chemical of the brain. Dopaminergic neurons respond to rewarding stimuli which include primary rewards like opioids or food, or more abstract forms of reward like cash rewards or pictures of pretty faces. It is this reward-related aspect of dopamine, particularly its association with reward prediction error, that is highlighted by a large class of computational models of dopamine signaling. Dopamine is also a neuromodulator, controlling synaptic plasticity in several cortical and subcortical areas. But dopamine's influence is not limited to the nervous system its effects are also found in other physiological systems, particularly the circulatory system. Importantly, dopamine agonists have been used as a drug to control blood pressure. Is there a theoretical, conceptual connection that reconciles dopamine's effects in the nervous system with those in the circulatory system? This perspective article integrates the erse physiological roles of dopamine and provides a simple theoretical framework arguing that its reward related function regulates the processes of energy consumption and acquisition in the body. We conclude by suggesting that energy-related book-keeping of the body at the physiological level is the common motif that links the many facets of dopamine and its functions.
Interactions between cannabis and schizophrenia in humans and rodents
Publisher: Walter de Gruyter GmbH
Date: 2017
DOI: 10.1515/REVNEURO-2016-0083
Abstract: In this review, we provide an overview of the relationship between cannabis use and the development of schizophrenia, using both animal and human studies. We further discuss the potential neural mechanism that may mediate the relationship between cannabis use and schizophrenia symptoms. We finally provide clinical implications and future studies that can further elucidate the relationship between cannabis and schizophrenia.
A computational model of conditioning inspired by Drosophila olfactory system
Publisher: Elsevier BV
Date: 03-2017
DOI: 10.1016/J.NEUNET.2016.11.002
Abstract: Recent studies have demonstrated that Drosophila melanogaster (briefly Drosophila) can successfully perform higher cognitive processes including second order olfactory conditioning. Understanding the neural mechanism of this behavior can help neuroscientists to unravel the principles of information processing in complex neural systems (e.g. the human brain) and to create efficient and robust robotic systems. In this work, we have developed a biologically-inspired spiking neural network which is able to execute both first and second order conditioning. Experimental studies demonstrated that volume signaling (e.g. by the gaseous transmitter nitric oxide) contributes to memory formation in vertebrates and invertebrates including insects. Based on the existing knowledge of odor encoding in Drosophila, the role of retrograde signaling in memory function, and the integration of synaptic and non-synaptic neural signaling, a neural system is implemented as Simulated fly. Simulated fly navigates in a two-dimensional environment in which it receives odors and electric shocks as sensory stimuli. The model suggests some experimental research on retrograde signaling to investigate neural mechanisms of conditioning in insects and other animals. Moreover, it illustrates a simple strategy to implement higher cognitive capabilities in machines including robots.
Exploring the mechanistic insights of Cas scaffolding protein family member 4 with protein tyrosine kinase 2 in Alzheimer’s disease by evaluating protein interactions through molecular docking and dyn
Publisher: Springer Science and Business Media LLC
Date: 22-05-2018
DOI: 10.1007/S10072-018-3430-2
Abstract: Cas scaffolding protein family member 4 and protein tyrosine kinase 2 are signaling proteins, which are involved in neuritic plaques burden, neurofibrillary tangles, and disruption of synaptic connections in Alzheimer's disease. In the current study, a computational approach was employed to explore the active binding sites of Cas scaffolding protein family member 4 and protein tyrosine kinase 2 proteins and their significant role in the activation of downstream signaling pathways. Sequential and structural analyses were performed on Cas scaffolding protein family member 4 and protein tyrosine kinase 2 to identify their core active binding sites. Molecular docking servers were used to predict the common interacting residues in both Cas scaffolding protein family member 4 and protein tyrosine kinase 2 and their involvement in Alzheimer's disease-mediated pathways. Furthermore, the results from molecular dynamic simulation experiment show the stability of targeted proteins. In addition, the generated root mean square deviations and fluctuations, solvent-accessible surface area, and gyration graphs also depict their backbone stability and compactness, respectively. A better understanding of CAS and their interconnected protein signaling cascade may help provide a treatment for Alzheimer's disease. Further, Cas scaffolding protein family member 4 could be used as a novel target for the treatment of Alzheimer's disease by inhibiting the protein tyrosine kinase 2 pathway.
