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Larsen KM, Madsen KS, Ver Loren van Themaat AH, Thorup AAE, Plessen KJ, Mors O, Nordentoft M, Siebner HR. Children at Familial High risk of Schizophrenia and Bipolar Disorder Exhibit Altered Connectivity Patterns During Pre-attentive Processing of an Auditory Prediction Error. Schizophr Bull 2024; 50:166-176. [PMID: 37379847 PMCID: PMC10754183 DOI: 10.1093/schbul/sbad092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 06/30/2023]
Abstract
BACKGROUND AND HYPOTHESIS Individuals with schizophrenia or bipolar disorder have attenuated auditory mismatch negativity (MMN) responses, indicating impaired sensory information processing. Computational models of effective connectivity between brain areas underlying MMN responses show reduced connectivity between fronto-temporal areas in individuals with schizophrenia. Here we ask whether children at familial high risk (FHR) of developing a serious mental disorder show similar alterations. STUDY DESIGN We recruited 67 children at FHR for schizophrenia, 47 children at FHR for bipolar disorder as well as 59 matched population-based controls from the Danish High Risk and Resilience study. The 11-12-year-old participants engaged in a classical auditory MMN paradigm with deviations in frequency, duration, or frequency and duration, while we recorded their EEG. We used dynamic causal modeling (DCM) to infer on the effective connectivity between brain areas underlying MMN. STUDY RESULTS DCM yielded strong evidence for differences in effective connectivity among groups in connections from right inferior frontal gyrus (IFG) to right superior temporal gyrus (STG), along with differences in intrinsic connectivity within primary auditory cortex (A1). Critically, the 2 high-risk groups differed in intrinsic connectivity in left STG and IFG as well as effective connectivity from right A1 to right STG. Results persisted even when controlling for past or present psychiatric diagnoses. CONCLUSIONS We provide novel evidence that connectivity underlying MMN responses in children at FHR for schizophrenia and bipolar disorder is altered at the age of 11-12, echoing findings that have been found in individuals with manifest schizophrenia.
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Affiliation(s)
- Kit Melissa Larsen
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital - Amager and Hvidovre, Copenhagen, Denmark
| | - Kathrine Skak Madsen
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital - Amager and Hvidovre, Copenhagen, Denmark
| | - Anna Hester Ver Loren van Themaat
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital - Amager and Hvidovre, Copenhagen, Denmark
| | - Anne Amalie Elgaard Thorup
- Child and Adolescent Mental Health Centre, Mental Health Services, Capital Region of Denmark, Hellerup, Denmark
- Copenhagen Research Centre for Mental Health - CORE, Mental Health Centre Copenhagen, Mental Health Services, Capital Region of Denmark, Copenhagen, Denmark
- The Lundbeck Foundation Initiative for Integrative Psychiatric Research (iPSYCH), Aarhus, Denmark
| | - Kerstin Jessica Plessen
- Child and Adolescent Mental Health Centre, Mental Health Services, Capital Region of Denmark, Hellerup, Denmark
- Department of Psychiatry, Service of Child and Adolescent Psychiatry, University Medical Center, University of Lausanne, Switzerland
| | - Ole Mors
- The Lundbeck Foundation Initiative for Integrative Psychiatric Research (iPSYCH), Aarhus, Denmark
- Psychosis Research Unit, Aarhus University Hospital Psychiatry, Aarhus, Denmark
| | - Merete Nordentoft
- Copenhagen Research Centre for Mental Health - CORE, Mental Health Centre Copenhagen, Mental Health Services, Capital Region of Denmark, Copenhagen, Denmark
- The Lundbeck Foundation Initiative for Integrative Psychiatric Research (iPSYCH), Aarhus, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Hartwig Roman Siebner
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital - Amager and Hvidovre, Copenhagen, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Neurology, Copenhagen University Hospital Bispebjerg, Copenhagen, Denmark
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Francisco AA, Foxe JJ, Molholm S. Event-related potential (ERP) markers of 22q11.2 deletion syndrome and associated psychosis. J Neurodev Disord 2023; 15:19. [PMID: 37328766 PMCID: PMC10273715 DOI: 10.1186/s11689-023-09487-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 06/07/2023] [Indexed: 06/18/2023] Open
Abstract
22q11.2 deletion syndrome (22q11.2DS) is a multisystemic disorder characterized by a wide range of clinical features, ranging from life-threatening to less severe conditions. One-third of individuals with the deletion live with mild to moderate intellectual disability; approximately 60% meet criteria for at least one psychiatric condition.22q11.2DS has become an important model for several medical, developmental, and psychiatric disorders. We have been particularly interested in understanding the risk for psychosis in this population: Approximately 30% of the individuals with the deletion go on to develop schizophrenia. The characterization of cognitive and neural differences between those individuals who develop schizophrenia and those who do not, despite being at genetic risk, holds important promise in what pertains to the clarification of paths to disease and to the development of tools for early identification and intervention.Here, we review our previous event-related potential (ERP) findings as potential markers for 22q11.2DS and the associated risk for psychosis, while discussing others' work. We focus on auditory processing (auditory-evoked potentials, auditory adaptation, and auditory sensory memory), visual processing (visual-evoked potentials and visual adaptation), and inhibition and error monitoring.The findings discussed suggest basic mechanistic and disease process effects on neural processing in 22q11.2DS that are present in both early sensory and later cognitive processing, with possible implications for phenotype. In early sensory processes, both during auditory and visual processing, two mechanisms that impact neural responses in opposite ways seem to coexist-one related to the deletion, which increases brain responses; another linked to psychosis, decreasing neural activity. Later, higher-order cognitive processes may be equally relevant as markers for psychosis. More specifically, we argue that components related to error monitoring may hold particular promise in the study of risk for schizophrenia in the general population.
