ORCID Profile
0000-0001-7266-0786
Current Organisation
Northumbria University
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Publisher: Elsevier BV
Date: 2014
DOI: 10.1016/J.PSCYCHRESNS.2013.10.006
Abstract: Diffusion tensor imaging (DTI) studies have identified changes in white matter tracts in schizophrenia patients and those at high risk of transition. Schizotypal s les represent a group on the schizophrenia continuum that share some aetiological risk factors but without the confounds of illness. The aim of the current study was to compare tract microstructural coherence as measured by fractional anisotropy (FA) between 12 psychometrically defined schizotypes and controls. We investigated bilaterally the uncinate and arcuate fasciculi (UF and AF) via a probabilistic tractography algorithm (PICo), with FA values compared between groups. Partial correlations were also examined between measures of subclinical hallucinatory/delusional experiences and FA values. Participants with schizotypal features were found to have increased FA values in the left hemisphere UF only. In the whole s le there was a positive correlation between FA values and measures of hallucinatory experience in the right AF. These findings suggest subtle changes in microstructural coherence are found in in iduals with schizotypal features, but are not similar to changes predominantly observed in clinical s les. Correlations between mild hallucinatory experience and FA values could indicate increasing tract coherence could be associated with symptom formation.
Publisher: Oxford University Press (OUP)
Date: 28-09-2006
Publisher: Wiley
Date: 17-03-2022
DOI: 10.1002/PCHJ.537
Publisher: Springer Science and Business Media LLC
Date: 17-10-2012
Publisher: Wiley
Date: 12-03-2020
DOI: 10.1002/PCHJ.353
Publisher: Wiley
Date: 17-12-2020
DOI: 10.1002/PCHJ.331
Abstract: Investigating the relationship between anticipatory pleasure deficits and risk features of mental disorders not only theoretically benefits the understanding of anhedonia, but could also facilitate early detection and intervention of mental disorders. Using network analysis, the present study examined the pattern of relationship between anticipatory pleasure and risk features of schizophrenia spectrum, depressive, anxiety, autism spectrum, and obsessive-compulsive disorders in a large s le of college students (n = 2152). It was found that interpersonal features of schizotypal personality traits and poor social skills of autistic traits showed strong correlation with low social anticipatory pleasure. Depressive symptoms severity was weakly associated with reduced abstract anticipatory pleasure, while obsessive-compulsive traits were weakly associated with high contextual anticipatory pleasure. No significant correlation was found between anxiety symptoms severity and anticipatory pleasure. Social anticipatory pleasure had the highest strength centrality among all anticipatory pleasure components, while interpersonal features of schizotypal personality traits had the highest strength centrality in the whole network. Our findings suggest that impaired anticipatory pleasure, especially social anticipatory pleasure, is a particular feature of schizotypal personality traits and autistic traits. Our findings may have implications for intervention in that the social component may be a target to improve anhedonia in in iduals with schizotypal and autistic traits, while interpersonal features may be a key treatment target given that it was central to the relationship between anticipatory pleasure and risk features.
Publisher: Wiley
Date: 07-11-2021
DOI: 10.1002/PCHJ.496
Abstract: Abnormalities in language processing, psychological distress, and subtle neurodevelopmental features called neurological soft signs (NSS) are expressed by people with dyslexia and those scoring highly on schizotypy. We investigated whether the expression of NSS, distress, and schizotypy predicted dyslexia status. Participants ( N = 96, 48 dyslexic) selected to be age and sex matched, completed the Schizotypal Personality Questionnaire, General Health Questionnaire, Neurological Evaluation Scale, and the National Adult Reading Test (NART a measure of verbal intelligence). Dyslexia status was predicted by higher total NSS and disorganized schizotypy scores in the absence of NART. However, even with the inclusion of NART, disorganized schizotypy remained a significant predictor. The findings suggest that disorganized features of schizotypy could be a significant factor for those with dyslexia. Conversely, more attention needs to be given to developmental language disorders in those who score highly on schizotypy.
