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Fernandez VG, Asarnow R, Hodges M, Nuechterlein KH. Linguistic and neurocognitive correlates of probabilistic classification learning in schizophrenia. SCHIZOPHRENIA RESEARCH-COGNITION 2021; 26:100209. [PMID: 34354933 PMCID: PMC8321954 DOI: 10.1016/j.scog.2021.100209] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 07/07/2021] [Accepted: 07/13/2021] [Indexed: 10/25/2022]
Abstract
Individuals with schizophrenia demonstrate impaired implicit learning on cognitively complex tasks and preserved implicit motor learning. However, little is known about how implicit learning may be related to other linguistic and cognitive variables, including development of complex language including comprehension and syntax. This study explored the relationship between probabilistic classification learning, a type of implicit learning style, and linguistic and cognitive skills in schizophrenia. This was done by examining how schizophrenia patients perform on the Weather Prediction Task (WPT) relative to controls, particularly during a dual-task interference condition that assesses task automaticity. Individuals with schizophrenia (N = 34) demonstrated depressed cognitive functioning relative to the controls (N = 18) across nearly all cognitive functions. On the Weather Prediction Task, the schizophrenia group performed less accurately than the control group in later blocks and had a relatively flat learning curve. A significant Group X Block effect when controlling for age and sex suggested differential learning throughout the task. A subgroup of patients did not develop automaticity during the repeated blocks of trials. For those patients who did not develop automaticity over the course of the WPT, linguistic and cognitive skills were strongly correlated with their Block 1 performance. For patients who developed automaticity, overall neurocognitive ability was correlated with their ultimate level of performance on the WPT but not with their Block 1 performance. That language was related to differential learning emphasizes the role of explicit, verbal processes on making initial rapid improvement on the WPT.
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Affiliation(s)
- Vindia G Fernandez
- Department of Psychiatry and Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior, Geffen School of Medicine at UCLA, Los Angeles, CA, United States of America
| | - Robert Asarnow
- Department of Psychiatry and Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior, Geffen School of Medicine at UCLA, Los Angeles, CA, United States of America.,Department of Psychology, UCLA, Los Angeles, CA, United States of America
| | - Megan Hodges
- Department of Psychology, UCLA, Los Angeles, CA, United States of America
| | - Keith H Nuechterlein
- Department of Psychiatry and Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior, Geffen School of Medicine at UCLA, Los Angeles, CA, United States of America.,Department of Psychology, UCLA, Los Angeles, CA, United States of America
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Karcher NR, Hua JPY, Kerns JG. Probabilistic Category Learning and Striatal Functional Activation in Psychosis Risk. Schizophr Bull 2019; 45:396-404. [PMID: 29590478 PMCID: PMC6403050 DOI: 10.1093/schbul/sby033] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
BACKGROUND Psychosis risk is associated with striatal dysfunction, including a previous behavioral study that found that psychosis risk is associated with impaired performance on a probabilistic category learning task (PCLT; ie, the Weather Prediction Task), a task strongly associated with striatal activation. The current study examined whether psychosis risk based on symptom levels was associated with both poor behavioral performance and task-related physiological dysfunction in specific regions of the striatum while performing the PCLT. METHODS There were 2 groups of participants: psychosis risk (n = 21) who had both (a) extreme levels of self-reported psychotic-like beliefs and experiences and (b) interview-rated current attenuated psychotic symptoms (APS); and a comparison group (n = 20) who had average levels of self-reported psychotic-like beliefs and experiences. Participants completed the PCLT during fMRI scanning. RESULTS The current research replicated previous work finding behavioral PCLT deficits at the end of the task in psychosis risk. Furthermore, as expected, the psychosis risk group exhibited decreased striatal activation on the task, especially in the associative striatum. The psychosis risk group also displayed decreased activation in a range of cortical regions connected to the associative striatum. In contrast, the psychosis risk group exhibited greater activation predominantly in cortical regions not connected to the associative striatum. CONCLUSIONS Psychosis risk was associated with both behavioral and striatal dysfunction during performance on the PCLT, suggesting that behavioral and imaging measures using this task could be a marker for psychosis risk.