Reading Direction Influences Lateral Biases in Letter Processing
Publisher: American Psychological Association (APA)
Date: 10-2018
DOI: 10.1037/XLM0000540
Abstract: Humans have a limited capacity to identify concurrent, briefly presented targets. Recent experiments using concurrent rapid serial visual presentation of letters in horizontally displaced streams have documented a deficit specific to the stream in the right visual field. The cause of this deficit might be either prioritization of the left item based on participants' experience reading from left to right, or a right-hemisphere advantage specific to dual stimulation. Here we test the reading-experience hypothesis by using participants who have experience reading both a language written left-to-right (English) and one written right-to-left (Arabic). When tested with English letters, these participants showed a deficit, of a similar magnitude to that found previously, for reporting the item on the right. However, when the stimuli were Arabic letters the deficit was absent. This suggests that reading direction plays a large role in the second-target deficit. The pattern of participants' errors suggests where in the processing stream reading experience affects stimulus processing: Specifically, the error pattern suggests that the limited-capacity stage responsible for the deficit corresponds to a posts ling process such as consolidation into short-term memory. (PsycINFO Database Record (c) 2018 APA, all rights reserved).
Factors underlying cognitive decline in old age and Alzheimer's disease: The role of the hippocampus
Publisher: Walter de Gruyter GmbH
Date: 26-10-2017
DOI: 10.1515/REVNEURO-2016-0086
Abstract: There are many factors that strongly influence the aetiology, development, and progression of cognitive decline in old age, mild cognitive impairment (MCI), and Alzheimer’s disease (AD). These factors include not only different personality traits and moods but also lifestyle patterns (e.g. exercise and diet) and awareness levels that lead to cognitive decline in old age. In this review, we discuss how personality traits, mood states, and lifestyle impact brain and behaviour in older adults. Specifically, our review shows that these lifestyle and personality factors affect several brain regions, including the hippoc us, a region key for memory that is affected by cognitive decline in old age as well as AD. Accordingly, appropriate recommendations are presented in this review to assist in iduals in decreasing chances of MCI, dementia, AD, and associated symptoms.
The interactive effect of valence and context on reversal learning in individuals with Parkinson’s disease
Publisher: Elsevier BV
Date: 2019
DOI: 10.1016/J.NEULET.2018.11.006
Abstract: Cognitive deficits in Parkinson's disease (PD) have increasingly been recognized over the last decade and reversal learning in particular has received a great deal of attention. In a classical reversal-learning paradigm, participants learn to associate various stimuli with specific responses (i.e. A →Positive B→ Negative), and subsequently learn to associate the same stimuli with opposite outcomes (i.e., A→Negative B→ Positive). Prior studies have revealed that medicated PD patients have a selective impairment with learning from negative, but not positive, outcomes, even when both reward- and punishment-related stimuli were equally relevant. The aim of the present study was to further understand this impairment by applying a novel reversal-learning paradigm, which enables the differentiation between positive/negative and cue/context reversal impairments. Twenty-seven medicated PD patients and twenty-nine healthy in iduals matched for age, gender and education completed the cue-context reversal learning paradigm. The results revealed no significant differences in context reversal learning between in iduals with PD and healthy controls. However, in cue reversal learning, healthy controls were significantly better at performing positive-to-negative reversal trials compared to in iduals with PD, while in iduals with PD were significantly better in negative-to-positive reversal trials compared to healthy controls. As such, the present study distinguishes between different types of reversal learning and suggests that different neural circuits are responsible for context and cue learning. These results improve our understanding of the possible effects of dopaminergic medications and may have important clinical implications.