Publisher: Wiley
Date: 29-04-2022
DOI: 10.1002/PCHJ.452
Abstract: Learning from feedback is essential for daily functioning, with factors that impact learning having implications for healthy and clinical populations. Reinforcement learning appears impaired across the psychosis continuum, with deficits reported in patients with psychotic disorders as well as high schizotypes from the general population. Stress can impair learning, and sensitivity to stress is present along the psychosis continuum. The aim of the present study was to understand if stress impairs reinforcement learning in those at the lower end of the psychosis continuum. We investigated both naturalistic stress in everyday life using daily hassles (Study 1: n = 70 31% male, M age = 22.67 years) and acute psychosocial stress using the Trier Social Stress Test (Study 2: n = 57 32% male, M age = 22.43 years). In the presence of naturalistic stress, learning did not differ across schizotypes. However, under acute psychosocial stress, high schizotypes experienced impaired learning. Our results suggest trail‐and‐error learning is robust to the ebbs and flows of everyday stress for high schizotypes however, acute stress is associated with decrements in learning. This indicates that the magnitude of stressors should be considered when designing cognitive and functional interventions for those along the psychosis continuum.
Publisher: Springer Science and Business Media LLC
Date: 30-07-2021
DOI: 10.1007/S40473-021-00232-X
Abstract: Anhedonia is a transdiagnostic symptom comprising reduced subjective reward or pleasure. Anhedonia influences subjective anticipation and in-the-moment experiences. This review draws together affective learning and engagement evidence for anhedonia affecting subjective experiences of social environments. While social engagement is diminished consistently, subjective appraisals of social contexts vary across different mental health disorders. Low positive affect during social experiences or stimuli is reported in PTSD, mood, schizophrenia, and anxiety disorders. Diminished neural reward networks underpin the anticipation of social experiences in ADHD, schizophrenia spectrum, and autistic spectrum disorders. Multiple theories exist to explain how anhedonia might interfere with social environments. Anhedonia is a barrier to engagement, motivation, and enjoyment of social contexts. While many studies characterize experiences during social contexts, learning theories provide the most promise for developing targeted interventions.
Publisher: Annual Reviews
Date: 03-2010
DOI: 10.1146/ANNUREV.CLINPSY.121208.131220
Abstract: Adolescence is a time of exploration of the self, and this exploration may involve the use of alcohol and drugs. Sadly, for some, adolescence also marks the first signs of a psychosis. The temporal proximity between the onset of substance use and of psychosis has been the cause of much debate. Here we review the association of alcohol, cannabis, stimulants, and other drugs with psychosis, and we conclude that the use of cannabis and the hetamines significantly contributes to the risk of psychosis.
Publisher: Frontiers Media SA
Date: 2013
Publisher: Informa UK Limited
Date: 02-03-2015
Publisher: Elsevier BV
Date: 06-2007
DOI: 10.1016/J.BRAT.2006.06.003
Abstract: Disordered or maladaptive meta-cognitive processing appears to be a prominent feature for some in iduals with a diagnosis of schizophrenia. We sought to establish whether healthy in iduals distinguished either in terms hallucination proneness (HP) or level of schizotypy could also be differentiated on the sub-scales of the Meta-cognitions Questionnaire (MCQ), or a modified version of it in which items about worry were replaced with items specifically related to thinking. A total of 106 healthy volunteers completed the Oxford and Liverpool Inventory of Feelings and Experiences and Launay-Slade hallucination scale, the Schizotypal Personality Questionnaire and two versions of the MCQ: the original which assesses five domains of meta-cognition and an adapted version in which items relating to worry had been replaced by items relating to thinking or reflecting on thinking (MCQ-th). ANOVA indicated highly significant differences between three groups of in iduals differentiated in terms of high, medium and low proneness to hallucinations on four of the five MCQ sub-scales, and three of the four MCQ-th factors. Regression analyses indicated that the MCQ factors encompassing (1) a sense of uncontrollability of thinking (and the perceived attendant dangers of this) and (2) negative beliefs about thinking related to suspicion and punishment were the strongest predictors of high schizotypy. In iduals who score higher on a measure of HP are more likely to display patterns of meta-cognitive processing that resemble, in certain respects, those reported in in iduals with a diagnosis of schizophrenia. High schizotypy predicts a negative appraisal about both the controllability and consequences of thinking.
