ORCID Profile
0000-0002-8680-4346
Current Organisations
Neuroscience Research Australia
,
The University of Auckland
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Publisher: Elsevier BV
Date: 04-2012
DOI: 10.1016/J.NEUROPSYCHOLOGIA.2012.01.005
Abstract: Approximately half the world's population can now speak more than one language. Understanding the neural basis of language organisation in bilinguals, and whether the cortical networks involved during language processing differ from that of monolinguals, is therefore an important area of research. A main issue concerns whether L2 (second language) is processed using the same neural mechanisms that mediate L1 (first language) processing. Moderating factors include the age of L2 acquisition and the level of proficiency. Here we used a lexical decision task with five conditions during functional magnetic resonance imaging (fMRI) to investigate language processing in eight late proficient bilinguals when using Macedonian (L1) and English (L2). Bilinguals had greater bilateral activation during both L1 and L2 processing, and therefore weaker language lateralisation, compared to matched control English monolinguals. A greater amount of overall activation was also seen in bilinguals, especially during L2 conditions. Late proficient bilinguals living in their L2 environment employ a more extensive neural network than monolinguals when processing their second language.
Publisher: Elsevier BV
Date: 2022
DOI: 10.1016/J.JPSYCHIRES.2021.11.038
Abstract: Whilst alterations in emotional face processing, as indicated by event-related potentials (ERPs), are associated with depression and anxiety symptoms in clinical and non-clinical s les, it has remained unclear whether they are related to mental wellbeing. The current study aimed to address this question in a non-clinical s le. The analysis included 402 adult twins from the TWIN-E study. The COMPAS-W and the Depression Anxiety Stress Scale (DASS-42) were used to measure mental wellbeing and depression/anxiety symptoms, respectively. Participants viewed facial expressions under Unmasked (conscious) and Masked (subliminal) conditions while ERPs were recorded. The associations of emotion processing with mental wellbeing and depression/anxiety symptoms were assessed using multivariate linear mixed models. There was a strong association between depression/anxiety symptoms and the N170 litude difference for the Fear - Happy contrast in the Masked condition after controlling for wellbeing scores (B = 0.34, p < .001). Specifically, higher depression/anxiety symptoms were associated with a lack of differentiation between fearful and happy faces. No associations were found between emotional face processing and mental wellbeing scores. These results indicate that even within a non-clinical s le, alterations in emotional ERPs, namely the N170, reflect differences in depression/anxiety symptoms rather than differences in wellbeing. Furthermore, this effect was limited to automatic processing, rather than conscious processing of emotional stimuli, suggesting the observed differences apply only to the subconscious pathway.
Publisher: Elsevier BV
Date: 2019
DOI: 10.1016/J.NEUROPSYCHOLOGIA.2018.11.018
Abstract: It is well-known that both emotional and motivational events greatly impact our behaviour. Based on previous work on the interplay between these two constructs, the present study aimed to test whether and how concurrent emotion and reward signals interact in terms of their basic valence, when both are equally relevant to the task. To this end, we employed a novel fMRI paradigm in which reward availability was explicitly signalled by positive, neutral, or negative facial expressions (using block-wise instructions). Hence, in contrast to previous studies combining reward cues with irrelevant emotional stimuli, the present paradigm required participants to process the emotional information in order to respond and receive the reward. Compared to no-reward trials, we found performance benefits in trials in which reward was signalled by positive emotion, and performance detriments in trials in which reward was signalled by negative emotion - even though the reward value of the positive and negative emotion trials was identical. Neurally, reward trials signalled by negative emotion were associated with increased activity in frontal cognitive control regions, indicative of an induced conflict arising from a mismatch in absolute valence between reward and emotion. In contrast, reward trials signalled by positive emotion did not differentially increase activity anywhere in the brain (despite being associated with behavioural facilitation), which seems to support the notion of an inherent, and hence effortless, mapping between positive/rewarding stimuli and approach behaviour. Together, we interpret these patterns in terms of overlapping and non-overlapping valence signals (and associated response tendencies), which can induce benefits and costs, respectively.
