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From communication dysfunction to treatment options in serious mental illness. Psychiatry Res 2023; 321:115062. [PMID: 36746033 DOI: 10.1016/j.psychres.2023.115062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 01/12/2023] [Accepted: 01/14/2023] [Indexed: 01/21/2023]
Abstract
The Commentary covers research focused on language dysfunction in schizophrenia, and more broadly in communication dysfunction in this disorder, which I have examined with a variety of both behavioral and imaging methodologies. It briefly outlines how further progress can be achieved in pursuing the goal of a comprehensive understanding of its underlying causes. Possible therapeutic approaches are also briefly discussed.
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van der Merwe J, Biagio-de Jager L, Mahomed-Asmail F, Hall JW. Documentation of Peripheral Auditory Function in Studies of the Auditory P300 Response. J PSYCHOPHYSIOL 2022. [DOI: 10.1027/0269-8803/a000312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Abstract. A critical review was conducted to examine whether the peripheral hearing status of participants with neurological and psychological disorders was documented in published clinical studies of the auditory P300 response. Literature searches were conducted with three databases: PubMed, PsycINFO, and Scopus. Studies of participants with seven neurological or psychological disorders were included in the study. Each disorder was coupled with the main search phrase in separate searches on each database. Of the total 102 papers which met the inclusion criteria, the majority (64%) did not describe the peripheral hearing sensitivity of participants. In this review with studies that included participants at risk for hearing impairment, particularly age-related hearing loss, only a single publication adequately described formal hearing evaluation. Peripheral hearing status is rarely defined in studies of the P300 response. The inclusion of participants with a hearing loss likely affects the validity of findings for these studies. We recommend formal hearing assessment prior to inclusion of participants in studies of the auditory P300 response. The findings of this study may increase the awareness among researchers outside the field of audiology of the effects of peripheral hearing loss on the auditory P300.
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Affiliation(s)
- Janushca van der Merwe
- Department of Speech Language Pathology and Audiology, University of Pretoria, South Africa
| | - Leigh Biagio-de Jager
- Department of Speech Language Pathology and Audiology, University of Pretoria, South Africa
| | - Faheema Mahomed-Asmail
- Department of Speech Language Pathology and Audiology, University of Pretoria, South Africa
- Virtual Hearing Lab, Collaborative Initiative between University of Colorado and the University of Pretoria, Aurora, CO, USA
| | - James W. Hall
- Department of Speech Language Pathology and Audiology, University of Pretoria, South Africa
- George Osborne College of Audiology, Salus University, Elkins Park, PA, USA
- Department of Communication Science and Disorders, University of Hawaii, Honolulu, HI, USA
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3
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Semantic processing features and schizotypal traits: A test-retest study. Int J Psychophysiol 2022; 178:1-8. [DOI: 10.1016/j.ijpsycho.2022.06.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 05/30/2022] [Accepted: 06/02/2022] [Indexed: 11/18/2022]
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4
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Siddiqui SV, Nizamie SH, Siddiqui MA, Jahan M, Garg S, Tikka SK, Shreekantiah U. Evaluation of N-400 Evoked Response Potential in schizophrenia: An endophenotype or a disease marker? Psychiatry Res 2021; 300:113907. [PMID: 33839423 DOI: 10.1016/j.psychres.2021.113907] [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] [Received: 05/16/2020] [Accepted: 03/27/2021] [Indexed: 01/07/2023]
Abstract
N400 evoked response potentials (ERP) reliably map key semantic deficits in schizophrenia. Assessing them as endophenotypes might help in better understanding of schizophrenia risk and their use as biomarkers. We aimed to study N400 as an endophenotype marker by comparing schizophrenia (SCZ), unaffected first-degree relatives (FDR) and healthy controls (HC) and, by assessing its ability to discriminate these groups. Drug naïve or free SCZ probands (n=30), their unaffected FDRs (n=30) and HC (n=30), underwent a 40-channel ERP recording while performing a custom-made, Hindi- sentence context paradigm task, containing congruent and incongruent conditions. Fifteen centro-parietal (CP) leads, further classified into three regions-midline (CPM), right (CPR) and left (CPL) were selected as electrodes-of-interest for assessing N400. During the incongruent condition, compared to both FDRs and HC, SCZ showed significantly longer N400 latency, at CPM, CPR and CPL, and significantly lesser (more negative) amplitude, at CPM; no significant difference was noted between FDR and HC groups. On discriminant functional analysis, significant N400 predictors could accurately classify 73.3% SCZ from HC and 75% of SCZ from FDR. We conclude that N400 deficits, elicited by the incongruent condition of the sentence task, could be potential biomarkers to define disease state in schizophrenia; they may not be endophenotype markers.