Publisher: Routledge
Date: 05-06-2015
Publisher: Springer Science and Business Media LLC
Date: 23-01-2013
Publisher: SAGE Publications
Date: 09-2011
Abstract: Antipsychotic drugs are the mainstay of treatment for schizophrenia but they have little effect on core negative symptoms or cognitive impairment. To meet the deficiencies of current treatments, novel potential compounds are emerging from preclinical research but translation to clinical success has been poor. This article evaluates the possibility that cognitive and physiological abnormalities in schizophrenia can be used as central nervous system biomarkers to predict, in healthy volunteers, the likely efficacy of entirely new pharmacological approaches to treatment. Early detection of efficacy would focus resource on rapidly developing, effective drugs. We review the relevance of selected cognitive and physiological abnormalities as biomarkers in schizophrenia and three of its surrogate populations: (i) healthy volunteers with high trait schizotypy (ii) unaffected relatives of patients and (iii) healthy volunteers in a state of cortical glutamate disinhibition induced by low-dose ketamine. Several biomarkers are abnormal in these groups and in some instances there has been exploratory work to determine their sensitivity to drug action. They are generally insensitive to current antipsychotics and therefore their predictive validity cannot be established until novel, therapeutically useful drugs are discovered. Until then such biomarker studies can provide evidence of drugs engaging with the mechanism of interest and encouragement of the concept.
Publisher: Wiley
Date: 17-01-2022
DOI: 10.1002/PCHJ.508
Abstract: It is important for positive well‐being and social engagement to understand how people predict future emotions, an ability known as affective forecasting. However, mechanisms underpinning the change to affective forecasting are not well understood in people with subclinical psychiatric symptoms. The current study differentiated components that comprise affective forecasting and investigated how non‐clinical features relate to these. We recruited 319 participants to complete the social affective forecasting task and respond to questionnaires that captured schizotypal and autistic traits as well as depressive symptoms. Associations between affective forecasting and subclinical features were investigated using correlations, regression, and structure equation modeling. Results showed that interpersonal features of schizotypal traits negatively predicted anticipated emotions in positive social conditions via in‐the‐moment feelings but not via mental simulation. Findings highlight that in‐the‐moment feelings may be an intervention target to help people who have difficulties with social interactions to anticipate more pleasure for future social events.
Publisher: Elsevier BV
Date: 04-2016
DOI: 10.1016/J.NEUBIOREV.2016.01.010
Abstract: Cognitive failures are minor errors in thinking reported by clinical and non-clinical in iduals during everyday life. It is not yet clear how subjectively-reported cognitive failures relate to objective neuropsychological ability. We aimed to consolidate the definition of cognitive failures, outline evidence for the relationship with objective cognition, and develop a unified model of factors that increase cognitive failures. We conducted a systematic review of cognitive failures, identifying 45 articles according to the PRISMA statement. Failures were defined as reflecting proneness to errors in 'real world' planned thought and action. Vulnerability to failures was not consistently associated with objective cognitive performance. A range of stable and variable factors were linked to increased risk of cognitive failures. We conclude that cognitive failures measure real world cognitive capacity rather than pure 'unchallenged' ability. Momentary state may interact with predisposing trait factors to increase the likelihood of failures occurring. Inclusion of self-reported cognitive failures in objective cognitive research will increase the translational relevance of ability into more ecologically valid aspects of real world functioning.
Publisher: Wiley
Date: 15-02-2022
DOI: 10.1002/PCHJ.528
Abstract: Cognitive interpretations of daily events may differ in people from the general population who hold unusual beliefs. It is also important to understand whether different belief profiles exist to appreciate which patterns of beliefs are less psychologically healthy. Cluster analysis was used to form unusual belief profiles in a general population s le ( n = 578 M age = 22 years, SD = 6.98 80% female) across paranoid, paranormal, and magical ideation beliefs, and we assessed whether they differed in attribution style and metacognitive beliefs about worry. Four clusters were formed: low on all measures (low all) high on all measures (high all) comparably higher on paranormal beliefs (paranormal group) and comparably higher on paranoid beliefs (paranoid group). For total Metacognitions Questionnaire‐30, the high all and high paranoid clusters did not differ, and both clusters scored higher than the high paranormal group, who all scored higher than the low all cluster. For attributional styles (Attributional Styles Questionnaire), lower scores on internal positive attribution were found for the high all and high paranoid clusters compared to the low all and high paranormal clusters. The high paranormal cluster had higher scores than the high paranoid cluster on self‐serving bias. Differences in attributional style appeared to be driven by mental health diagnosis. Our results suggest different profiles of unusual beliefs are detectable in the general population that differ in their metacognitive beliefs and perceived causation of events in their environment. Future studies investigating delusional proneness need to consider multiple unusual beliefs as well as assessing mood state and distress.