Increased hippocampal volume and gene expression following cognitive behavioral therapy in PTSD
Publisher: Frontiers Media SA
Date: 2013
Human appetitive Pavlovian-to-instrumental transfer: a goal-directed account
Publisher: Springer Science and Business Media LLC
Date: 13-11-2019
DOI: 10.1007/S00426-019-01266-3
Abstract: Pavlovian-to-instrumental transfer (PIT) tasks assess the impact of environmental stimuli on instrumental actions. Since their initial translation from animal to human experiments, PIT tasks have provided insight into the mechanisms that underlie reward-based behaviour. This review first examines the main types of PIT tasks used in humans. We then seek to contribute to the current debate as to whether human PIT effects reflect a controlled, goal-directed process, or a more automatic, non-goal-directed mechanism. We argue that the data favour a goal-directed process. The extent to which the major theories of PIT can account for these data is then explored. We discuss a number of associative accounts of PIT as well as dual-process versions of these theories. Ultimately, however, we favour a propositional account, in which human PIT effects are suggested to be driven by both perceived outcome availability and outcome value. In the final section of the review, we present the potential objections to the propositional approach that we anticipate from advocates of associative link theories and our response to them. We also identify areas for future research.
Adenosine A2A Receptor Blockade Prevents Rotenone-Induced Motor Impairment in a Rat Model of Parkinsonism
Publisher: Frontiers Media SA
Date: 29-02-2016
Corrigendum to: Genetic underpinnings in Alzheimer’s disease – a review
Publisher: Walter de Gruyter GmbH
Date: 09-2018
A neurocomputational model of classical conditioning phenomena: A putative role for the hippocampal region in associative learning
Publisher: Elsevier BV
Date: 06-2009
DOI: 10.1016/J.BRAINRES.2009.04.020
Abstract: Some existing models of hippoc al function simulate performance in classical conditioning tasks using the error backpropagation algorithm to guide learning (Gluck, M.A., and Myers, C.E., (1993). Hippoc al mediation of stimulus representation: a computational theory. Hippoc us, 3(4), 491-516.). This algorithm is not biologically plausible because it requires information to be passed backward through layers of nodes and assumes that the environment provides information to the brain about what correct outputs should be. Here, we show that the same information-processing function proposed for the hippoc al region in the Gluck and Myers (1993) model can also be implemented in a network without using the backpropagation algorithm. Instead, our newer instantiation of the theory uses only (a) Hebbian learning methods which match more closely with synaptic and associative learning mechanisms ascribed to the hippoc al region and (b) a more plausible representation of input stimuli. We demonstrate here that this new more biologically plausible model is able to simulate various behavioral effects, including latent inhibition, acquired equivalence, sensory preconditioning, negative patterning, and context shift effects. In addition, the newer model is able to address some new phenomena including the effect of the number of training trials on blocking and overshadowing.
Tell about yourself to improve your autobiographical memory: A study of Korsakoff's syndrome
Publisher: Elsevier BV
Date: 10-2018
DOI: 10.1016/J.PSYCHRES.2018.06.064
Abstract: Korsakoff's syndrome (KS) has been associated with a difficulty to retrieve specific autobiographical memories. We investigated whether this difficulty can be alleviated after the retrieval of statements describing self-images. KS patients and control participants were recruited and asked to retrieve autobiographical memories after providing statements to the question "Who am I?" and after a control condition consisting of verbal fluency. Analysis showed higher autobiographical specificity in the "Who am I?" than in verbal fluency condition in both patients with KS and control participants. At a theoretical level, our findings demonstrate how retrieval of information related to conceptual self may influence autobiographical memory in KS. At a clinical level, our procedures are important as they demonstrate how a simple task (i.e., "Who am I?" statements) may serve as a tool to cue specific autobiographical memories in patients with KS.