Publisher: Elsevier BV
Date: 08-2021
Publisher: Springer Science and Business Media LLC
Date: 26-02-2022
DOI: 10.1038/S41398-022-01849-6
Abstract: Resilience is a process of adaptive recovery crucial in maintaining mental wellbeing after stress exposure. A psychological factor known to buffer stress and promote positive wellbeing outcomes is the ability to regulate emotions. However, the neural networks underlying resilience, and the possible mediating role of emotion regulation, remain largely unknown. Here, we examined the association between resilience and grey matter covariation (GMC) in healthy adults with and without early life stress (ELS) exposure, and whether emotion regulation mediated this brain-resilience association. Source-based morphometry was used to identify spatial patterns of common GMC in 242 healthy participants. Wellbeing was measured using the COMPAS-W Wellbeing Scale. Linear mixed models were run to establish associations between GMC and wellbeing scores. Moderated mediation models were used to examine a conditional mediating effect of emotion regulation on the brain-wellbeing relationship, moderated by ELS exposure. Distinct ELS-related morphometric patterns were found in association with resilience. In participants without ELS exposure, decreased GMC in the temporo-parietal regions was associated with wellbeing. In participants with ELS exposure, we observed increased patterns of covariation in regions related to the salience and executive control networks, and decreased GMC in temporo-parietal areas, which were associated with resilience. Cognitive reappraisal mediated the brain-wellbeing relationship in ELS-exposed participants only. Patterns of stronger GMC in regions associated with emotional and cognitive functioning in ELS-exposed participants with high levels of wellbeing may indicate possible neural signatures of resilience. This may be further heightened by utilising an adaptive form of emotion regulation.
Publisher: Elsevier BV
Date: 08-2015
Publisher: Wiley
Date: 09-09-2020
DOI: 10.1111/GBB.12694
Publisher: Elsevier BV
Date: 07-2015
DOI: 10.1016/J.NEUROPSYCHOLOGIA.2015.05.007
Abstract: Empirical studies indicate a link between creativity and schizotypal personality traits, where in iduals who score highly on schizotypy measures also display greater levels of creative behaviour. However, the exact nature of this relationship is not yet clear, with only a few studies examining this association using neuroimaging methods. In the present study, the neural substrates of creative thinking were assessed with a drawing task paradigm in healthy in iduals using fMRI. These regions were then statistically correlated with the participants' level of schizotypy as measured by the Oxford-Liverpool Inventory of Feelings and Experiences (O-LIFE), which is a questionnaire consisting of four dimensions. Neural activations associated with the creativity task were observed in bilateral inferior temporal gyri, left insula, left parietal lobule, right angular gyrus, as well as regions in the prefrontal cortex. This widespread pattern of activation suggests that creative thinking utilises multiple neurocognitive networks, with creative production being the result of collaboration between these regions. Furthermore, the correlational analyses found the Unusual Experiences factor of the O-LIFE to be the most common dimension associated with these areas, followed by the Impulsive Nonconformity dimension. These correlations were negative, indicating that in iduals who scored the highest in these factors displayed the least amount of activation when performing the creative task. This is in line with the idea that 'less is more' for creativity, where the deactivation of specific cortical areas may facilitate creativity. Thus, these findings contribute to the evidence of a common neural basis between creativity and schizotypy.
Publisher: Springer Science and Business Media LLC
Date: 11-04-2018
DOI: 10.3758/S13415-018-0587-3
Abstract: Although it is clear that emotional and motivational manipulations yield a strong influence on cognition and behaviour, these domains have mostly been investigated in independent research lines. Therefore, it remains poorly understood how far these affective manipulations overlap in terms of their underlying neural activations, especially in light of previous findings that suggest a shared valence mechanism across multiple affective processing domains (e.g., monetary incentives, primary rewards, emotional events). This is particularly interesting considering the commonality between emotional and motivational constructs in terms of their basic affective nature (positive vs. negative), but dissociations in terms of instrumentality, in that only reward-related stimuli are typically associated with performance-contingent outcomes. Here, we aimed to examine potential common neural processes triggered by emotional and motivational stimuli in matched tasks within participants using functional magnetic resonance imaging (fMRI). Across tasks, we found shared valence effects in the ventromedial prefrontal cortex and left inferior frontal gyrus (part of dorsolateral prefrontal cortex), with increased activity for positive and negative stimuli, respectively. Despite this commonality, emotion and reward tasks featured differential behavioural patterns in that negative valence effects (performance costs) were exclusive to emotional stimuli, while positive valence effects (performance benefits) were only observed for reward-related stimuli. Overall, our data suggest a common affective coding mechanism across different task domains and support the idea that monetary incentives entail signed basic valence signals, above and beyond the instruction to perform both gain and loss trials as accurately as possible to maximise the outcome.