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Affiliation(s)
- Nicole R Karcher
- Department of Psychological Sciences, University of Missouri, Columbia, MO,Department of Psychiatry, Washington University School of Medicine, St. Louis, MO,To whom correspondence should be addressed; Department of Psychological Sciences, University of Missouri, 214 McAlester Hall, Columbia, MO 65211; tel: 573-882-8846, fax: 573-882-7710, e-mail:
| | - Jessica P Y Hua
- Department of Psychological Sciences, University of Missouri, Columbia, MO
| | - John G Kerns
- Department of Psychological Sciences, University of Missouri, Columbia, MO
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Li M, Li Y, Sun J, Shao D, Yang Q, Cao F. Variability of ecological executive function in children and adolescents genetically at high risk for schizophrenia: a latent class analysis. Eur Child Adolesc Psychiatry 2019; 28:237-245. [PMID: 29802516 DOI: 10.1007/s00787-018-1168-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 05/15/2018] [Indexed: 11/26/2022]
Abstract
Executive impairments have been observed both in patients with schizophrenia and in their unaffected first-degree relatives. Very few studies have investigated neurocognitive subgroups in unaffected first-degree relatives and in healthy participants using data-driven methods. The study included a high-risk group consisting of 100 unaffected young offspring and siblings of patients with schizophrenia and 198 healthy controls, all aged between 9 and 23 years. Executive function, victimization, and emotional and behavioral problems of participants were assessed by a series of self-report scales. Neurocognitive subgroups were investigated using latent class analysis of executive function measures. Four neurocognitive clusters were identified: a good performance cluster, a good self-control cluster, a low self-control cluster, and a severe impairment cluster. Participants in severe impaired executive function cluster reported a significantly higher level of victimization and had more prominent emotional and behavioral problems than the good performance cluster. Neurocognitive differences between high-risk young people and healthy controls were driven by individuals who have severe and global, rather than selective, executive deficits. Our results may provide clues to an explanation of the mechanisms behind executive impairments in young individuals at genetic risk and help to identify new targets for early interventions.
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Affiliation(s)
- Meng Li
- School of Nursing, Shandong University, No. 44 Wenhua Xi Road, Jinan, 250012, Shandong, People's Republic of China
| | - Yang Li
- School of Nursing, University of Michigan, Ann Arbor, MI, USA
| | - Jiwei Sun
- School of Nursing, Shandong University, No. 44 Wenhua Xi Road, Jinan, 250012, Shandong, People's Republic of China
| | - Di Shao
- School of Nursing, Shandong University, No. 44 Wenhua Xi Road, Jinan, 250012, Shandong, People's Republic of China
| | - Qianqian Yang
- School of Nursing, Shandong University, No. 44 Wenhua Xi Road, Jinan, 250012, Shandong, People's Republic of China
| | - Fenglin Cao
- School of Nursing, Shandong University, No. 44 Wenhua Xi Road, Jinan, 250012, Shandong, People's Republic of China.
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Forsyth JK, Bachman P, Mathalon DH, Roach BJ, Ye E, Asarnow RF. Effects of Augmenting N-Methyl-D-Aspartate Receptor Signaling on Working Memory and Experience-Dependent Plasticity in Schizophrenia: An Exploratory Study Using Acute d-cycloserine. Schizophr Bull 2017; 43:1123-1133. [PMID: 28338977 PMCID: PMC5581900 DOI: 10.1093/schbul/sbw193] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Cognitive deficits in schizophrenia have been hypothesized to reflect N-methyl-D-aspartate receptor (NMDAR) dysfunction. However, the mechanisms through which the NMDAR contributes to individual cognitive functions differ. To explore how NMDAR signaling relates to specific cognitive deficits in schizophrenia, we tested the effects of enhancing NMDAR signaling on working memory and experience-dependent plasticity using d-cycloserine (DCS). Plasticity was assessed using an EEG paradigm that utilizes high-frequency visual stimulation (HFvS) to induce neural potentiation, and 2 learning tasks, the information integration (IIT) and weather prediction (WPT) tasks. Working memory was assessed using an N-back task. Forty-five schizophrenia patients were randomized to receive a single 100 mg DCS dose (SZ-DCS; n = 24) or placebo (SZ-PLC; n = 21) in a double-blind, between-groups design. Testing occurred on a single day after placebo or DCS administration; baseline values were not obtained. DCS did not affect plasticity, as indicated by similar neural potentiation, and similar IIT and WPT learning between groups. However, among patients who successfully engaged in the working memory task (ie, performed above chance), SZ-DCS (n = 17) showed superior 2-back performance compared to SZ-PLC (n = 16). Interestingly, SZ-DCS also showed larger pre-HFvS neural responses during the LTP task. Notably, this pattern of DCS effects is the opposite of those found in our prior study of healthy adults. Results are consistent with target engagement of the NMDAR by DCS, but suggest that NMDAR signaling was not translated into synaptic plasticity changes in schizophrenia. Results highlight the importance of considering how distinct NMDAR-associated processes contribute to individual cognitive deficits in schizophrenia.