General functioning predicts reward and punishment learning in schizophrenia
Publisher: Elsevier BV
Date: 04-2011
DOI: 10.1016/J.SCHRES.2010.07.028
Abstract: Previous studies investigating feedback-driven reinforcement learning in patients with schizophrenia have provided mixed results. In this study, we explored the clinical predictors of reward and punishment learning using a probabilistic classification learning task. Patients with schizophrenia (n=40) performed similarly to healthy controls (n=30) on the classification learning task. However, more severe negative and general symptoms were associated with lower reward-learning performance, whereas poorer general psychosocial functioning was correlated with both lower reward- and punishment-learning performances. Multiple linear regression analyses indicated that general psychosocial functioning was the only significant predictor of reinforcement learning performance when education, antipsychotic dose, and positive, negative and general symptoms were included in the analysis. These results suggest a close relationship between reinforcement learning and general psychosocial functioning in schizophrenia.
Trust and trustworthiness in young and older adults.
Publisher: American Psychological Association (APA)
Date: 2015
DOI: 10.1037/A0039736
Abstract: In a series of 1-shot economic trust games in which participants could make real monetary profits, but also risked losing money, 2 studies compared young and older adults' trust (amount invested with trustees) and trustworthiness (amount returned to investors by trustees). In Study 1, young (n = 35) and older (n = 32) participants acted as investors, and the age of simulated trustees (young, older) was manipulated. In Study 2, young (n = 61) and older (n = 67) participants acted in real life as both investors and trustees. They completed 2 face-to-face trust games with same- and other-age partners, and 3 anonymous trust games with same-, other-, and unknown-age partners. Study 1 found that young and older participants rate older trustees as appearing more trustworthy than young trustees, but neither group invest more with older than young trustees. Rather, older participants were more likely than young participants to invest money averaged across trustee age. In Study 2, there were no age-related differences in trust, but older adults were more trustworthy than young adults in anonymous games with same- and unknown-age partners. It was also found that young adults demonstrate greater reputational concerns than older adults by reciprocating more trust when face-to-face than anonymous. We discuss the complex influences of age on trust game investing and reciprocation, as well as the implications for older adults' wellbeing and financial security.
A model of reversal learning and working memory in medicated and unmedicated patients with Parkinson’s disease
Publisher: Elsevier BV
Date: 04-2014
Drift diffusion model of reward and punishment learning in rare alpha-synuclein gene carriers
Publisher: Informa UK Limited
Date: 20-03-2017
DOI: 10.1080/01677063.2017.1301939
Abstract: To understand the cognitive effects of alpha-synuclein polymorphism, we employed a drift diffusion model (DDM) to analyze reward- and punishment-guided probabilistic learning task data of participants with the rare alpha-synuclein gene duplication and age- and education-matched controls. Overall, the DDM analysis showed that, relative to controls, asymptomatic alpha-synuclein gene duplication carriers had significantly increased learning from negative feedback, while they tended to show impaired learning from positive feedback. No significant differences were found in response caution, response bias, or motor/encoding time. We here discuss the implications of these computational findings to the understanding of the neural mechanism of alpha-synuclein gene duplication.