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Affiliation(s)
- Shazia Veqar Siddiqui
- Dr Shazia Veqar Siddiqui, Ph.D., M.Phil. Consultant Clinical Psychologist Healthy Minds, Lucknow, UP, India
| | - S Haque Nizamie
- Dr S-Haque Nizamie, M.D., D.P.M. Consultant Psychiatrist, Ex-Director Central Institute of Ranchi, Ranchi, India
| | - M Aleem Siddiqui
- Dr Mohd Aleem Siddiqui, M.D., D.P.M, Professor, Era's Lucknow Medical College and Hospital, UP, India
| | - Masroor Jahan
- Dr. Masroor Jahan, Ph.D., M.Phil. Additional Professor, Department of Psychology, RINPAS, Ranchi, India
| | - Shobit Garg
- Shobit Garg, M.D., D.P.M. Associate Professor, Department of Psychiatry, Shri Guru Ram Rai Institute of Medical and Health Sciences, 248001, Uttarakhand, India.
| | - Sai Krishna Tikka
- Sai Krishna Tikka, M.D., D.P.M. Associate Professor, Department of Psychiatry, All India Institute of Medical Sciences (AIIMS), Bibinagar, India
| | - Umesh Shreekantiah
- Umesh S., M.D., D.P.M. Assistant Professor, Central Institute of Psychiatry, Ranchi
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Hirano S, Spencer KM, Onitsuka T, Hirano Y. Language-Related Neurophysiological Deficits in Schizophrenia. Clin EEG Neurosci 2020; 51:222-233. [PMID: 31741393 DOI: 10.1177/1550059419886686] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Schizophrenia is a severe psychiatric disorder that affects all aspects of one's life with several cognitive and social dysfunctions. However, there is still no objective and universal index for diagnosis and treatment of this disease. Many researchers have studied language processing in schizophrenia since most of the patients show symptoms related to language processing, such as thought disorder, auditory verbal hallucinations, or delusions. Electroencephalography (EEG) and magnetoencephalography (MEG) with millisecond order high temporal resolution, have been applied to reveal the abnormalities in language processing in schizophrenia. The aims of this review are (a) to provide an overview of recent findings in language processing in schizophrenia with EEG and MEG using neurophysiological indices, providing insights into underlying language related pathophysiological deficits in this disease and (b) to emphasize the advantage of EEG and MEG in research on language processing in schizophrenia.