Publisher: Cambridge University Press (CUP)
Date: 21-01-2008
DOI: 10.1017/S0033291707002619
Abstract: The relationship between cannabis use and psychosis is still a matter for debate. Accounting for the in idual differences in subjective experiences to recreational cannabis use in the general population may hold some clues to the aetiological relationship between cannabis and psychotic symptoms. We hypothesized that schizotypy would account for the in idual differences in subjective experiences after cannabis use but not in patterns of use. In a s le of 532 young people who had used cannabis at least once, we examined the relationship between the Cannabis Experiences Questionnaire (CEQ) and the Schizotypal Personality Questionnaire (SPQ). Additionally, we examined the psychometric properties of the CEQ. We replicated our previously reported findings that schizotypy was associated with increased psychosis-like experiences and after-effects, but also found that high-scoring schizotypes reported more pleasurable experiences when smoking cannabis. Using new subscales derived from principal components analysis (PCA), we found that the psychosis-like items were most related to varying rates of schizotypy both during the immediate use of cannabis and in the after-effects of cannabis use. High-scoring schizotypes who used cannabis experienced more psychosis-like symptoms during and after use. Our results suggest that cannabis use may reveal an underlying vulnerability to psychosis in those with high schizotypal traits.
Publisher: S. Karger AG
Date: 2006
DOI: 10.1159/000092678
Abstract: i Objective: /i Recent studies have suggested that cannabis use is a risk factor for developing schizophrenia. We tested the hypothesis that cannabis use increases the likelihood of psychosis-like experiences in non-clinical participants who scored highly on a measure of schizotypy. i Method: /i The psychological effects of cannabis were assessed in 137 healthy in iduals (76% female, mean age 22 years) using a newly developed questionnaire concerned with subjective experiences of the drug: the Cannabis Experiences Questionnaire. The questionnaire has three subscales: Pleasurable Experiences, Psychosis-Like Experiences and After-Effects. Respondents also completed the brief Schizotypal Personality Questionnaire. i Results: /i Cannabis use was reported by 72% of the s le. Use per se was not significantly related to schizotypy. However, high scoring schizotypes were more likely to report both psychosis-like experiences and unpleasant after-effects associated with cannabis use. The pleasurable effects of cannabis use were not related to schizotypy score. i Conclusion: /i High scoring schizotypes who use cannabis are more likely to experience psychosis-like phenomena at the time of use, and unpleasant after-effects. Our results are consistent with the hypothesis that cannabis use is a risk factor for full psychosis in this group.
Publisher: Elsevier BV
Date: 07-2012
DOI: 10.1016/J.EURONEURO.2011.10.005
Abstract: A number of compounds aimed at improving cognition in schizophrenia have failed to demonstrate efficacy in Phase 2 clinical trials. Translational studies using biomarkers in surrogate populations, such as schizotypy, could be used to assess the efficacy of novel compounds. In this study, we aimed to validate the sensitivity and inter-site reliability of cognitive biomarkers (working memory (N-back), spatial working memory (SWM) and verbal fluency (VF) tasks) to detect the schizotypy phenotype and its reversal by psychotropic drugs. Healthy volunteers scoring high or average on a schizotypal personality measure (122 in each group) were randomized to receive a single dose of risperidone, amisulpride, nicotine or placebo in a double-blind, between-subject design. We found evidence for a poorer performance on N-back and VF tasks in the high schizotypy group, replicating previous research. This effect was counteracted by amisulpride on N-back: it improved working memory in high schizotypy group but impaired the controls. A similar pattern was seen in SWM and VF. We interpret this finding in the light of the dopamine enhancing action of amisulpride when given in low doses. In contrast, risperidone impaired both groups and nicotine had a beneficial effect for the low baseline performers only. These effects were consistent across sites. These data demonstrates the utility of biomarkers in detecting the effect of schizotypy and its reversal by drugs that enhance dopamine and cholinergic function. Studies using similar design could help the early assessment of potential of compounds designed to improve cognition in schizophrenia.