Social decision making in autism: On the impact of mirror neurons, motor control, and imitative behaviors
Publisher: Wiley
Date: 02-07-2018
DOI: 10.1111/CNS.13001
Mechanisms of disordered neurodegenerative function: concepts and facts about the different roles of the protein kinase RNA-like endoplasmic reticulum kinase (PERK)
Publisher: Walter de Gruyter GmbH
Date: 27-06-2018
DOI: 10.1515/REVNEURO-2017-0071
Abstract: Neurodegenerative diseases, such as Alzheimer’s disease, Huntington’s disease, Parkinson’s disease, prion disease, and amyotrophic lateral sclerosis, are a dissimilar group of disorders that share a hallmark feature of accumulation of abnormal intraneuronal or extraneuronal misfolded/unfolded protein and are classified as protein misfolding disorders. Cellular and endoplasmic reticulum (ER) stress activates multiple signaling cascades of the unfolded protein response (UPR). Consequently, translational and transcriptional alterations in target gene expression occur in response directed toward restoring the ER capacity of proteostasis and reestablishing the cellular homeostasis. Evidences from in vitro and in vivo disease models indicate that disruption of ER homeostasis causes abnormal protein aggregation that leads to synaptic and neuronal dysfunction. However, the exact mechanism by which it contributes to disease progression and pathophysiological changes remains vague. Downstream signaling pathways of UPR are fully integrated, yet with erse unexpected outcomes in different disease models. Three well-identified ER stress sensors have been implicated in UPR, namely, inositol requiring enzyme 1, protein kinase RNA-activated-like ER kinase (PERK), and activating transcription factor 6. Although it cannot be denied that each of the involved stress sensor initiates a distinct downstream signaling pathway, it becomes increasingly clear that shared pathways are crucial in determining whether or not the UPR will guide the cells toward adaptive prosurvival or proapoptotic responses. We review a body of work on the mechanism of neurodegenerative diseases based on oxidative stress and cell death pathways with emphasis on the role of PERK.
Osteoporosis and the effect of dysregulation of the transsulfuration pathway via taurine on intracellular calcium homeostasis, vitamin D absorption and vitamin K absorption
Publisher: Elsevier BV
Date: 06-2021
The Molecular, Cellular, and Systems-Level Structure of the Basal Ganglia
Publisher: Springer Singapore
Date: 2018
Visual Hallucinations Are Characterized by Impaired Sensory Evidence Accumulation: Insights From Hierarchical Drift Diffusion Modeling in Parkinson’s Disease
Publisher: Elsevier BV
Date: 11-2017
DOI: 10.1016/J.BPSC.2017.04.007
Abstract: Models of hallucinations emphasize imbalance between sensory input and top-down influences over perception, as false perceptual inference can arise when top-down predictions are afforded too much precision (certainty) relative to sensory evidence. Visual hallucinations in Parkinson's disease (PD) are associated with lower-level visual and attentional impairments, accompanied by overactivity in higher-order association brain networks. PD therefore provides an attractive framework to explore contributions of bottom-up versus top-down disturbances in hallucinations. We characterized sensory processing during perceptual decision making in patients with PD with (n = 20) and without (n = 25) visual hallucinations and control subjects (n = 12), by fitting a hierarchical drift diffusion model to an attentional task. The hierarchical drift diffusion model uses Bayesian estimates to decompose task performance into parameters reflecting drift rates of evidence accumulation, decision thresholds, and nondecision time. We observed slower drift rates in patients with hallucinations, which were less sensitive to changes in task demand. In contrast, wider decision boundaries and shorter nondecision times relative to control subjects were found in patients with PD regardless of hallucinator status. Inefficient and less flexible sensory evidence accumulation emerges as a unique feature of PD hallucinators. We integrate these results with evidence accumulation and predictive coding models of hallucinations, suggesting that in PD sensory evidence is less informative and may therefore be down-weighted, resulting in overreliance on top-down influences. Considering impaired drift rates as an approximation of reduced sensory precision, our findings provide a novel computational framework to specify impairments in sensory processing that contribute to development of visual hallucinations.