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Affiliation(s)
- Jennifer K Forsyth
- Department of Psychology, University of California, Los Angeles, Los Angeles, CA
| | - Peter Bachman
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA
| | - Daniel H Mathalon
- Department of Psychiatry and Biomedical Sciences, University of California, San Francisco, San Francisco, CA;,San Francisco Veterans Affairs Medical Center, San Francisco, CA
| | - Brian J Roach
- San Francisco Veterans Affairs Medical Center, San Francisco, CA
| | - Elissa Ye
- Department of Psychology, University of California, Los Angeles, Los Angeles, CA
| | - Robert F Asarnow
- Department of Psychology, University of California, Los Angeles, Los Angeles, CA;,Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, Los Angeles, CA,To whom correspondence should be addressed; Department of Psychology, University of California, Los Angeles, 760 Westwood Plaza, Los Angeles, CA 90095; tel: (310) 825-0394, fax: (310) 206-4446, e-mail:
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Korostil M, Remington G, McIntosh AR. Practice and Learning: Spatiotemporal Differences in Thalamo-Cortical-Cerebellar Networks Engagement across Learning Phases in Schizophrenia. Front Psychiatry 2017; 7:212. [PMID: 28167919 PMCID: PMC5256117 DOI: 10.3389/fpsyt.2016.00212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 12/22/2016] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Understanding how practice mediates the transition of brain-behavior networks between early and later stages of learning is constrained by the common approach to analysis of fMRI data. Prior imaging studies have mostly relied on a single scan, and parametric, task-related analyses. Our experiment incorporates a multisession fMRI lexicon-learning experiment with multivariate, whole-brain analysis to further knowledge of the distributed networks supporting practice-related learning in schizophrenia (SZ). METHODS Participants with SZ were compared with healthy control (HC) participants as they learned a novel lexicon during two fMRI scans over a several day period. All participants were trained to equal task proficiency prior to scanning. Behavioral-Partial Least Squares, a multivariate analytic approach, was used to analyze the imaging data. Permutation testing was used to determine statistical significance and bootstrap resampling to determine the reliability of the findings. RESULTS With practice, HC participants transitioned to a brain-accuracy network incorporating dorsostriatal regions in late-learning stages. The SZ participants did not transition to this pattern despite comparable behavioral results. Instead, successful learners with SZ were differentiated primarily on the basis of greater engagement of perceptual and perceptual-integration brain regions. CONCLUSION There is a different spatiotemporal unfolding of brain-learning relationships in SZ. In SZ, given the same amount of practice, the movement from networks suggestive of effortful learning toward subcortically driven procedural one differs from HC participants. Learning performance in SZ is driven by varying levels of engagement in perceptual regions, which suggests perception itself is impaired and may impact downstream, "higher level" cognition.