Publisher: Wiley
Date: 21-01-2020
DOI: 10.1002/PCHJ.344
Abstract: Social anhedonia is associated with reduced social functioning and diminished reward from social interactions. In iduals expressing social anhedonia are likely to experience reduced social connectedness and feel lonely. Loneliness is also associated with reduced social functioning. Therefore, loneliness could account for the relationship between social anhedonia and social functioning. We aimed to determine whether loneliness mediates the relationship between social anhedonia and reduced social functioning. In total, 824 young adults (M age = 21.03, SD = 5.59 72.3% female) completed the Revised-Social Anhedonia Scale (RSAS), University of California Los Angeles (UCLA) Loneliness Scale, and the Social Functioning Scale (SFS). Scores on thee SFS were summed into six subscales: Social Withdrawal, Relationships, Social Activities, Recreational Activities, Independence (Competence), and Independence (Performance). Negative affect (Depression, Anxiety and Stress Scales-21 [DASS] total score) was included as a covariate. Both the RSAS and the UCLA Loneliness Scale were negatively correlated with overall and all social functioning subscales. The DASS-21 positively correlated with all variables of interest. Mediation analyses revealed that loneliness partially mediated the relationship between social anhedonia and the social functioning subscales, with the exception of Recreational Activities. However, loneliness was a full mediator for the relationship between social anhedonia and overall social functioning. The study findings suggest that targeting loneliness in interventions may be important for improving various aspects of social functioning in those in iduals who express social anhedonia.
Publisher: Wiley
Date: 26-10-2013
DOI: 10.1111/BJOP.12002
Abstract: Researchers have suggested that the psychoticism (P) personality dimension of the Eysenck Personality Questionnaire may be largely redundant with the agreeableness (A) and conscientiousness (C) constructs of the five-factor model. Little research has examined the distinctiveness of these constructs. We utilized a multi-wave, multi-method design to examine the ability of C, A, and P to uniquely predict a number of important outcomes amongst high school students. A total of 778 students (391 males, 387 females mean age 15.41 years.) completed personality measures in Grade 10. Self-reported self-esteem, social support, health-related behaviours, religious values as well as teachers' assessments of students, were collected 1 and 2 years later. A, C, and P were distinctive in their ability to predict these outcomes, after controlling for gender and socio-economic status as well as Grade 10 extraversion, openness, and neuroticism. The in idual P items explained unique variance over and above that explained by A and C. It was concluded that P is not merely the opposite of A and C. Implications for interventions are raised.
Publisher: S. Karger AG
Date: 2008
DOI: 10.1159/000155215
Abstract: i Background: /i Cannabis use has been identified as a possible risk factor for developing schizophrenia. In a previous paper we reported preliminary evidence that cannabis use increases the likelihood of psychosis-like experiences in non-clinical respondents who scored highly on a measure of schizotypy. We now present findings from pooled data from 3 new follow-up studies comprising a s le of 477 respondents, of whom 332 reported using cannabis at least once. i S ling and Methods: /i As in our previous study, the psychological effects of cannabis were assessed with the Cannabis Experiences Questionnaire, from which 3 subscales can be derived encompassing pleasurable experiences, psychosis-like experiences and after-effects. The respondents also completed the brief Schizotypal Personality Questionnaire. i Results: /i Cannabis use was reported by 70% of the s le. Use per se was not significantly related to schizotypy. However, high scoring schizotypes were more likely to report both psychosis-like experiences and unpleasant after-effects associated with cannabis use. The pleasurable effects of cannabis use were not related to schizotypy. Exploratory factor analysis of the pooled data from this study and our previous report (providing a s le of cannabis users) suggested a 3-factor solution. These were characterised as a psychotic-dysphoric index (factor 1), an expansive index (factor 2) and an intoxicated index (factor 3). Schizotypy was highly correlated with factors 1 and 3, though not with factor 2. i Conclusion: /i High scoring schizotypes who use cannabis are more likely to experience psychotic-dysphoric phenomena and intoxicating effects during and after use. Our results confirm and expand the findings reported in our previous study. They are consistent with the hypothesis that cannabis use may be a risk factor for full psychosis in this group.