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Affiliation(s)
- Ana A Francisco
- Department of Pediatrics, The Cognitive Neurophysiology Laboratory, Albert Einstein College of Medicine, Bronx, NY, USA.
| | - John J Foxe
- Department of Pediatrics, The Cognitive Neurophysiology Laboratory, Albert Einstein College of Medicine, Bronx, NY, USA
- Department of Neuroscience, Rose F. Kennedy Center, Albert Einstein College of Medicine, Bronx, NY, USA
- Department of Neuroscience, The Frederick J. and Marion A, Schindler Cognitive Neurophysiology Laboratory, The Ernest J. Del Monde Institute for Neuroscience, University of Rochester, School of Medicine and Dentistry, Rochester, NY, USA
| | - Sophie Molholm
- Department of Pediatrics, The Cognitive Neurophysiology Laboratory, Albert Einstein College of Medicine, Bronx, NY, USA.
- Department of Neuroscience, Rose F. Kennedy Center, Albert Einstein College of Medicine, Bronx, NY, USA.
- Department of Neuroscience, The Frederick J. and Marion A, Schindler Cognitive Neurophysiology Laboratory, The Ernest J. Del Monde Institute for Neuroscience, University of Rochester, School of Medicine and Dentistry, Rochester, NY, USA.
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Preterm neonates distinguish rhythm violation through a hierarchy of cortical processing. Dev Cogn Neurosci 2022; 58:101168. [PMID: 36335806 PMCID: PMC9638730 DOI: 10.1016/j.dcn.2022.101168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 09/29/2022] [Accepted: 10/27/2022] [Indexed: 01/13/2023] Open
Abstract
Rhythm is a fundamental component of the auditory world, present even during the prenatal life. While there is evidence that some auditory capacities are already present before birth, whether and how the premature neural networks process auditory rhythm is yet not known. We investigated the neural response of premature neonates at 30-34 weeks gestational age to violations from rhythmic regularities in an auditory sequence using high-resolution electroencephalography and event-related potentials. Unpredicted rhythm violations elicited a fronto-central mismatch response, indicating that the premature neonates detected the rhythmic regularities. Next, we examined the cortical effective connectivity underlying the elicited mismatch response using dynamic causal modeling. We examined the connectivity between cortical sources using a set of 16 generative models that embedded alternate hypotheses about the role of the frontal cortex as well as backward fronto-temporal connection. Our results demonstrated that the processing of rhythm violations was not limited to the primary auditory areas, and as in the case of adults, encompassed a hierarchy of temporo-frontal cortical structures. The result also emphasized the importance of top-down (backward) projections from the frontal cortex in explaining the mismatch response. Our findings demonstrate a sophisticated cortical structure underlying predictive rhythm processing at the onset of the thalamocortical and cortico-cortical circuits, two months before term.
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Gass N, Peterson Z, Reinwald J, Sartorius A, Weber-Fahr W, Sack M, Chen J, Cao H, Didriksen M, Stensbøl TB, Klemme G, Schwarz AJ, Schwarz E, Meyer-Lindenberg A, Nickl-Jockschat T. Differential resting-state patterns across networks are spatially associated with Comt and Trmt2a gene expression patterns in a mouse model of 22q11.2 deletion. Neuroimage 2021; 243:118520. [PMID: 34455061 DOI: 10.1016/j.neuroimage.2021.118520] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 07/14/2021] [Accepted: 08/25/2021] [Indexed: 01/20/2023] Open
Abstract
Copy number variations (CNV) involving multiple genes are ideal models to study polygenic neuropsychiatric disorders. Since 22q11.2 deletion is regarded as the most important single genetic risk factor for developing schizophrenia, characterizing the effects of this CNV on neural networks offers a unique avenue towards delineating polygenic interactions conferring risk for the disorder. We used a Df(h22q11)/+ mouse model of human 22q11.2 deletion to dissect gene expression patterns that would spatially overlap with differential resting-state functional connectivity (FC) patterns in this model (N = 12 Df(h22q11)/+ mice, N = 10 littermate controls). To confirm the translational relevance of our findings, we analyzed tissue samples from schizophrenia patients and healthy controls using machine learning to explore whether identified genes were co-expressed in humans. Additionally, we employed the STRING protein-protein interaction database to identify potential interactions between genes spatially associated with hypo- or hyper-FC. We found significant associations between differential resting-state connectivity and spatial gene expression patterns for both hypo- and hyper-FC. Two genes, Comt and Trmt2a, were consistently over-expressed across all networks. An analysis of human datasets pointed to a disrupted co-expression of these two genes in the brain in schizophrenia patients, but not in healthy controls. Our findings suggest that COMT and TRMT2A form a core genetic component implicated in differential resting-state connectivity patterns in the 22q11.2 deletion. A disruption of their co-expression in schizophrenia patients points out a prospective cause for the aberrance of brain networks communication in 22q11.2 deletion syndrome on a molecular level.