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Affiliation(s)
- Shogo Hirano
- Department of Neuropsychiatry, Graduate School of Medical Sciences, Kyushu University, Higashiku, Fukuoka, Japan.,Neural Dynamics Laboratory, Research Service, VA Boston Healthcare System, and Department of Psychiatry, Harvard Medical School, Boston, MA, USA
| | - Kevin M Spencer
- Neural Dynamics Laboratory, Research Service, VA Boston Healthcare System, and Department of Psychiatry, Harvard Medical School, Boston, MA, USA
| | - Toshiaki Onitsuka
- Department of Neuropsychiatry, Graduate School of Medical Sciences, Kyushu University, Higashiku, Fukuoka, Japan
| | - Yoji Hirano
- Department of Neuropsychiatry, Graduate School of Medical Sciences, Kyushu University, Higashiku, Fukuoka, Japan.,Neural Dynamics Laboratory, Research Service, VA Boston Healthcare System, and Department of Psychiatry, Harvard Medical School, Boston, MA, USA
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6
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The N400 event-related brain potential response: A window on deficits in predicting meaning in schizophrenia. Int J Psychophysiol 2019; 145:65-69. [DOI: 10.1016/j.ijpsycho.2019.04.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 04/08/2019] [Accepted: 04/16/2019] [Indexed: 11/22/2022]
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7
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Gross ME, Araujo DB, Zedelius CM, Schooler JW. Is perception the missing link between creativity, curiosity and schizotypy? Evidence from spontaneous eye-movements and responses to auditory oddball stimuli. Neuroimage 2019; 202:116125. [DOI: 10.1016/j.neuroimage.2019.116125] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 08/01/2019] [Accepted: 08/23/2019] [Indexed: 11/25/2022] Open
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Kelly S, Guimond S, Lyall A, Stone WS, Shenton ME, Keshavan M, Seidman LJ. Neural correlates of cognitive deficits across developmental phases of schizophrenia. Neurobiol Dis 2018; 131:104353. [PMID: 30582983 DOI: 10.1016/j.nbd.2018.12.013] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2018] [Revised: 11/21/2018] [Accepted: 12/20/2018] [Indexed: 12/28/2022] Open
Abstract
Schizophrenia is associated with cognitive deficits across all stages of the illness (i.e., high risk, first episode, early and chronic phases). Identifying the underlying neurobiological mechanisms of these deficits is an important area of scientific inquiry. Here, we selectively review evidence regarding the pattern of deficits across the developmental trajectory of schizophrenia using the five cognitive domains identified by the Research Domain Criteria (RDoC) initiative. We also report associated findings from neuroimaging studies. We suggest that most cognitive domains are affected across the developmental trajectory, with corresponding brain structural and/or functional differences. The idea of a common mechanism driving these deficits is discussed, along with implications for cognitive treatment in schizophrenia.
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Affiliation(s)
- Sinead Kelly
- Massachusetts Mental Health Center, Public Psychiatry Division, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA; Psychiatry Neuroimaging Laboratory, Department of Psychiatry, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Synthia Guimond
- Massachusetts Mental Health Center, Public Psychiatry Division, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA; The Royal's Institute of Mental Health Research, University of Ottawa, Ottawa, ON, Canada
| | - Amanda Lyall
- Psychiatry Neuroimaging Laboratory, Department of Psychiatry, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA; Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - William S Stone
- Massachusetts Mental Health Center, Public Psychiatry Division, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Martha E Shenton
- Psychiatry Neuroimaging Laboratory, Department of Psychiatry, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA; Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA; Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA; VA Boston Healthcare System, Brockton Division, Brockton, MA, USA
| | - Matcheri Keshavan
- Massachusetts Mental Health Center, Public Psychiatry Division, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
| | - Larry J Seidman
- Massachusetts Mental Health Center, Public Psychiatry Division, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA; Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
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Abstract
BackgroundNeurobiological studies of the early course of psychoses, such as schizophrenia, allow investigation of pathophysiology without the confounds of illness chronicity and treatment.AimsTo review the recent literature on the biology of the early course of psychoses.MethodWe carried out a critical appraisal of the recent findings in the neurobiology of early psychoses, using structural, functional and neurochemical imaging techniques.ResultsBrain structural alterations are present early in the illness and may predate symptom onset. Some changes, notably those in frontal and temporal lobes, can progress during the early phases of the illness. Functional and neurochemical brain abnormalities can also be seen in the premorbid and the early phases of the illness. Some, although not all, changes can be trait-like whereas some others might progress during the early years.ConclusionsA better understanding of such changes, especially during the critical periods of the prodrome, around the transition to the psychotic phase and during the early phases of the illness is crucial for continued research into preventive intervention strategies.
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Affiliation(s)
- Matcheri S Keshavan
- Department of Psychiatry and Behavioral Neurosciences, Wayne State University, UCH 9B, 4201 St Antoine Boulevard, Detroit, MI, USA.