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Affiliation(s)
- Michele Korostil
- Centre for Addiction and Mental Health, Toronto, ON, Canada
- Rotman Research Institute of Baycrest Health Sciences, Toronto, ON, Canada
- University of Toronto, Toronto, ON, Canada
| | - Gary Remington
- Centre for Addiction and Mental Health, Toronto, ON, Canada
- University of Toronto, Toronto, ON, Canada
| | - Anthony Randal McIntosh
- Rotman Research Institute of Baycrest Health Sciences, Toronto, ON, Canada
- University of Toronto, Toronto, ON, Canada
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Karcher NR, Martin EA, Kerns JG. Examining associations between psychosis risk, social anhedonia, and performance of striatum-related behavioral tasks. JOURNAL OF ABNORMAL PSYCHOLOGY 2016; 124:507-18. [PMID: 26075968 DOI: 10.1037/abn0000067] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Both psychosis and anhedonia have been associated to some extent with striatal functioning. The current study examined whether either psychosis risk or social anhedonia was associated with performance on 3 tasks related to striatal functioning. Psychosis risk participants had extremely elevated Perceptual Aberration/Magical Ideation (PerMag) scores (n = 69), with 43% of psychosis risk participants also having semistructured interview-assessed psychotic-like experiences which further heightens their risk of psychotic disorder (Chapman, Chapman, Kwapil, Eckblad, & Zinser, 1994). Compared with both extremely elevated social anhedonia (n = 60) and control (n = 68) groups, the PerMag group exhibited poorer performance on 2 of the striatum-related tasks, the Weather Prediction Task (WPT) and the Learned Irrelevance Paradigm, but not on Finger Tapping. In addition, PerMag participants with psychotic-like experiences were especially impaired on the WPT. Overall, this study arguably provides the first evidence that psychosis risk but not social anhedonia is associated with performance on the WPT, a task thought to be strongly associated with activation in the associative striatum, and also suggests that the WPT might be especially useful as a behavioral measure of psychosis risk.
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Skilleter AJ, Weickert CS, Vercammen A, Lenroot R, Weickert TW. Peripheral BDNF: a candidate biomarker of healthy neural activity during learning is disrupted in schizophrenia. Psychol Med 2015; 45:841-854. [PMID: 25162472 PMCID: PMC4413857 DOI: 10.1017/s0033291714001925] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2014] [Revised: 07/16/2014] [Accepted: 07/16/2014] [Indexed: 12/26/2022]
Abstract
BACKGROUND Brain-derived neurotrophic factor (BDNF) is an important regulator of synaptogenesis and synaptic plasticity underlying learning. However, a relationship between circulating BDNF levels and brain activity during learning has not been demonstrated in humans. Reduced brain BDNF levels are found in schizophrenia and functional neuroimaging studies of probabilistic association learning in schizophrenia have demonstrated reduced activity in a neural network that includes the prefrontal and parietal cortices and the caudate nucleus. We predicted that brain activity would correlate positively with peripheral BDNF levels during probabilistic association learning in healthy adults and that this relationship would be altered in schizophrenia. METHOD Twenty-five healthy adults and 17 people with schizophrenia or schizo-affective disorder performed a probabilistic association learning test during functional magnetic resonance imaging (fMRI). Plasma BDNF levels were measured by enzyme-linked immunosorbent assay (ELISA). RESULTS We found a positive correlation between circulating plasma BDNF levels and brain activity in the parietal cortex in healthy adults. There was no relationship between plasma BDNF levels and task-related activity in the prefrontal, parietal or caudate regions in schizophrenia. A direct comparison of these relationships between groups revealed a significant diagnostic difference. CONCLUSIONS This is the first study to show a relationship between peripheral BDNF levels and cortical activity during learning, suggesting that plasma BDNF levels may reflect learning-related brain activity in healthy humans. The lack of relationship between plasma BDNF and task-related brain activity in patients suggests that circulating blood BDNF may not be indicative of learning-dependent brain activity in schizophrenia.