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Affiliation(s)
- Natalia Gass
- Department of Neuroimaging, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Germany
| | - Zeru Peterson
- Department of Neuroscience and Pharmacology, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Jonathan Reinwald
- Department of Neuroimaging, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Germany; Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Germany
| | - Alexander Sartorius
- Department of Neuroimaging, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Germany; Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Germany
| | - Wolfgang Weber-Fahr
- Department of Neuroimaging, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Germany
| | - Markus Sack
- Department of Neuroimaging, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Germany
| | - Junfang Chen
- Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Germany
| | - Han Cao
- Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Germany
| | | | | | - Gabrielle Klemme
- Department of Neuroscience and Pharmacology, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Adam J Schwarz
- Takeda Pharmaceuticals, Cambridge, MA, USA; Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, USA; Department of Radiology and Imaging Sciences, Indiana University, Indianapolis, IN, USA
| | - Emanuel Schwarz
- Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Germany
| | - Andreas Meyer-Lindenberg
- Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Germany
| | - Thomas Nickl-Jockschat
- Department of Neuroscience and Pharmacology, Carver College of Medicine, University of Iowa, Iowa City, IA, USA; Department of Neuroscience and Pharmacology, Carver College of Medicine, University of Iowa, Iowa City, IA, USA.
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Taylor JA, Larsen KM, Dzafic I, Garrido MI. Predicting subclinical psychotic-like experiences on a continuum using machine learning. Neuroimage 2021; 241:118329. [PMID: 34302968 DOI: 10.1016/j.neuroimage.2021.118329] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 07/01/2021] [Indexed: 11/18/2022] Open
Abstract
Previous studies applying machine learning methods to psychosis have primarily been concerned with the binary classification of chronic schizophrenia patients and healthy controls. The aim of this study was to use electroencephalographic (EEG) data and pattern recognition to predict subclinical psychotic-like experiences on a continuum between these two extremes in otherwise healthy people. We applied two different approaches to an auditory oddball regularity learning task obtained from N = 73 participants: A feature extraction and selection routine incorporating behavioural measures, event-related potential components and effective connectivity parameters; Regularisation of spatiotemporal maps of event-related potentials. Using the latter approach, optimal performance was achieved using the response to frequent, predictable sounds. Features within the P50 and P200 time windows had the greatest contribution toward lower Prodromal Questionnaire (PQ) scores and the N100 time window contributed most to higher PQ scores. As a proof-of-concept, these findings demonstrate that EEG data alone are predictive of individual psychotic-like experiences in healthy people. Our findings are in keeping with the mounting evidence for altered sensory responses in schizophrenia, as well as the notion that psychosis may exist on a continuum expanding into the non-clinical population.
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Affiliation(s)
- Jeremy A Taylor
- Melbourne School of Psychological Sciences, University of Melbourne, Australia; Queensland Brain Institute, University of Queensland, Australia.
| | - Kit Melissa Larsen
- Queensland Brain Institute, University of Queensland, Australia; Australian Research Council Centre of Excellence for Integrative Brain Function; Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital - Amager and Hvidovre, Copenhagen, Denmark; Child and Adolescent Mental Health Care, Mental Health Services Capital Region Copenhagen, University of Copenhagen, Denmark
| | - Ilvana Dzafic
- Melbourne School of Psychological Sciences, University of Melbourne, Australia; Queensland Brain Institute, University of Queensland, Australia; Australian Research Council Centre of Excellence for Integrative Brain Function; Centre for Advanced Imaging, University of Queensland, Australia
| | - Marta I Garrido
- Melbourne School of Psychological Sciences, University of Melbourne, Australia; Queensland Brain Institute, University of Queensland, Australia; Australian Research Council Centre of Excellence for Integrative Brain Function; Centre for Advanced Imaging, University of Queensland, Australia
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Dzafic I, Larsen KM, Darke H, Pertile H, Carter O, Sundram S, Garrido MI. Stronger Top-Down and Weaker Bottom-Up Frontotemporal Connections During Sensory Learning Are Associated With Severity of Psychotic Phenomena. Schizophr Bull 2021; 47:1039-1047. [PMID: 33404057 PMCID: PMC8266649 DOI: 10.1093/schbul/sbaa188] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Recent theories in computational psychiatry propose that unusual perceptual experiences and delusional beliefs may emerge as a consequence of aberrant inference and disruptions in sensory learning. The current study investigates these theories and examines the alterations that are specific to schizophrenia spectrum disorders vs those that occur as psychotic phenomena intensify, regardless of diagnosis. We recruited 66 participants: 22 schizophrenia spectrum inpatients, 22 nonpsychotic inpatients, and 22 nonclinical controls. Participants completed the reversal oddball task with volatility manipulated. We recorded neural responses with electroencephalography and measured behavioral errors to inferences on sound probabilities. Furthermore, we explored neural dynamics using dynamic causal modeling (DCM). Attenuated prediction errors (PEs) were specifically observed in the schizophrenia spectrum, with reductions in mismatch negativity in stable, and P300 in volatile, contexts. Conversely, aberrations in connectivity were observed across all participants as psychotic phenomena increased. DCM revealed that impaired sensory learning behavior was associated with decreased intrinsic connectivity in the left primary auditory cortex and right inferior frontal gyrus (IFG); connectivity in the latter was also reduced with greater severity of psychotic experiences. Moreover, people who experienced more hallucinations and psychotic-like symptoms had decreased bottom-up and increased top-down frontotemporal connectivity, respectively. The findings provide evidence that reduced PEs are specific to the schizophrenia spectrum, but deficits in brain connectivity are aligned on the psychosis continuum. Along the continuum, psychotic experiences were related to an aberrant interplay between top-down, bottom-up, and intrinsic connectivity in the IFG during sensory uncertainty. These findings provide novel insights into psychosis neurocomputational pathophysiology.