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Abnormal N400 Semantic Priming Effect May Reflect Psychopathological Processes in Schizophrenia: A Twin Study. SCHIZOPHRENIA RESEARCH AND TREATMENT 2017; 2017:7163198. [PMID: 28932600 PMCID: PMC5592423 DOI: 10.1155/2017/7163198] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 05/22/2017] [Accepted: 06/13/2017] [Indexed: 12/05/2022]
Abstract
OBJECTIVE Activation of semantic networks is indexed by the N400 effect. We used a twin study design to investigate whether N400 effect abnormalities reflect genetic/trait liability or are related to psychopathological processes in schizophrenia. METHODS We employed robust linear regression to compare N400 and behavioral priming effects across 36 monozygotic twin pairs (6 pairs concordant for schizophrenia/schizoaffective disorder, 11 discordant pairs, and 19 healthy control pairs) performing a lexical decision task. Moreover, we examined the correlation between Brief Psychiatric Rating Scale (BPRS) score and the N400 effect and the influence of medication status on this effect. RESULTS Regression yielded a significant main effect of group on the N400 effect only in the direct priming condition (p = 0.003). Indirect condition and behavioral priming effect showed no significant effect of group. Planned contrasts with the control group as a reference group revealed that affected concordant twins had significantly reduced N400 effect compared to controls, and discordant affected twins had a statistical trend for reduced N400 effect compared to controls. The unaffected twins did not differ significantly from the controls. There was a trend for correlation between reduced N400 effect and higher BPRS scores, and the N400 effect did not differ significantly between medicated and unmedicated patients. CONCLUSIONS Reduced N400 effect may reflect disease-specific processes in schizophrenia implicating frontotemporal brain network in schizophrenia pathology.
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11
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Earls HA, Curran T, Mittal V. A Meta-analytic Review of Auditory Event-Related Potential Components as Endophenotypes for Schizophrenia: Perspectives From First-Degree Relatives. Schizophr Bull 2016; 42:1504-1516. [PMID: 27217271 PMCID: PMC5049529 DOI: 10.1093/schbul/sbw047] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
INTRODUCTION As endophenotypes bridge the gap between genetics and phenotypic disease expression, identifying reliable markers is important for fostering understanding of pathophysiology. The present aim was to conduct current meta-analyses of 3 key auditory event-related potential (ERP) components that have been held as potential endophenotypes for schizophrenia: P50, P300 amplitude and latency, and mismatch negativity (MMN), reflective of sensory gating, attention and classification speed, and perceptual discrimination ability, respectively. In order to assess endophenotype viability, these components were examined in unaffected relatives of patients with schizophrenia and healthy controls. METHODS Effect sizes (ES) were examined between relatives and controls for P50 suppression (10 studies, n = 360 relatives, 473 controls), P300 amplitude (20 studies, n = 868 relatives, 961 controls), P300 latency (17 studies, n = 674 relatives, 792 controls), and MMN (11 studies, n = 377 relatives, 552 controls). RESULTS Reliable differences in P50 suppression (ES = 0.86, P < .001), P300 amplitude (ES = -0.52, P < .001), and P300 latency (ES = 0.44, P < .05) were found between unaffected relatives and controls. A trend was found between relatives and controls for MMN (ES = 0.21, P = 0.06), and the use of extraneous channels was found to be a significant moderator (P = 0.01). When MMN was analyzed using frontocentral channel Fz, a significant difference was found (ES = 0.26, P < 0.01). DISCUSSION The results indicate that P50 suppression, P300 amplitude and P300 latency, and MMN may serve as viable endophenotypes for schizophrenia.