Reduced CA2–CA3 Hippocampal Subfield Volume Is Related to Depression and Normalized by l-DOPA in Newly Diagnosed Parkinson’s Disease
Publisher: Frontiers Media SA
Date: 03-0008
The Motor, Cognitive, Affective, and Autonomic Functions of the Basal Ganglia
Publisher: Springer Singapore
Date: 2018
Classical Computational Approaches to Modeling the Basal Ganglia
Publisher: Springer Singapore
Date: 2018
Genetic triple dissociation reveals multiple roles for dopamine in reinforcement learning
Publisher: Proceedings of the National Academy of Sciences
Date: 09-10-2007
Abstract: What are the genetic and neural components that support adaptive learning from positive and negative outcomes? Here, we show with genetic analyses that three independent dopaminergic mechanisms contribute to reward and avoidance learning in humans. A polymorphism in the DARPP-32 gene, associated with striatal dopamine function, predicted relatively better probabilistic reward learning. Conversely, the C957T polymorphism of the DRD2 gene, associated with striatal D2 receptor function, predicted the degree to which participants learned to avoid choices that had been probabilistically associated with negative outcomes. The Val/Met polymorphism of the COMT gene, associated with prefrontal cortical dopamine function, predicted participants' ability to rapidly adapt behavior on a trial-to-trial basis. These findings support a neurocomputational dissociation between striatal and prefrontal dopaminergic mechanisms in reinforcement learning. Computational maximum likelihood analyses reveal independent gene effects on three reinforcement learning parameters that can explain the observed dissociations.
A Deep Reinforcement Learning Approach for Large-Scale Service Composition
Publisher: Springer International Publishing
Date: 2018
A Basal Ganglia Model of Freezing of Gait in Parkinson’s Disease
Publisher: Springer Singapore
Date: 2018
Mental health and urban design – zoning in on PTSD
Publisher: Springer Science and Business Media LLC
Date: 30-11-2017
Learning Efficient Compositions for QoS-Aware Service Provisioning
Publisher: IEEE
Date: 06-2014
DOI: 10.1109/ICWS.2014.37
Assessment of the frequency criterion for the diagnosis of non-suicidal self-injury disorder in female adolescents with conduct disorder
Publisher: Elsevier BV
Date: 09-2018
DOI: 10.1016/J.PSYCHRES.2018.05.054
Abstract: Recent studies suggest a higher threshold number of self-injuries during the past year than the one proposed in the DSM-5 criteria for non-suicidal self-injury disorder (NSSID). Therefore, we aimed to test a validity of the frequency criterion in girls with conduct disorder (CD) based on psychopathology and the level of functioning. Mixture modelling analysis revealed that the frequency of at least 8 self-harm behaviours in the previous year differentiated adolescents with CD. Thus, we ided adolescents into three subgroups: group 1: at least 8 self-harm acts group 2: 1-7 self-harm behaviours and group 3: those who did not injure themselves during the last 12 months. In iduals from group 1 were significantly younger and had earlier age of self-harm onset. There were significant differences between groups 1 and 3 in terms of anxiety and depressive symptoms, self-esteem, aggression and the global functioning level. The group 1 scored significantly higher on depressive symptoms compared to the group 2. The group 2 scored significantly higher than the group 3 on the level of hostility. Our results provide further evidence supporting the need for modification of the NSSID frequency criterion.
Adenosine role in brain functions: Pathophysiological influence on Parkinson's disease and other brain disorders
Publisher: Springer Science and Business Media LLC
Date: 08-2018
DOI: 10.1016/J.PHAREP.2018.02.003
Abstract: Although adenosine plays a key role in multiple motor, affective, and cognitive processes, it has received less attention in the neuroscience field compared to other neurotransmitters (e.g., dopamine). In this review, we highlight the role of adenosine in behavior as well as its interaction with other neurotransmitters, such as dopamine. We also discuss brain disorders impacted by alterations to adenosine, and how targeting adenosine can ameliorate Parkinson's disease motor symptoms. We also discuss the role of caffeine (as an adenosine antagonist) on cognition as well as a neuroprotective agent against Parkinson's disease (PD).