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Affiliation(s)
- Ilvana Dzafic
- Department of Medicine, Dentistry & Health Sciences, Melbourne School of Psychological Sciences, University of Melbourne, Melbourne, VIC, Australia.,Queensland Brain Institute, University of Queensland, Brisbane, QLD, Australia.,Australian Research Council Centre of Excellence for Integrative Brain Function, Melbourne, Australia.,Centre for Advanced Imaging, University of Queensland, Brisbane, QLD, Australia
| | - Kit M Larsen
- Queensland Brain Institute, University of Queensland, Brisbane, QLD, Australia.,Australian Research Council Centre of Excellence for Integrative Brain Function, Melbourne, Australia.,Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark.,Child and Adolescent Mental Health Centre, Mental Health Services Capital Region Copenhagen, University of Copenhagen, Copenhagen, Denmark
| | - Hayley Darke
- Department of Medicine, Dentistry & Health Sciences, Melbourne School of Psychological Sciences, University of Melbourne, Melbourne, VIC, Australia.,Department of Psychiatry, School of Clinical Sciences, Monash University, Melbourne, VIC, Australia
| | - Holly Pertile
- Department of Psychiatry, School of Clinical Sciences, Monash University, Melbourne, VIC, Australia.,Monash Medical Centre, Monash Health, Clayton, VIC, Australia
| | - Olivia Carter
- Department of Medicine, Dentistry & Health Sciences, Melbourne School of Psychological Sciences, University of Melbourne, Melbourne, VIC, Australia
| | - Suresh Sundram
- Department of Psychiatry, School of Clinical Sciences, Monash University, Melbourne, VIC, Australia.,Monash Medical Centre, Monash Health, Clayton, VIC, Australia
| | - Marta I Garrido
- Department of Medicine, Dentistry & Health Sciences, Melbourne School of Psychological Sciences, University of Melbourne, Melbourne, VIC, Australia.,Queensland Brain Institute, University of Queensland, Brisbane, QLD, Australia.,Australian Research Council Centre of Excellence for Integrative Brain Function, Melbourne, Australia.,Centre for Advanced Imaging, University of Queensland, Brisbane, QLD, Australia
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Cantonas LM, Mancini V, Rihs TA, Rochas V, Schneider M, Eliez S, Michel CM. Abnormal Auditory Processing and Underlying Structural Changes in 22q11.2 Deletion Syndrome. Schizophr Bull 2020; 47:189-196. [PMID: 32747926 PMCID: PMC7825015 DOI: 10.1093/schbul/sbaa104] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The 22q11.2 deletion syndrome (22q11.2 DS), one of the highest genetic risk for the development of schizophrenia, offers a unique opportunity to understand neurobiological and functional changes preceding the onset of the psychotic illness. Reduced auditory mismatch negativity response (MMN) has been proposed as a promising index of abnormal sensory processing and brain pathology in schizophrenia. However, the link between the MMN response and its underlying cerebral mechanisms in 22q11.2 DS remains unexamined. We measured auditory-evoked potentials to frequency deviant stimuli with high-density electroencephalogram and volumetric estimates of cortical and thalamic auditory areas with structural T1-weighted magnetic resonance imaging in a sample of 130 individuals, 70 with 22q11.2 DS and 60 age-matched typically developing (TD) individuals. Compared to TD group, the 22q11.2 deletion carriers reveal reduced MMN response and significant changes in topographical maps and decreased gray matter volumes of cortical and subcortical auditory areas, however, without any correlations between MMN alteration and structural changes. Furthermore, exploratory research on the presence of hallucinations (H+\H-) reveals no change in MMN response in 22q11.2DS (H+ and H-) as compared to TD individuals. Nonetheless, we observe bilateral volume reduction of the superior temporal gyrus and left medial geniculate in 22q11.2DSH+ as compared to 22q11.2DSH- and TD participants. These results suggest that the mismatch response might be a promising neurophysiological marker of functional changes within the auditory pathways that might underlie elevated risk for the development of psychotic symptoms.