Publisher: Elsevier BV
Date: 08-2016
DOI: 10.1016/J.CORTEX.2016.04.011
Abstract: Neuroimaging research into the brain structure of schizophrenia patients has shown consistent reductions in grey matter volume relative to healthy controls. Examining structural differences in in iduals with high levels of schizotypy may help elucidate the course of disorder progression, and provide further support for the schizotypy-schizophrenia continuum. Thus far, the few studies investigating grey matter differences in schizotypy have produced inconsistent results. In the current study, we used a multivariate partial least squares (PLS) approach to clarify the relationship between psychometric schizotypy (measured by the Oxford-Liverpool Inventory of Feelings and Experiences) and grey matter volume in 49 healthy adults. We found a negative association between all schizotypy dimensions and grey matter volume in the frontal and temporal lobes, as well as the insula. We also found a positive association between all schizotypy dimensions and grey matter volume in the parietal and temporal lobes, and in subcortical regions. Further correlational analyses revealed that positive and disorganised schizotypy were strongly associated with key regions (left superior temporal gyrus and insula) most consistently reported to be affected in schizophrenia and schizotypy. We also compared PLS with the typically used General Linear Model (GLM) and demonstrate that PLS can be reliably used as an extension to voxel-based morphometry (VBM) data. This may be particularly valuable for schizotypy research due to PLS' ability to detect small, but reliable effects. Together, the findings indicate that healthy schizotypal in iduals exhibit structural changes in regions associated with schizophrenia. This adds to the evidence of an overlap of phenotypic expression between schizotypy and schizophrenia, and may help establish biological endophenotypes for the disorder.
Publisher: Springer Science and Business Media LLC
Date: 27-10-2021
DOI: 10.1038/S41380-021-01359-9
Abstract: Neuroanatomical abnormalities have been reported along a continuum from at-risk stages, including high schizotypy, to early and chronic psychosis. However, a comprehensive neuroanatomical mapping of schizotypy remains to be established. The authors conducted the first large-scale meta-analyses of cortical and subcortical morphometric patterns of schizotypy in healthy in iduals, and compared these patterns with neuroanatomical abnormalities observed in major psychiatric disorders. The s le comprised 3004 unmedicated healthy in iduals (12–68 years, 46.5% male) from 29 cohorts of the worldwide ENIGMA Schizotypy working group. Cortical and subcortical effect size maps with schizotypy scores were generated using standardized methods. Pattern similarities were assessed between the schizotypy-related cortical and subcortical maps and effect size maps from comparisons of schizophrenia (SZ), bipolar disorder (BD) and major depression (MDD) patients with controls. Thicker right medial orbitofrontal/ventromedial prefrontal cortex (mOFC/vmPFC) was associated with higher schizotypy scores ( r = 0.067, p FDR = 0.02). The cortical thickness profile in schizotypy was positively correlated with cortical abnormalities in SZ ( r = 0.285, p spin = 0.024), but not BD ( r = 0.166, p spin = 0.205) or MDD ( r = −0.274, p spin = 0.073). The schizotypy-related subcortical volume pattern was negatively correlated with subcortical abnormalities in SZ (rho = −0.690, p spin = 0.006), BD (rho = −0.672, p spin = 0.009), and MDD (rho = −0.692, p spin = 0.004). Comprehensive mapping of schizotypy-related brain morphometry in the general population revealed a significant relationship between higher schizotypy and thicker mOFC/vmPFC, in the absence of confounding effects due to antipsychotic medication or disease chronicity. The cortical pattern similarity between schizotypy and schizophrenia yields new insights into a dimensional neurobiological continuity across the extended psychosis phenotype.