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Affiliation(s)
- Holly A. Earls
- Department of Psychology and Neuroscience, Center for Neuroscience, University of Colorado Boulder, Boulder, CO
| | - Tim Curran
- Department of Psychology and Neuroscience, Center for Neuroscience, University of Colorado Boulder, Boulder, CO
| | - Vijay Mittal
- Department of Psychology, Northwestern University, Evanston, IL
- Department of Psychiatry, Northwestern University, Chicago, IL
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12
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Broyd SJ, Michie PT, Bruggemann J, van Hell HH, Greenwood LM, Croft RJ, Todd J, Lenroot R, Solowij N. Schizotypy and auditory mismatch negativity in a non-clinical sample of young adults. Psychiatry Res Neuroimaging 2016; 254:83-91. [PMID: 27388803 DOI: 10.1016/j.pscychresns.2016.06.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 05/20/2016] [Accepted: 06/18/2016] [Indexed: 11/24/2022]
Abstract
Schizophrenia may be conceptualised using a dimensional approach to examine trait-like expression such as schizotypy within non-clinical populations to better understand pathophysiology. A candidate psychosis-risk marker, the auditory mismatch negativity (MMN) is thought to index the functionality of glutamatergic NMDA receptor mediated neurotransmission. Although the MMN is robustly reduced in patients with schizophrenia, the association between MMN and schizotypy in the general population is under-investigated. Thirty-five healthy participants completed the Schizotypal Personality Questionnaire (SPQ) and a multi-feature MMN paradigm (standards 82%, 50ms, 1000Hz, 80dB) with duration (100ms), frequency (1200Hz) and intensity (90dB) deviants (6% each). Spearman's correlations were used to explore the association between schizotypal personality traits and MMN amplitude. Few associations were identified between schizotypal traits and MMN. Higher Suspiciousness subscale scores tended to be correlated with larger frequency MMN amplitude. A median-split comparison of the sample on Suspiciousness scores showed larger MMN (irrespective of deviant condition) in the High compared to the Low Suspiciousness group. The trend-level association between MMN and Suspiciousness is in contrast to the robustly attenuated MMN amplitude observed in schizophrenia. Reductions in MMN may reflect a schizophrenia-disease state, whereas non-clinical schizotypy may not be subserved by similar neuropathology.
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Affiliation(s)
- Samantha J Broyd
- School of Psychology, Centre for Health Initiatives and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia.
| | - Patricia T Michie
- School of Psychology and Priority Research Centre for Translational Neuroscience and Mental Health University of Newcastle, Newcastle, NSW, Australia
| | - Jason Bruggemann
- School of Psychiatry, University of New South Wales and Neuroscience Research Australia, Sydney, Australia
| | - Hendrika H van Hell
- School of Psychology, Centre for Health Initiatives and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia
| | - Lisa-Marie Greenwood
- School of Psychology, Centre for Health Initiatives and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia
| | - Rodney J Croft
- School of Psychology, Centre for Health Initiatives and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia
| | - Juanita Todd
- School of Psychology and Priority Research Centre for Translational Neuroscience and Mental Health University of Newcastle, Newcastle, NSW, Australia
| | - Rhoshel Lenroot
- School of Psychiatry, University of New South Wales and Neuroscience Research Australia, Sydney, Australia
| | - Nadia Solowij
- School of Psychology, Centre for Health Initiatives and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia
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Ciullo V, Spalletta G, Caltagirone C, Jorge RE, Piras F. Explicit Time Deficit in Schizophrenia: Systematic Review and Meta-Analysis Indicate It Is Primary and Not Domain Specific. Schizophr Bull 2016; 42:505-18. [PMID: 26253596 PMCID: PMC4753592 DOI: 10.1093/schbul/sbv104] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Although timing deficits are a robust finding in schizophrenia (SZ), the notion of a genuine time perception disorder in SZ is still being debated because distortions in timing might depend on neuropsychological deficits that are characteristics of the illness. Here we used meta-analytic methods to summarize the evidence of timing deficits in SZ and moderator analyses to determine whether defective timing in SZ arises from nontemporal sources or from defective time perception. PubMed Services, PsycNET, and Scopus were searched through March 2015, and all references in articles were investigated to find other relevant studies. Studies were selected if they included subjects with a primary diagnosis of SZ compared to a healthy control (HC) group and if they reported behavioral measures of duration estimation (perceptual and motor explicit timing). Data from 24 studies published from 1956 to 2015, which comprised 747 SZ individuals and 808 HC, were included. Results indicate that SZ individuals are less accurate than HC in estimating time duration across a wide range of tasks. Subgroup analyses showed that the fundamental timing deficit in SZ is independent from the length of the to-be-timed duration (automatic and cognitively controlled timing) and from methods of stimuli estimation (perceptual and motor timing). Thus, time perception per se is disturbed in SZ (not just task-specific timing processes) and this perturbation is independent from more generalized cognitive impairments. Behavioral evidence of disturbed automatic timing should be more thoroughly investigated with the aim of defining it as a cognitive phenotype for more homogeneous diagnostic subgrouping.