Publisher: JMIR Publications Inc.
Date: 05-04-2013
DOI: 10.2196/JMIR.2328
Publisher: UCL Press
Date: 2022
DOI: 10.14324/111.444/UCLOE.100002
Abstract: The article provides commentary on Wong et al.’s investigation of the relationship between schizotypal traits, social mistrust and aggression, mental and physical health outcomes across three waves of data collection commencing in April 2020. The researchers aimed to consider the nature of the relationship between these variables and the stability of these relationships as coronavirus (Covid-19) restrictions fluctuated over time. Their results suggested that loneliness reflects a hub which links the trait variables of schizotypal and social mistrust to aggression and mental and physical health symptoms. Their network did not vary by demographic factors nor wave of data collection, suggesting that stable in idual differences were driving results. Their results propose that interventions which increase social connection could provide positive health benefits as well as decreasing aggression (via reductions in social mistrust). Their data contributes to understanding about how schizotypal traits link to outcomes under conditions of social stress.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 02-2010
Publisher: Informa UK Limited
Date: 07-2013
DOI: 10.1080/13811118.2013.805647
Abstract: It has been proposed that affective instability may be associated with thoughts about self-injury. The aim of this study was to test the hypotheses that instability in feelings of depression, but not anxiety, guilt, or hostility, would predict greater concurrent and subsequent thoughts about self-injury. Thirty-six in iduals with psychosis completed questions on touch-screen mobile phones at semi-random times each day for one week. The instability of depression predicted greater concurrent and subsequent levels of thoughts about self-injury, even when controlling for depression level. Conversely, self-injurious thoughts predicted more stable depression. The instability of guilt, anxiety, and hostility did not significantly predict levels of thoughts about self-injury. Results indicate that a variable depressive state may trigger the onset of thoughts about self-injury, which increases the risk of its subsequent recurrence. The onset of self-injurious thoughts may, however, have a stabilizing effect on subsequent depression.
Publisher: International Society for Neurofeedback Research (ISNR)
Date: 07-2012
Publisher: BMJ
Date: 04-2016
Publisher: Royal College of Psychiatrists
Date: 12-2007
Abstract: The nosological status of auditory hallucinations in non-clinical s les is unclear To investigate the functional neural basis of non-clinical hallucinations After selection from 1206 people, 68 participants of high, medium and low hallucination proneness completed a task designed to elicit verbal hallucinatory phenomena under conditions of stimulus degradation. Eight subjects who reported hearing a voice when none was present repeated the task during functional imaging During the signal detection task, the high hallucination-prone participants reported a voice to be present when it was not (false alarms) significantly more often than the average or low participants ( P .03, d.f. =2). On functional magnetic resonance imaging, patterns of activation during these false alarms showed activation in the superior and middle temporal cortex ( P .001) Auditory hallucinatory experiences reported in non-clinical s les appear to be mediated by similar patterns of cerebral activation as found during hallucinations in schizophrenia
Publisher: Cambridge University Press (CUP)
Date: 06-09-2011
DOI: 10.1017/S0033291711001826
Abstract: It has been proposed that the relationship between childhood trauma and hallucinations can be explained by dissociative processes. The present study examined whether the effect of childhood trauma on hallucination-proneness is mediated by dissociative tendencies. In addition, the influence of dissociative symptoms on a cognitive process believed to underlie hallucinatory experiences (i.e. reality discrimination the capacity to discriminate between internal and external cognitive events) was also investigated. Patients with schizophrenia spectrum disorders ( n =45) and healthy controls (with no history of hallucinations n =20) completed questionnaire measures of hallucination-proneness, dissociative tendencies and childhood trauma, as well as performing an auditory signal detection task. Compared to both healthy and non-hallucinating clinical controls, hallucinating patients reported both significantly higher dissociative tendencies and childhood sexual abuse. Dissociation positively mediated the effect of childhood trauma on hallucination-proneness. This mediational role was particularly robust for sexual abuse over other types of trauma. Signal detection abnormalities were evident in hallucinating patients and patients with a history of hallucinations, but were not associated with pathological dissociative symptoms. These results are consistent with dissociative accounts of the trauma-hallucinations link. Dissociation, however, does not affect reality discrimination. Future research should examine whether other cognitive processes associated with both dissociative states and hallucinations (e.g. deficits in cognitive inhibition) may explain the relationship between dissociation and hallucinatory experiences.