Publisher: Elsevier BV
Date: 07-2020
Publisher: Springer Science and Business Media LLC
Date: 04-02-2021
Publisher: Informa UK Limited
Date: 09-03-2016
Publisher: Cambridge University Press (CUP)
Date: 11-01-2023
DOI: 10.1017/S0033291721005262
Abstract: While previous studies have suggested that higher levels of cognitive performance may be related to greater wellbeing and resilience, little is known about the associations between neural circuits engaged by cognitive tasks and wellbeing and resilience, and whether genetics or environment contribute to these associations. The current study consisted of 253 monozygotic and dizygotic adult twins, including a subs le of 187 early-life trauma-exposed twins, with functional Magnetic Resonance Imaging data from the TWIN-E study. Wellbeing was measured using the COMPAS-W Wellbeing Scale while resilience was defined as a higher level of positive adaptation (higher levels of wellbeing) in the presence of trauma exposure. We probed both sustained attention and working memory processes using a Continuous Performance Task in the scanner. We found significant negative associations between resilience and activation in the bilateral anterior insula engaged during sustained attention. Multivariate twin modelling showed that the association between resilience and the left and right insula activation was mostly driven by common genetic factors, accounting for 71% and 87% of the total phenotypic correlation between these variables, respectively. There were no significant associations between wellbeing/resilience and neural activity engaged during working memory updating. The findings suggest that greater resilience to trauma is associated with less activation of the anterior insula during a condition requiring sustained attention but not working memory updating. This possibly suggests a pattern of ‘neural efficiency’ (i.e. more efficient and/or attenuated activity) in people who may be more resilient to trauma.
Publisher: Cambridge University Press (CUP)
Date: 02-08-2021
DOI: 10.1017/S0033291721002695
Abstract: Although mental wellbeing has been linked with positive health outcomes, including longevity and improved emotional and cognitive functioning, studies examining the underlying neural mechanisms of both subjective and psychological wellbeing have been sparse. We assessed whether both forms of wellbeing are associated with neural activity engaged during positive and negative emotion processing and the extent to which this association is driven by genetics or environment. We assessed mental wellbeing in 230 healthy adult monozygotic and dizygotic twins using a previously validated questionnaire (COMPAS-W) and undertook functional magnetic resonance imaging during a facial emotion viewing task. We used linear mixed models to analyse the association between COMPAS-W scores and emotion-elicited neural activation. Univariate twin modelling was used to evaluate heritability of each brain region. Multivariate twin modelling was used to compare twin pairs to assess the contributions of genetic and environmental factors to this association. Higher levels of wellbeing were associated with greater neural activity in the dorsolateral prefrontal cortex, localised in the right inferior frontal gyrus (IFG), in response to positive emotional expressions of happiness. Univariate twin modelling showed activity in the IFG to have 20% heritability. Multivariate twin modelling suggested that the association between wellbeing and positive emotion-elicited neural activity was driven by common variance from unique environment ( r = 0.208) rather than shared genetics. Higher mental wellbeing may have a basis in greater engagement of prefrontal neural regions in response to positive emotion, and this association may be modifiable by unique life experiences.
Publisher: Informa UK Limited
Date: 08-2012
DOI: 10.1080/13554794.2011.588182
Abstract: The aim of this study was to identify the neural substrates of an adult English-German bilingual with dyslexia (in both languages) during lexical decision-making using functional magnetic resonance imaging (fMRI). A lexical decision task with five conditions in a block design was employed (nonverbal shape judgment, lettercase judgment, regular word judgment, irregular word judgment, and nonword judgment), and the activation was compared to a non-dyslexic control bilingual and a control monolingual participant. Both of the control participants matched the dyslexic bilingual BK on age, sex, IQ, handedness, and education level. Results indicated that the bilingual adult with dyslexia was strongly right lateralized for stimuli that required phonological processing, a profile that differed particularly from the activation observed from the monolingual participant. These results are consistent with the idea of increased activation (mostly in the right hemisphere) during linguistic tasks in adults with dyslexia and in late proficient bilinguals relative to monolinguals. Findings also suggest that the additional activation observed in both of the bilinguals are similar, suggesting that these effects are not additive in the dyslexic bilingual.