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Affiliation(s)
- Valentina Ciullo
- Neuropsychiatry Laboratory, Department of Clinical and Behavioral Neurology, IRCCS Santa Lucia Foundation, Rome, Italy
| | - Gianfranco Spalletta
- Neuropsychiatry Laboratory, Department of Clinical and Behavioral Neurology, IRCCS Santa Lucia Foundation, Rome, Italy; Menninger Department of Psychiatry and Behavioral Sciences, Baylor College of Medicine, Houston, TX;
| | - Carlo Caltagirone
- Neuropsychiatry Laboratory, Department of Clinical and Behavioral Neurology, IRCCS Santa Lucia Foundation, Rome, Italy; Department of Systems Medicine, Tor Vergata University, Rome, Italy
| | - Ricardo E Jorge
- Menninger Department of Psychiatry and Behavioral Sciences, Baylor College of Medicine, Houston, TX
| | - Federica Piras
- Neuropsychiatry Laboratory, Department of Clinical and Behavioral Neurology, IRCCS Santa Lucia Foundation, Rome, Italy
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Terrien S, Gobin P, Iakimova G, Coutté A, Thuaire F, Baltazart V, Mazzola-Pomietto P, Besche-Richard C. Electrophysiological correlates of emotional meaning in context in relation to facets of schizotypal personality traits: A dimensional study. Psychiatry Clin Neurosci 2016; 70:141-50. [PMID: 26482112 DOI: 10.1111/pcn.12366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2015] [Revised: 09/28/2015] [Accepted: 10/15/2015] [Indexed: 11/29/2022]
Abstract
AIMS The aim of this study was to investigate the neurocognitive processes mediating the processing of emotional information during the integration of contextual and social information in a schizotypal population. METHODS One hundred and thirty-one healthy participants were evaluated using the Schizotypal Personality Questionnaire and event-related potentials were recorded during a linguistic task in which participants read sentence pairs describing short social situations to themselves. The first sentence implicitly conveyed the positive or negative emotional state of a character. The second sentence was emotionally congruent or incongruent with the first sentence. RESULTS Across our overall sample, our results revealed a greater N400 effect at right sites than left sites, whereas the late positive component effect was only observed at left sites. Concerning the correlation results, we observed a negative link between positive and global schizotypy and N400 modulation in response to congruent targets for positive context sentences. Results also showed a positive correlation between negative schizotypy and late positive component modulation in response to congruent targets for negative context sentences. CONCLUSIONS These results suggest that the different facets of the schizotypal personality traits influenced the integration of emotional context at the level of both early and later-mobilized neurocognitive processes.
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Affiliation(s)
- Sarah Terrien
- Cognition, Health, Socialisation Laboratory, University of Reims Champagne-Ardenne, Reims
| | - Pamela Gobin
- Cognition, Health, Socialisation Laboratory, University of Reims Champagne-Ardenne, Reims
| | - Galina Iakimova
- Anthropology, Cognitive and Social Psychology Laboratory, LAPCOS, University of Nice-Sophia Antipolis, Nice
| | - Alexandre Coutté
- Anthropology, Cognitive and Social Psychology Laboratory, LAPCOS, University of Nice-Sophia Antipolis, Nice
| | | | - Véronique Baltazart
- Cognition, Health, Socialisation Laboratory, University of Reims Champagne-Ardenne, Reims
| | | | - Chrystel Besche-Richard
- Cognition, Health, Socialisation Laboratory, University of Reims Champagne-Ardenne, Reims.,French Universitary Institute, Paris, France
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15
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Abstract
Endophenotypes are quantitative, heritable traits that may help to elucidate the pathophysiologic mechanisms underlying complex disease syndromes, such as schizophrenia. They can be assessed at numerous levels of analysis; here, we review electrophysiological endophenotypes that have shown promise in helping us understand schizophrenia from a more mechanistic point of view. For each endophenotype, we describe typical experimental procedures, reliability, heritability, and reported gene and neurobiological associations. We discuss recent findings regarding the genetic architecture of specific electrophysiological endophenotypes, as well as converging evidence from EEG studies implicating disrupted balance of glutamatergic signaling and GABAergic inhibition in the pathophysiology of schizophrenia. We conclude that refining the measurement of electrophysiological endophenotypes, expanding genetic association studies, and integrating data sets are important next steps for understanding the mechanisms that connect identified genetic risk loci for schizophrenia to the disease phenotype.