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Affiliation(s)
- Lucia-Manuela Cantonas
- Functional Brain Mapping Laboratory, Department of Basic Neuroscience, University of Geneva, Geneva, Switzerland,To whom correspondence should be addressed; tel: 0041 (0) 22 37 908 88, e-mail:
| | - Valentina Mancini
- Developmental Imaging and Psychopathology Lab, Department of Psychiatry, University of Geneva, Geneva, Switzerland
| | - Tonia A Rihs
- Functional Brain Mapping Laboratory, Department of Basic Neuroscience, University of Geneva, Geneva, Switzerland
| | - Vincent Rochas
- Functional Brain Mapping Laboratory, Department of Basic Neuroscience, University of Geneva, Geneva, Switzerland
| | - Maude Schneider
- Developmental Imaging and Psychopathology Lab, Department of Psychiatry, University of Geneva, Geneva, Switzerland,Clinical Psychology Unit for Intellectual and Developmental Disabilities, Faculty of Psychology and Educational Sciences, University of Geneva, Geneva, Switzerland
| | - Stephan Eliez
- Developmental Imaging and Psychopathology Lab, Department of Psychiatry, University of Geneva, Geneva, Switzerland,Department of Genetic Medicine and Development, University of Geneva School of Medicine, Geneva, Switzerland,Fondation Pôle Autisme, Geneva, Switzerland
| | - Christoph M Michel
- Functional Brain Mapping Laboratory, Department of Basic Neuroscience, University of Geneva, Geneva, Switzerland,EEG Brain Mapping Core, Center for Biomedical Imaging of Lausanne and Geneva, Geneva, Switzerland
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Larsen KM, Dzafic I, Darke H, Pertile H, Carter O, Sundram S, Garrido MI. Aberrant connectivity in auditory precision encoding in schizophrenia spectrum disorder and across the continuum of psychotic-like experiences. Schizophr Res 2020; 222:185-194. [PMID: 32593736 DOI: 10.1016/j.schres.2020.05.061] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 05/11/2020] [Accepted: 05/27/2020] [Indexed: 11/24/2022]
Abstract
BACKGROUND The ability to generate a precise internal model of statistical regularities is impaired in schizophrenia. Predictive coding accounts of schizophrenia suggest that psychotic symptoms may be explained by a failure to build precise beliefs or a model of the world. The precision of this model may vary with context. For example, in a noisy environment the model will be more imprecise compared to a model built in an environment with lower noise. However compelling, this idea has not yet been empirically studied in schizophrenia. METHODS In this study, 62 participants engaged in a stochastic mismatch negativity paradigm with high and low precision. We included inpatients with a schizophrenia spectrum disorder (N = 20), inpatients with a psychiatric disorder but without psychosis (N = 20), and healthy controls (N = 22), with comparable sex ratio and age distribution. Bayesian mapping and dynamic causal modelling were employed to investigate the underlying microcircuitry of precision encoding of auditory stimuli. RESULTS We found strong evidence (exceedance P > 0.99) for differences in the underlying connectivity associated with precision encoding between the three groups as well as on the continuum of psychotic-like experiences assessed across all participants. Critically, we show changes in interhemispheric connectivity between the two inpatient groups, with some connections further aligning on the continuum of psychotic-like experiences. CONCLUSIONS While our results suggest continuity in backward connectivity alterations with psychotic-like experiences regardless of diagnosis, they also point to specificity for the schizophrenia spectrum disorder group in interhemispheric connectivity alterations.
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Affiliation(s)
- Kit Melissa Larsen
- Queensland Brain Institute, The University of Queensland, Australia; Australian Research Council of Excellence for Integrative Brain Function, Australia; Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark; Child and Adolescent Mental Health Centre, Mental Health Services Capital Region Copenhagen, University of Copenhagen, Denmark.
| | - Ilvana Dzafic
- Queensland Brain Institute, The University of Queensland, Australia; Australian Research Council of Excellence for Integrative Brain Function, Australia; Melbourne School of Psychological Sciences, University of Melbourne, Australia
| | - Hayley Darke
- Melbourne School of Psychological Sciences, University of Melbourne, Australia
| | - Holly Pertile
- Department of Psychiatry, School of Clinical Sciences, Monash University, Clayton, VIC, Australia; Monash Medical Centre, Monash Health, Clayton, VIC, Australia
| | - Olivia Carter
- Melbourne School of Psychological Sciences, University of Melbourne, Australia
| | - Suresh Sundram
- Department of Psychiatry, School of Clinical Sciences, Monash University, Clayton, VIC, Australia; Monash Medical Centre, Monash Health, Clayton, VIC, Australia
| | - Marta I Garrido
- Queensland Brain Institute, The University of Queensland, Australia; Australian Research Council of Excellence for Integrative Brain Function, Australia; Melbourne School of Psychological Sciences, University of Melbourne, Australia; Centre for Advanced Imaging, The University of Queensland, Australia
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Francisco AA, Foxe JJ, Horsthuis DJ, DeMaio D, Molholm S. Assessing auditory processing endophenotypes associated with Schizophrenia in individuals with 22q11.2 deletion syndrome. Transl Psychiatry 2020; 10:85. [PMID: 32139692 PMCID: PMC7058163 DOI: 10.1038/s41398-020-0764-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Accepted: 02/21/2020] [Indexed: 12/19/2022] Open
Abstract
22q11.2 Deletion Syndrome (22q11.2DS) is the strongest known molecular risk factor for schizophrenia. Brain responses to auditory stimuli have been studied extensively in schizophrenia and described as potential biomarkers of vulnerability to psychosis. We sought to understand whether these responses might aid in differentiating individuals with 22q11.2DS as a function of psychotic symptoms, and ultimately serve as signals of risk for schizophrenia. A duration oddball paradigm and high-density electrophysiology were used to test auditory processing in 26 individuals with 22q11.2DS (13-35 years old, 17 females) with varying degrees of psychotic symptomatology and in 26 age- and sex-matched neurotypical controls (NT). Presentation rate varied across three levels, to examine the effect of increasing demands on memory and the integrity of sensory adaptation. We tested whether N1 and mismatch negativity (MMN), typically reduced in schizophrenia, related to clinical/cognitive measures, and how they were affected by presentation rate. N1 adaptation effects interacted with psychotic symptomatology: Compared to an NT group, individuals with 22q11.2DS but no psychotic symptomatology presented larger adaptation effects, whereas those with psychotic symptomatology presented smaller effects. In contrast, individuals with 22q11.2DS showed increased effects of presentation rate on MMN amplitude, regardless of the presence of symptoms. While IQ and working memory were lower in the 22q11.2DS group, these measures did not correlate with the electrophysiological data. These findings suggest the presence of two distinct mechanisms: One intrinsic to 22q11.2DS resulting in increased N1 and MMN responses; another related to psychosis leading to a decreased N1 response.