Publisher: Oxford University Press (OUP)
Date: 23-03-2012
Publisher: Informa UK Limited
Date: 03-11-2023
Publisher: Elsevier BV
Date: 06-2015
DOI: 10.1016/J.NEUROSCIENCE.2015.03.047
Abstract: Standards-referenced educational reform has increased the prevalence of standardized testing however, whether these tests accurately measure students' competencies has been questioned. This may be due to domain-specific assessments placing a differing domain-general cognitive load on test-takers. To investigate this possibility, functional magnetic resonance imaging (fMRI) was used to identify and quantify the neural correlates of performance on current, international standardized methods of spelling assessment. Out-of-scanner testing was used to further examine differences in assessment results. Results provide converging evidence that: (a) the spelling assessments differed in the cognitive load placed on test-takers (b) performance decreased with increasing cognitive load of the assessment and (c) brain regions associated with working memory were more highly activated during performance of assessments that were higher in cognitive load. These findings suggest that assessment design should optimize the cognitive load placed on test-takers, to ensure students' results are an accurate reflection of their true levels of competency.
Publisher: SAGE Publications
Date: 17-09-2010
Abstract: Intravenous (IV) Δ9-tetrahydrocannabinol (THC) induces transient psychotic symptoms in healthy subjects and in schizophrenic patients, but the psychotomimetic mechanism is unknown. One possibility is that THC stimulates dopamine (DA) release in the striatum. In this study we tested whether IV THC led to an increase in striatal DA release compared to placebo. We also investigated whether DA release and positive psychotic symptoms were related. Eleven healthy male volunteers completed two 123I-iodobenzamide ([123I]IBZM) single photon emission tomography (SPET) sessions and received IV THC (2.5 mg) or placebo in a randomized counterbalanced order, under double-blind conditions. Analysable data were obtained from nine participants. The Positive and Negative Syndrome Scale (PANSS) was used to rate psychotomimetic effects. Striatal binding index values were calculated using the occipital cortex as a reference region. Both the PANSS positive and general symptoms increased significantly at 30 min following IV THC. There were no significant differences in binding index in the caudate or putamen under THC compared to placebo conditions. Positive psychotic symptoms and DA release were unrelated. THC did not lead to a significant increase in DA release even though the dose was sufficient for participants to have psychotic symptoms. These findings do not support a central role for striatal DA in THC-elicited psychosis.
Publisher: Informa UK Limited
Date: 05-2011
DOI: 10.1080/13546805.2010.495244
Abstract: Recent studies have linked hallucination-proneness to dysfunctional metacognitive beliefs, dissociation, and disrupted capacity to discriminate between internal and external cognitive events (reality discrimination). This study addressed a number of methodological limitations of previous research by investigating the relationship between hallucination-proneness and the aforementioned variables while controlling for comorbid symptoms. A large s le of nonclinical participants was screened on measures of hallucination-proneness, cognitive intrusions, paranoid ideation, metacognitive beliefs, and dispositional mindfulness (including measures of dissociation-like experiences). In addition, a signal detection task was used to investigate reality discrimination in four subgroups of participants selected on the basis of their scores on hallucination-proneness and intrusions. Regression analyses for the self-report data were conducted to investigate the predictors of hallucination-proneness and paranoia when controlling for comorbid symptoms. Also, between-group differences on the behavioural data were tested to determine whether perturbed reality discrimination is specifically associated with hallucination-proneness rather than cognitive intrusions. Results revealed that metacognitive beliefs are more strongly associated with intrusions and paranoia than hallucination-proneness, whereas hallucination-proneness is related to perturbed reality discrimination and dissociation. These results clarify previous research on metacognitive dysfunction in hallucination-proneness, and highlight the importance of controlling for the covariation among symptoms when investigating the cognitive processes underlying psychotic experiences.