Publisher: BMJ
Date: 07-2022
DOI: 10.1136/BMJOPEN-2021-058918
Abstract: Mental well-being is a core component of mental health, and resilience is a key process of positive adaptive recovery following adversity. However, we lack an understanding of the neural mechanisms that contribute to in idual variation in the trajectories of well-being and resilience relative to risk. Genetic and/or environmental factors may also modulate these mechanisms. The aim of the TWIN-10 Study is to characterise the trajectories of well-being and resilience over 12 years across four timepoints (baseline, 1 year, 10 years, 12 years) in 1669 Australian adult twins of European ancestry (to account for genetic stratification effects). To this end, we integrate data across genetics, environment, psychological self-report, neurocognitive performance and brain function measures of well-being and resilience. Twins who took part in the baseline TWIN-E Study will be invited back to participate in the TWIN-10 Study, at 10-year and 12-year follow-up timepoints. Participants will complete an online battery of psychological self-reports, computerised behavioural assessments of neurocognitive functions and MRI testing of the brain structure and function during resting and task-evoked scans. These measures will be used as predictors of the risk versus resilience trajectory groups defined by their changing levels of well-being and illness symptoms over time as a function of trauma exposure. Structural equation models will be used to examine the association between the predictors and trajectory groups of resilience and risk over time. Univariate and multivariate twin modelling will be used to determine heritability of the measures, as well as the shared versus unique genetic and environmental contributions. This study involves human participants. This study was approved by the University of New South Wales Human Research Ethics Committee (HC180403) and the Scientific Management Panel of Neuroscience Research Australia Imaging (CX2019-05). Results will be disseminated through publications and presentations to the public and the academic community. Participants gave informed consent to participate in the study before taking part.
Publisher: Informa UK Limited
Date: 21-06-2020
Publisher: Springer Science and Business Media LLC
Date: 07-03-2018
DOI: 10.1007/S11682-017-9700-4
Abstract: It has long been known from animal literature that the locus coeruleus (LC), the source region of noradrenergic neurons in the brain, is sensitive to unexpected, novel, and other salient events. In humans, however, direct assessment of LC activity has proven to be challenging due to its small size and difficult localization, which is why noradrenergic activity has often been assessed using more indirect measures such as electroencephalography (EEG) and pupil recordings. Here, we combined high-resolution functional magnetic resonance imaging (fMRI) with a special anatomical sequence to assess neural activity in the LC in response to different types of salient stimuli in an oddball paradigm (novel neutral oddballs, novel emotional oddballs, and familiar target oddballs). We found a significant linear increase of LC activity from standard trials, over familiar target oddballs, to novel neutral and novel emotional oddballs. Importantly, when breaking down this linear trend, only novel oddball stimuli led to robust activity increases as compared to standard trials, with no statistical difference between neutral and emotional ones. This pattern suggests that activity modulations in the LC in the present study were mainly driven by stimulus novelty, rather than by emotional saliency, task relevance, or contextual novelty alone. Moreover, the absence of significant activity modulations in response to target oddballs (which were reported in a recent study) suggests that the LC represents relative rather than absolute saliency of a stimulus in its respective context.