Persistent irregular activity is a result of rebound and coincident detection mechanisms: A computational study
Publisher: Elsevier BV
Date: 06-2017
DOI: 10.1016/J.NEUNET.2017.03.007
Abstract: Persistent irregular activity is defined as elevated irregular neural discharges in the brain in such a way that while the average network activity displays high frequency oscillations, the participating neurons display irregular and low frequency oscillations. This type of activity is observed in many brain regions like prefrontal cortex that plays a role in working memory. Previous studies have shown that large networks with sparse connections, networks with strong noise and persistent inhibition and networks with structured synaptic connections display persistent-irregular activity. However, experimental studies show that, not all brain regions obey these assumptions. In this study we show that a small network of excitatory-inhibitory neurons with random synaptic connections can reproduce persistent-irregular activity. In particular, the model shows that less than perfect rebound pattern in excitatory cells, coincident-sensitive inhibitory cells and sparse synaptic inhibition can account for persistent-irregular activity in an excitatory-inhibitory neural network with randomly assigned synaptic connections.
Stigmergic Modeling for Web Service Composition and Adaptation
Publisher: Springer Berlin Heidelberg
Date: 2012
Probabilistic reward- and punishment-based learning in opioid addiction: Experimental and computational data
Publisher: Elsevier BV
Date: 2016
Learning from negative feedback in patients with major depressive disorder is attenuated by SSRI antidepressants
Publisher: Frontiers Media SA
Date: 2013
Between God and self: exploring the attachment to God and authenticity/inauthenticity tendencies of South African Christian youths
Publisher: Informa UK Limited
Date: 07-02-2017
Generalized Anxiety Disorder and Social Anxiety Disorder, but Not Panic Anxiety Disorder, Are Associated with Higher Sensitivity to Learning from Negative Feedback: Behavioral and Computational Invest
Publisher: Frontiers Media SA
Date: 29-06-2016
Mindfulness and Suicide Ideation in Iranian Cardiovascular Patients: Testing the Mediating Role of Patience
Publisher: SAGE Publications
Date: 07-12-2017
Abstract: The aim of the present study was to explore the mediating role of patience on the relationship between mindfulness and suicide ideation. To do so, 110 patients with cardiovascular diseases were recruited from the outpatient Clinic of Imam Reza in the city of Shiraz in Iran. These patients completed The Five Facets Mindfulness Questionnaire, Patience Scale, and Suicide Ideation Questionnaire. Data were analyzed using structural equation modeling. Results indicated a significant positive relationship between mindfulness and patience ( r = .32, p .001). There was a significant negative relationship between patience and suicide ideation ( r = −.36, p .001). The results of mediating model showed that patience functioned as a mediator in the relationship between mindfulness and suicide ideation among patients with cardiovascular diseases ( β = −.33, p = .005). According to these findings, it can be claimed that mindfulness affects patients’ suicidal thoughts negatively through patience.
Why trace and delay conditioning are sometimes (but not always) hippocampal dependent: A computational model
Publisher: Elsevier BV
Date: 02-2013
A meta-analysis study on peer influence and adolescent substance use
Publisher: Springer Science and Business Media LLC
Date: 18-07-2023
DOI: 10.1007/S12144-023-04944-Z
Abstract: The extent to which adolescents are influenced by their peers has been the focus of developmental psychological research for over 50 years. That research has yielded contradicting evidence and much debate. This study consists of a systematic review and meta-analysis, with the main aim of quantifying the effect of peer influence on adolescent substance use, as well as investigation into the factors that moderate this effect. Included studies needed to employ longitudinal designs, provide the necessary statistics to calculate cross-lagged regression coefficients controlling for target adolescent’s initial substance use, and comprise participants aged 10–19 years. A search of academic databases and reference lists generated 508 unique reports, which were screened using Covidence. The final inclusion criteria yielded a total of 99 effect sizes from 27 independent studies. A four-level meta-analytic approach with correction to allow the inclusion of multiple effect sizes from a given study was used to estimate an average effect size. Results revealed a significant effect of peer influence ( $$\\overline{\\upbeta }$$ β ¯ = .147, p .001), indicating that adolescents changed their substance use behaviour in accordance with their peers’ perceived or actual use. Moderation analyses found peer influence effects varied significantly as a function of substance use behaviour (categorised as alcohol, tobacco, marijuana, or composite substance use) and peer influence measure (perceived vs. actual peer report) however, no significant effects emerged in the multivariate moderation model simultaneously examining all five main moderators. These results suggest that adolescent substance use is affected by peer influence processes across multiple substance use behaviours and both directly and indirectly through perceived norms. This has significant implications for substance use prevention, including the potential of harnessing peer influence as a positive force and the need to target misperceptions of substance use.