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Affiliation(s)
- Ana A Francisco
- The Cognitive Neurophysiology Laboratory, Department of Pediatrics, Albert Einstein College of Medicine, Bronx, NY, USA
- Department of Neuroscience, Rose F. Kennedy Center, Albert Einstein College of Medicine, Bronx, NY, USA
| | - John J Foxe
- The Cognitive Neurophysiology Laboratory, Department of Pediatrics, Albert Einstein College of Medicine, Bronx, NY, USA
- Department of Neuroscience, Rose F. Kennedy Center, Albert Einstein College of Medicine, Bronx, NY, USA
- The Cognitive Neurophysiology Laboratory, Department of Neuroscience, The Ernest J. Del Monde Institute for Neuroscience, School of Medicine and Dentistry, University of Rochester, Rochester, NY, USA
| | - Douwe J Horsthuis
- The Cognitive Neurophysiology Laboratory, Department of Pediatrics, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Danielle DeMaio
- The Cognitive Neurophysiology Laboratory, Department of Pediatrics, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Sophie Molholm
- The Cognitive Neurophysiology Laboratory, Department of Pediatrics, Albert Einstein College of Medicine, Bronx, NY, USA.
- Department of Neuroscience, Rose F. Kennedy Center, Albert Einstein College of Medicine, Bronx, NY, USA.
- The Cognitive Neurophysiology Laboratory, Department of Neuroscience, The Ernest J. Del Monde Institute for Neuroscience, School of Medicine and Dentistry, University of Rochester, Rochester, NY, USA.
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10
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Porthole and Stormcloud: Tools for Visualisation of Spatiotemporal M/EEG Statistics. Neuroinformatics 2020; 18:351-363. [DOI: 10.1007/s12021-019-09447-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Oestreich LKL, Randeniya R, Garrido MI. Auditory prediction errors and auditory white matter microstructure associated with psychotic-like experiences in healthy individuals. Brain Struct Funct 2019; 224:3277-3289. [PMID: 31686202 DOI: 10.1007/s00429-019-01972-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Accepted: 10/17/2019] [Indexed: 12/23/2022]
Abstract
Our sensory systems actively predict sensory information based on previously learnt patterns, which are continuously updated with information from the actual sensory input via prediction errors. Individuals with schizophrenia consistently show reduced auditory prediction errors as well as altered fractional anisotropy (indicative of white matter changes) in the arcuate fasciculus and the auditory interhemispheric pathway, both of which are auditory white matter pathways associated with prediction errors. However, it is not clear if healthy individuals with psychotic-like experiences exhibit similar deficits. Participants underwent electroencephalography (EEG) recordings while listening to a classical two-tone duration deviant oddball paradigm (n = 103) and a stochastic oddball paradigm (n = 89). A subset of participants (n = 89) also underwent diffusion-weighted magnetic resonance imaging (MRI). Fractional anisotropy (FA), was extracted from the arcuate fasciculi and the auditory interhemispheric pathway. While prediction errors evoked by the classical oddball paradigm failed to reveal significant effects, the stochastic oddball paradigm elicited significant clusters at the typical mismatch negativity time window. Furthermore, we observed that FA of the arcuate fasciculi and auditory interhemispheric pathway significantly improved predictive models of psychotic-like experiences in healthy individuals over and above predictions made by auditory prediction error responses alone. Specifically, we observed that decreasing FA in the auditory interhemispheric pathway and reducing ability to learn stochastic irregularities are associated with increasing CAPE + scores. To the extent that these associations have previously been reported in patients with schizophrenia, the findings from this study suggest that both, auditory prediction errors and white matter changes in the auditory interhemispheric pathway, may have the potential to be translated into early screening markers for psychosis.