Publisher: Elsevier BV
Date: 07-2020
Publisher: Elsevier BV
Date: 02-2023
Publisher: Springer Science and Business Media LLC
Date: 20-02-2019
DOI: 10.3758/S13415-019-00692-5
Abstract: Previous research has shown that motivational signals bias action over inaction, which may be due to putative inherent valence-action mappings, similar to those observed in the emotional domain. In the present functional magnetic resonance imaging (fMRI) study we sought to investigate the neural underpinnings of such reward-related response tendencies, and in particular, how valence-action compatibility effects arising from predominant response tendencies are reflected at the neural level, and whether overlapping emotional valence lifies these effects. To this end, we employed an equiprobable (50:50) Go/NoGo task in which reward (reward/no-reward) and response mode (Go/NoGo) were signaled by orthogonal features of number targets that were overlaid on emotional images (positive, neutral, negative). Reward-related targets led to response facilitation (faster Go responses) and impairment in withholding responses (more NoGo commission errors), consistent with a reward-induced action bias. This pattern was paralleled by modulations in the left dorsolateral prefrontal cortex (dlPFC), with increased activity in no-reward as compared to reward-related Go trials, and the reversed pattern in NoGo trials. Albeit being processed in ventral visual areas, emotional background did not modulate performance in the present task, suggesting that irrelevant emotional information is globally outweighed by reward. In the current paradigm, which neither favors Go responses generally nor allows for differential preparation in Go versus NoGo trials, reward-related targets promote action over inaction. In turn, additional effort is needed to inhibit responses to these targets as well as to initiate responses to (less salient) no-reward targets, which may be considered as a downside of direct stimulus-reward associations.
Publisher: Frontiers Media SA
Date: 28-04-2021
DOI: 10.3389/FPSYT.2021.634925
Abstract: The unprecedented COVID-19 pandemic has led to lockdowns across the world with people being separated from their loved ones including partners, family, and friends. Here, using a large s le of 1,749 Australians and Americans, we investigated the impact of COVID-19 isolation on younger populations (13–25 years), and the influence of coping strategies and mental well-being on this impact. Overall, COVID-19 isolation had a more negative impact on adolescence (13–17 years) than young adulthood (18–25 years), but with no difference apparent between men and women, or between Australian and American residents. However, a deeper analysis revealed a gender-specific effect: the type of coping strategies differentially influenced the negative impact of COVID-19 isolation on men with various levels of well-being, an interaction effect not apparent in women. For men with lower levels of mental well-being, COVID-19 isolation appeared to have a less negative impact on them if they used more approach-oriented coping strategies (e.g., actively focusing on the problem). Our results provide cross-sectional evidence for a differential impact on young men at low levels of wellbeing by pandemic isolation. In sum, young men and adolescent boys with lower well-being coped better with COVID-19 isolation when they used more approach coping strategies.
Publisher: Wiley
Date: 29-06-2022
DOI: 10.1002/HBM.25993
Abstract: Wellbeing, an important component of mental health, is influenced by genetic and environmental factors. Previous association studies between brain structure and wellbeing have typically focused on volumetric measures and employed small cohorts. Using the UK Biobank Resource, we explored the relationships between wellbeing and brain morphometrics (volume, thickness and surface area) at both phenotypic and genetic levels. The s le comprised 38,982 participants with neuroimaging and wellbeing phenotype data, of which 19,234 had genotypes from which wellbeing polygenic scores (PGS) were calculated. We examined the association of wellbeing phenotype and PGS with all brain regions (including cortical, subcortical, brainstem and cerebellar regions) using multiple linear models, including (1) basic neuroimaging covariates and (2) additional demographic factors that may synergistically impact wellbeing and its neural correlates. Genetic correlations between genomic variants influencing wellbeing and brain structure were also investigated. Small but significant associations between wellbeing and volumes of several cerebellar structures ( β = 0.015–0.029, P FDR = 0.007–3.8 × 10 −9 ), brainstem, nucleus accumbens and caudate were found. Cortical associations with wellbeing included volume of right lateral occipital, thickness of bilateral lateral occipital and cuneus, and surface area of left superior parietal, supramarginal and pre‐ ost‐central regions. Wellbeing‐PGS was associated with cerebellar volumes and supramarginal surface area. Small mediation effects of wellbeing phenotype and PGS on right VIIIb cerebellum were evident. No genetic correlation was found between wellbeing and brain morphometric measures. We provide a comprehensive overview of wellbeing‐related brain morphometric variation. Notably, small effect sizes reflect the multifaceted nature of this concept.
No related grants have been discovered for Haeme Park.