Freezing of gait and response conflict in Parkinson's disease: Computational directions
Publisher: No publisher found
Date: 2014
“To whom did I tell that information?”: Relationship between destination memory and theory of mind in traumatic brain injury
Publisher: Informa UK Limited
Date: 19-03-2019
DOI: 10.1080/23279095.2019.1585350
Abstract: Traumatic Brain Injury (TBI) has been widely associated with impairment of social cognition. We therefore investigated the relationship between the ability to infer and predict other's mental states (i.e., Theory of Mind, ToM) and the ability to remember to whom one has sent information (i.e., destination memory). We invited patients with TBI and control subjects, on a destination memory task, to tell proverbs to pictures of celebrities, so as to remember to which celebrity they had previously told the proverbs. Participants also performed affective (i.e., Reading the Mind in the Eyes) and cognitive (i.e., the false belief) tests of ToM. Results demonstrated lower destination memory, affective, and cognitive ToM performance in TBI patients than in control subjects. Critically, analysis demonstrated significant positive correlations between destination memory and first order and second cognitive order ToM in patients with TBI, but no significant correlations between destination memory and affective ToM in these patients. Our results demonstrate a relationship between difficulties of TBI patients to infer and predict cognitive states of interlocutors and difficulties to remember to which interlocutor information has been told.
Cognitive emotion regulation strategies, anxiety, and depression in mothers of children with or without neurodevelopmental disorders
Publisher: Elsevier BV
Date: 08-2020
Probability discounting of monetary gains and losses in opioid-dependent adults
Publisher: Elsevier BV
Date: 05-2019
DOI: 10.1016/J.BBR.2019.02.017
Abstract: While the link between delay discounting and drug addiction has been well established, much less is known about probability discounting (PD) in the context of substance abuse. This study is the first to investigate how opioid-dependent in iduals make risky decisions about gains and losses using the PD paradigm. Fifty-six opioid-dependent adults receiving opioid maintenance therapy and 55 controls performed two tasks that assessed PD of hypothetical monetary gains and losses, and completed the Barratt Impulsivity Scale (BIS-11). Patient participants exhibited greater PD for gains than did controls, suggesting that patients were more risk-averse when considering potential rewards. Patients also demonstrated greater PD for losses, indicating that patients made riskier decisions to avoid a loss compared to controls. BIS-11 scores were not significantly associated with either discounting parameter, and PD of gains and losses were not meaningfully correlated. The results provide initial evidence that in iduals addicted to illicit substances discount probabilistic losses and gains differently than non-drug abusing cohorts, and in a way that maps onto drug taking behaviour. This pattern of discounting has implications for substance abuse treatments that target problematic risk taking.
The Relationship between Associative Learning, Transfer Generalization, and Homocysteine Levels in Mild Cognitive Impairment
Publisher: Public Library of Science (PLoS)
Date: 28-09-2012
Related Organisations
Related Funding Activities
Discovery Projects - Grant ID: DP190103600
Start Date: 2019
End Date: 12-2023
Amount: $443,000.00
Funder: Australian Research Council
View Funded ActivityDiscovery Projects - Grant ID: DP200100876
Start Date: 2020
End Date: 03-2024
Amount: $271,370.00
Funder: Australian Research Council
View Funded Activity