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Affiliation(s)
- L K L Oestreich
- UQ Centre for Clinical Research, The University of Queensland, Brisbane, Australia. .,Centre for Advanced Imaging, The University of Queensland, Brisbane, Australia. .,Royal Brisbane and Women's Hospital, Brisbane, Australia.
| | - R Randeniya
- Queensland Brain Institute, The University of Queensland, Brisbane, Australia.,ARC Centre for Integrative Brain Function, Clayton, Australia
| | - M I Garrido
- Centre for Advanced Imaging, The University of Queensland, Brisbane, Australia.,Queensland Brain Institute, The University of Queensland, Brisbane, Australia.,Melbourne School of Psychological Sciences, The University of Melbourne, Melbourne, Australia.,ARC Centre for Integrative Brain Function, Clayton, Australia
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12
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Abnormal development of early auditory processing in 22q11.2 Deletion Syndrome. Transl Psychiatry 2019; 9:138. [PMID: 30992427 PMCID: PMC6467880 DOI: 10.1038/s41398-019-0473-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 01/25/2019] [Accepted: 03/23/2019] [Indexed: 12/12/2022] Open
Abstract
The 22q11.2 Deletion Syndrome (22q11.2 DS) is one of the highest genetic risk factors for the development of schizophrenia spectrum disorders. In schizophrenia, reduced amplitude of the frequency mismatch negativity (fMMN) has been proposed as a promising neurophysiological marker for progressive brain pathology. In this longitudinal study in 22q11.2 DS, we investigate the progression of fMMN between childhood and adolescence, a vulnerable period for brain maturation. We measured evoked potentials to auditory oddball stimuli in the same sample of 16 patients with 22q11.2 DS and 14 age-matched controls in childhood and adolescence. In addition, we cross-sectionally compared an increased sample of 51 participants with 22q11.2 DS and 50 controls divided into two groups (8-14 and 14-20 years). The reported results are obtained using the fMMN difference waveforms. In the longitudinal design, the 22q11.2 deletion carriers exhibit a significant reduction in amplitude and a change in topographic patterns of the mismatch negativity response from childhood to adolescence. The same effect, reduced mismatch amplitude in adolescence, while preserved during childhood, is observed in the cross-sectional study. These results point towards functional changes within the brain network responsible for the fMMN. In addition, the adolescents with 22q11.2 DS displayed a significant increase in amplitude over central electrodes during the auditory N1 component. No such differences, reduced mismatch response nor increased N1, were observed in the typically developing group. These findings suggest different developmental trajectories of early auditory sensory processing in 22q11.2 DS and functional changes that emerge during the critical period of increased risk for schizophrenia spectrum disorders.
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13
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Larsen KM, Dzafic I, Siebner HR, Garrido MI. Alteration of functional brain architecture in 22q11.2 deletion syndrome – Insights into susceptibility for psychosis. Neuroimage 2019; 190:154-171. [DOI: 10.1016/j.neuroimage.2018.09.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 08/30/2018] [Accepted: 09/02/2018] [Indexed: 12/23/2022] Open
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14
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Larsen KM, Mørup M, Birknow MR, Fischer E, Olsen L, Didriksen M, Baaré WFC, Werge TM, Garrido MI, Siebner HR. Individuals with 22q11.2 deletion syndrome show intact prediction but reduced adaptation in responses to repeated sounds: Evidence from Bayesian mapping. Neuroimage Clin 2019; 22:101721. [PMID: 30785050 PMCID: PMC6383326 DOI: 10.1016/j.nicl.2019.101721] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 01/23/2019] [Accepted: 02/12/2019] [Indexed: 01/22/2023]
Abstract
One of the most common copy number variants, the 22q11.2 microdeletion, confers an increased risk for schizophrenia. Since schizophrenia has been associated with an aberrant neural response to repeated stimuli through both reduced adaptation and prediction, we here hypothesized that this may also be the case in nonpsychotic individuals with a 22q11.2 deletion. We recorded high-density EEG from 19 individuals with 22q11.2 deletion syndrome (12-25 years), as well as 27 healthy volunteers with comparable age and sex distribution, while they listened to a sequence of sounds arranged in a roving oddball paradigm. Using posterior probability maps and dynamic causal modelling we tested three different models accounting for repetition dependent changes in cortical responses as well as in effective connectivity; namely an adaptation model, a prediction model, and a model including both adaptation and prediction. Repetition-dependent changes were parametrically modulated by a combination of adaptation and prediction and were apparent in both cortical responses and in the underlying effective connectivity. This effect was reduced in individuals with a 22q11.2 deletion and was negatively correlated with negative symptom severity. Follow-up analysis showed that the reduced effect of the combined adaptation and prediction model seen in individuals with 22q11.2 deletion was driven by reduced adaptation rather than prediction failure. Our findings suggest that adaptation is reduced in individuals with a 22q11.2 deletion, which can be interpreted in light of the framework of predictive coding as a failure to suppress prediction errors.
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Affiliation(s)
- Kit Melissa Larsen
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark; DTU Compute, Cognitive Systems, Technical University of Denmark, Lyngby, Denmark; Institute of Biological Psychiatry, Mental Health Centre Sct. Hans, Copenhagen University Hospital, Boserupvej 2, DK-4000 Roskilde, Denmark; iPSYCH, The Lundbeck Foundation Initiative for Integrative Psychiatric Research, Aarhus and Copenhagen, Denmark; Queensland Brain Institute, The University of Queensland, St Lucia, 4072 Brisbane, Australia.