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Affiliation(s)
- A. J. Skilleter
- School of Psychiatry,
University of New South Wales, Kensington,
NSW, Australia
- Neuroscience Research Australia,
Randwick, NSW, Australia
- Schizophrenia Research Institute,
Darlinghurst, NSW, Australia
| | - C. S. Weickert
- School of Psychiatry,
University of New South Wales, Kensington,
NSW, Australia
- Neuroscience Research Australia,
Randwick, NSW, Australia
- Schizophrenia Research Institute,
Darlinghurst, NSW, Australia
| | - A. Vercammen
- School of Psychiatry,
University of New South Wales, Kensington,
NSW, Australia
- Neuroscience Research Australia,
Randwick, NSW, Australia
- Schizophrenia Research Institute,
Darlinghurst, NSW, Australia
| | - R. Lenroot
- School of Psychiatry,
University of New South Wales, Kensington,
NSW, Australia
- Neuroscience Research Australia,
Randwick, NSW, Australia
- Schizophrenia Research Institute,
Darlinghurst, NSW, Australia
| | - T. W. Weickert
- School of Psychiatry,
University of New South Wales, Kensington,
NSW, Australia
- Neuroscience Research Australia,
Randwick, NSW, Australia
- Schizophrenia Research Institute,
Darlinghurst, NSW, Australia
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Wagshal D, Knowlton BJ, Cohen JR, Bookheimer SY, Bilder RM, Fernandez VG, Asarnow RF. Cognitive correlates of gray matter abnormalities in adolescent siblings of patients with childhood-onset schizophrenia. Schizophr Res 2015; 161:345-50. [PMID: 25541139 PMCID: PMC4405249 DOI: 10.1016/j.schres.2014.12.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Revised: 12/03/2014] [Accepted: 12/05/2014] [Indexed: 01/04/2023]
Abstract
Patients with childhood onset schizophrenia (COS) display widespread gray matter (GM) structural brain abnormalities. Healthy siblings of COS patients share some of these structural abnormalities, suggesting that GM abnormalities are endophenotypes for schizophrenia. Another possible endophenotype for schizophrenia that has been relatively unexplored is corticostriatal dysfunction. The corticostriatal system plays an important role in skill learning. Our previous studies have demonstrated corticostriatal dysfunction in COS siblings with a profound skill learning deficit and abnormal pattern of brain activation during skill learning. This study investigated whether structural abnormalities measured using volumetric brain morphometry (VBM) were present in siblings of COS patients and whether these were related to deficits in cognitive skill learning. Results revealed smaller GM volume in COS siblings relative to controls in a number of regions, including occipital, parietal, and subcortical regions including the striatum, and greater GM volume relative to controls in several subcortical regions. Volume in the right superior frontal gyrus and cerebellum were related to performance differences between groups on the weather prediction task, a measure of cognitive skill learning. Our results support the idea that corticostriatal and cerebellar impairment in unaffected siblings of COS patients are behaviorally relevant and may reflect genetic risk for schizophrenia.
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Affiliation(s)
- Dana Wagshal
- University of California San Francisco, United States.
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Skilleter AJ, Weickert CS, Moustafa AA, Gendy R, Chan M, Arifin N, Mitchell PB, Weickert TW. BDNF val66met genotype and schizotypal personality traits interact to influence probabilistic association learning. Behav Brain Res 2014; 274:137-42. [PMID: 25125238 DOI: 10.1016/j.bbr.2014.07.041] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 07/24/2014] [Accepted: 07/27/2014] [Indexed: 02/04/2023]
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 individuals 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 samples 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.
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Affiliation(s)
- Ashley Jayne Skilleter
- School of Psychiatry, University of New South Wales, Randwick, NSW, Australia; Schizophrenia Research Institute, Darlinghurst, NSW, Australia; Neuroscience Research Australia, Randwick, NSW, Australia
| | - Cynthia Shannon Weickert
- School of Psychiatry, University of New South Wales, Randwick, NSW, Australia; Schizophrenia Research Institute, Darlinghurst, NSW, Australia; Neuroscience Research Australia, Randwick, NSW, Australia
| | - Ahmed Abdelhalim Moustafa
- School of Social Sciences and Psychology, Marcs Institute for Brain and Behaviour, University of Western Sydney, Penrith, NSW, Australia
| | - Rasha Gendy
- School of Medicine, University of New South Wales, Randwick, NSW, Australia
| | - Mico Chan
- School of Medicine, University of New South Wales, Randwick, NSW, Australia
| | - Nur Arifin
- School of Medicine, University of New South Wales, Randwick, NSW, Australia
| | - Philip Bowden Mitchell
- School of Psychiatry, University of New South Wales, Randwick, NSW, Australia; Black Dog Institute, Randwick, NSW, Australia
| | - Thomas Wesley Weickert
- School of Psychiatry, University of New South Wales, Randwick, NSW, Australia; Schizophrenia Research Institute, Darlinghurst, NSW, Australia; Neuroscience Research Australia, Randwick, NSW, Australia.
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