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Affiliation(s)
- Emily Owens
- Semel Institute for Neuroscience and Human Behavior, University of California Los Angeles, Los Angeles, CA
| | - Peter Bachman
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA
| | - David C Glahn
- Olin Neuropsychiatric Research Center, Institute of Living, Hartford, CT,Department of Psychiatry, Yale University School of Medicine, New Haven, CT
| | - Carrie E Bearden
- Semel Institute for Neuroscience and Human Behavior, University of California Los Angeles, Los Angeles, CA
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16
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García-Montes JM, Noguera C, Alvarez D, Ruiz M, Cimadevilla Redondo JM. High and low schizotypal female subjects do not differ in spatial memory abilities in a virtual reality task. Cogn Neuropsychiatry 2015; 19:427-38. [PMID: 24655143 DOI: 10.1080/13546805.2014.896786] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
INTRODUCTION Schizotypy is a psychological construct related to schizophrenia. The exact relationship between both entities is not clear. In recent years, schizophrenia has been associated with hippocampal abnormalities and spatial memory problems. The aim of this study was to determine possible links between high schizotypy (HS) and low schizotypy (LS) and spatial abilities, using virtual reality tasks. We hypothesised that the HS group would exhibit a lower performance in spatial memory tasks than the LS group. METHODS Two groups of female students were formed according to their score on the ESQUIZO-Q-A questionnaire. HS and LS subjects were tested on two different tasks: the Boxes Room task, a spatial memory task sensitive to hippocampal alterations and a spatial recognition task. RESULTS Data showed that both groups mastered both tasks. Groups differed in personality features but not in spatial performance. These results provide valuable information about the schizotypy-schizophrenia connections. CONCLUSION Schizotypal subjects are not impaired on spatial cognition and, accordingly, the schizotypy-schizophrenia relationship is not straightforward.
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Louise S, Gurvich C, Neill E, Tan EJ, Van Rheenen TE, Rossell S. Schizotypal Traits are Associated with Poorer Executive Functioning in Healthy Adults. Front Psychiatry 2015; 6:79. [PMID: 26082726 PMCID: PMC4450583 DOI: 10.3389/fpsyt.2015.00079] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 05/13/2015] [Indexed: 11/13/2022] Open
Abstract
Previous research has shown mild forms of the neurocognitive impairments seen in schizophrenia among healthy individuals exhibiting high schizotypal traits. This study aimed to explore associations between schizotypy and cognitive performance in an adult community sample. Ninety-five females and 79 males completed the Oxford-Liverpool Inventory of Feelings and Experiences (O-LIFE), which measures four separable aspects of schizotypy: cognitive disorganization, unusual experiences, introvertive anhedonia, and impulsive non-conformity. Subsequently, participants were administered a neurocognitive battery incorporating measures of executive skills including inhibition, cognitive flexibility, reasoning, and problem solving along with measures of attention and processing speed and both verbal and spatial working memory. In line with predictions, the current study found that higher scores on the subscales of unusual experiences, cognitive disorganization, and impulsive non-conformity related to worse performance on a measure of inhibition. Additionally, as introvertive anhedonia increased, both attention and processing speed and reasoning and problem-solving performance became more impaired. In conclusion, this study extends schizotypy literature by examining the subscales of the O-LIFE, and enables inferences to be drawn in relation to cognitive impairment in schizophrenia.