Publisher: Informa UK Limited
Date: 07-2011
DOI: 10.1080/13546805.2010.530472
Abstract: Auditory hallucinations exist in psychotic disorders as well as the general population. Proneness to hallucinations, as measured by positive schizotypy, predicts false perceptions during an auditory signal detection task (Barkus, Stirling, Hopkins, McKie, & Lewis, 2007). Our aim was to replicate this result and extend it by examining effects of age and sex, both important demographic predictors of psychosis. A s le of 76 healthy volunteers split into 15-17 years (n=46) and 19 years plus (n=30) underwent a signal detection task designed to detect propensity towards false perceptions under ambiguous auditory conditions. Scores on the Unusual Experiences subscale (UE) of the O-LIFE schizotypy scale, IQ, and a measure of working memory were also assessed. We replicated our initial finding (Barkus et al., 2007): High scores on positive schizotypy were associated with false perceptions. Younger participants who scored highly on positive schizotypy reported significantly more false perceptions compared to other groups (p=.04). Older participants who had had an imaginary friend reported more false perceptions during the signal detection task (p<.01). Younger participants seem most vulnerable to the effects of positive schizotypal traits in terms of a signal detection deficit that underlies auditory hallucinations. Schizotypy may have greatest impact closer to the risk period for development of psychotic disorders.
Publisher: Oxford University Press (OUP)
Date: 31-07-2019
Abstract: The COMT Val158Met polymorphism affects the availability of synaptic dopamine in the prefrontal cortex and has been widely studied as a genetic risk factor for psychosis. Schizotypy is associated with an increased risk of psychosis, with some studies implicating similar neurobiological mechanisms to schizophrenia. The present study sought to interrogate the link between the COMT Val158Met polymorphism and schizotypy using electroencephalogram (EEG) to identify neurophysiological mechanisms underpinning psychosis risk. Neurotypical (N = 91) adults were genotyped for the COMT Val158Met polymorphism, completed the Schizotypal Personality Questionnaire (SPQ), and had eyes open resting-state EEG recorded for 4 min. SPQ suspiciousness subscale scores were higher for in iduals homozygous for Val/Val and Met/Met versus Val/Met genotypes. Delta, theta, alpha-2, beta-1, and beta-2 litudes were lower for Val/Val than Met/Met in iduals. Lower theta litudes were correlated with higher total SPQ scores (P = 0.050), and multiple regression revealed that higher delta, and lower theta and beta-2 litudes (but not COMT genotype) best predicted total SPQ scores (P = 0.014). This study demonstrates the importance of COMT genotype in determining trait suspiciousness and EEG oscillatory activity. It also highlights relationships between dopaminergic alterations, EEG and schizotypy that are dissimilar to those observed in schizophrenia.
Publisher: Wiley
Date: 16-08-2011
DOI: 10.1111/J.1600-0447.2010.01596.X
Abstract: The experience s ling method (ESM) represents a valuable way of assessing clinical phenomena in real world settings and across time. Despite its theoretical advantages, using this methodology in psychiatric populations is challenging. This paper acts as a guide to researchers wishing to employ this approach when investigating mental illness. The contents represent the opinions of researchers around the United Kingdom and the Netherlands who are experienced at using the ESM. In ESM studies, participants are required to fill in questions about their current thoughts, feelings and experiences when prompted by an electronic device (e.g. a wristwatch, PDA). Entries are typically made at fixed or random intervals over 6 days. This article outlines how to design and validate an ESM diary. We then discuss which s ling procedure to use and how to increase compliance through effective briefing and telephone sessions. Debriefing, data management and analytical issues are considered, before suggestions for future clinical uses of the ESM are made. The last decade has seen an increase in the number of studies employing the ESM in clinical research. Further research is needed to examine the optimal equipment and procedure for different clinical groups.
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Emma Barkus.