| | - Morten Mørup
- DTU Compute, Cognitive Systems, Technical University of Denmark, Lyngby, Denmark
| | - Michelle Rosgaard Birknow
- Institute of Biological Psychiatry, Mental Health Centre Sct. Hans, Copenhagen University Hospital, Boserupvej 2, DK-4000 Roskilde, Denmark; iPSYCH, The Lundbeck Foundation Initiative for Integrative Psychiatric Research, Aarhus and Copenhagen, Denmark; Synaptic Transmission, H. Lundbeck A/S, Ottiliavej 9, DK-2500, Valby, Denmark
| | - Elvira Fischer
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
| | - Line Olsen
- Institute of Biological Psychiatry, Mental Health Centre Sct. Hans, Copenhagen University Hospital, Boserupvej 2, DK-4000 Roskilde, Denmark; iPSYCH, The Lundbeck Foundation Initiative for Integrative Psychiatric Research, Aarhus and Copenhagen, Denmark
| | - Michael Didriksen
- Synaptic Transmission, H. Lundbeck A/S, Ottiliavej 9, DK-2500, Valby, Denmark
| | - William Frans Christiaan Baaré
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
| | - Thomas Mears Werge
- Institute of Biological Psychiatry, Mental Health Centre Sct. Hans, Copenhagen University Hospital, Boserupvej 2, DK-4000 Roskilde, Denmark; iPSYCH, The Lundbeck Foundation Initiative for Integrative Psychiatric Research, Aarhus and Copenhagen, Denmark; Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Marta Isabel Garrido
- Queensland Brain Institute, The University of Queensland, St Lucia, 4072 Brisbane, Australia; Centre for Advanced Imaging, The University of Queensland, St Lucia, 4072 Brisbane, Australia; Australian Research Council Centre of Excellence for Integrative Brain Function Centre of Excellence for Integrative Brain Function, The University of Queensland, St Lucia, 4072 Brisbane, Australia; School of Mathematics and Physics, The University of Queensland, St Lucia, 4072 Brisbane, Australia
| | - Hartwig Roman Siebner
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark; Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Department of Neurology, Copenhagen University Hospital Bispebjerg, Copenhagen, Denmark
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15
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Gao L, Tang SX, Yi JJ, McDonald-McGinn DM, Zackai EH, Emanuel BS, Gur RC, Calkins ME, Gur RE. Musical auditory processing, cognition, and psychopathology in 22q11.2 deletion syndrome. Am J Med Genet B Neuropsychiatr Genet 2018; 177:765-773. [PMID: 30444066 DOI: 10.1002/ajmg.b.32690] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 07/20/2018] [Accepted: 09/26/2018] [Indexed: 11/11/2022]
Abstract
Chromosome 22q11.2 deletion syndrome (22q11DS) is associated with impairment in multiple domains of cognition and risk for several psychiatric disorders. Musical auditory processing is highly heritable, and is impaired in individuals with schizophrenia and other neurodevelopmental disorders, but has never been studied in 22q11DS, notwithstanding anecdotal evidence of its sparing. We aimed to characterize musical auditory processing in 22q11DS and explore potential relationships with other cognitive domains, musical engagement, and psychiatric disorders. The Distorted Tunes Task and Global Musical Sophistication Index were used to assess pitch discrimination and general musical engagement in 58 individuals with 22q11DS aged 8-29 years. Psychopathology was assessed with sections from the modified Schedule for Affective Disorders and Schizophrenia for School-Age Children and the Structured Interview for Prodromal Syndromes. The Penn computerized neurocognitive battery (CNB) examined four domains of cognition (executive functioning, episodic memory, complex cognition, and social cognition). Significant musical auditory processing impairment and reduced musical engagement were found in individuals with 22q11DS. However, deficits in musical auditory processing were not associated with reduced musical engagement. After covarying for age and sex, episodic memory and overall CNB performance accuracy were significantly related to performance in musical auditory processing. There were no relationships between musical auditory processing and presence of any psychiatric diagnoses. Individuals with 22q11DS experience significant deficits in musical auditory processing and reduced musical engagement. Pitch discrimination is associated with overall cognitive ability, but appears to be largely independent of psychiatric illness.
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Affiliation(s)
- Lucy Gao
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Sunny X Tang
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - James J Yi
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Donna M McDonald-McGinn
- Division of Human Genetics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania.,Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Elaine H Zackai
- Division of Human Genetics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania.,Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Beverly S Emanuel
- Division of Human Genetics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania.,Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Ruben C Gur
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Monica E Calkins
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Raquel E Gur
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Psychiatry, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
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16
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Abstract
Recent large-scale genomic studies have confirmed that schizophrenia is a polygenic syndrome and have implicated a number of biological pathways in its aetiology. Both common variants individually of small effect and rarer but more penetrant genetic variants have been shown to play a role in the pathogenesis of the disorder. No simple Mendelian forms of the condition have been identified, but progress has been made in stratifying risk on the basis of the polygenic burden of common variants individually of small effect, and the contribution of rarer variants of larger effect such as Copy Number Variants (CNVs). Pathway analysis of risk-associated variants has begun to identify specific biological processes implicated in risk for the disorder, including elements of the glutamatergic NMDA receptor complex and post synaptic density, voltage-gated calcium channels, targets of the Fragile X Mental Retardation Protein (FMRP targets) and immune pathways. Genetic studies have also been used to drive genomic imaging approaches to the investigation of brain markers associated with risk for the disorder. Genomic imaging approaches have been applied both to investigate the effect of polygenic risk and to study the impact of individual higher-penetrance variants such as CNVs. Both genomic and genomic imaging approaches offer potential for the stratification of patients and at-risk groups and the development of better biomarkers of risk and treatment response; however, further research is needed to integrate this work and realise the full potential of these approaches.
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