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Affiliation(s)
- Stephanie Louise
- Monash Alfred Psychiatry Research Centre (MAPrc), Alfred Hospital, Central Clinical School, Monash University , Melbourne, VIC , Australia ; Faculty of Health, Arts and Design, Brain and Psychological Sciences Research Centre, Swinburne University of Technology , Melbourne, VIC , Australia
| | - Caroline Gurvich
- Monash Alfred Psychiatry Research Centre (MAPrc), Alfred Hospital, Central Clinical School, Monash University , Melbourne, VIC , Australia
| | - Erica Neill
- Monash Alfred Psychiatry Research Centre (MAPrc), Alfred Hospital, Central Clinical School, Monash University , Melbourne, VIC , Australia ; Faculty of Health, Arts and Design, Brain and Psychological Sciences Research Centre, Swinburne University of Technology , Melbourne, VIC , Australia
| | - Eric J Tan
- Monash Alfred Psychiatry Research Centre (MAPrc), Alfred Hospital, Central Clinical School, Monash University , Melbourne, VIC , Australia ; Faculty of Health, Arts and Design, Brain and Psychological Sciences Research Centre, Swinburne University of Technology , Melbourne, VIC , Australia
| | - Tamsyn E Van Rheenen
- Monash Alfred Psychiatry Research Centre (MAPrc), Alfred Hospital, Central Clinical School, Monash University , Melbourne, VIC , Australia
| | - Susan Rossell
- Monash Alfred Psychiatry Research Centre (MAPrc), Alfred Hospital, Central Clinical School, Monash University , Melbourne, VIC , Australia ; Faculty of Health, Arts and Design, Brain and Psychological Sciences Research Centre, Swinburne University of Technology , Melbourne, VIC , Australia
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Neill E, Rossell SL, Kordzadze M. Investigating word associations in a schizotypy sample: contrasting implicit and explicit processing. Cogn Neuropsychiatry 2014; 19:134-48. [PMID: 23862769 DOI: 10.1080/13546805.2013.807727] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
INTRODUCTION Schizotypy is a useful schizophrenia analogue that controls for confounding factors such as medication and general intellectual decline. In the current study this analogue approach was used to examine implicit/explicit and direct/indirect semantic memory function. This is the first study to examine both implicit and explicit semantic access in the same schizotypy sample. METHODS Participants completed four semantic tasks: (1) implicit indirect priming, (2) implicit direct priming, (3) explicit object (indirect) task, and (4) explicit association (direct) task. The schizophrenia literature suggests that semantic impairments are associated with thought disorder. As such, participants were divided into low (n=18) and high (n=18) schizotypy groups based on their responses to a thought disorder subscale of the Oxford Liverpool Inventory of Feelings and Experiences (O-Life) scale. RESULTS In terms of implicit performance, the high schizotypy group demonstrated increased direct priming but nonsignificant indirect priming. The low schizotypy group demonstrated no significant difference in direct and indirect priming. Performance on the explicit tasks was equivalent between the two groups for direct stimuli. On the indirect explicit task, high schizotypy was associated with an increase in errors. CONCLUSIONS Increased direct priming in high schizotypy is equivalent to that seen in schizophrenia, which has been interpreted as increased spreading of activation. Abnormal performance using the indirect stimuli was found across implicit and explicit versions. The relevance of these findings to schizophrenia are discussed.
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Affiliation(s)
- Erica Neill
- a Cognitive Neuropsychology , MAPrc, Monash University, School of Psychology and Psychiatry , 1st Floor, Old Baker Building, The Alfred Hospital, Commercial Road, Melbourne , VIC 3004 , Australia
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Kiang M, Christensen BK, Zipursky RB. Event-related brain potential study of semantic priming in unaffected first-degree relatives of schizophrenia patients. Schizophr Res 2014; 153:78-86. [PMID: 24451397 DOI: 10.1016/j.schres.2014.01.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2013] [Revised: 12/25/2013] [Accepted: 01/02/2014] [Indexed: 10/25/2022]
Abstract
Schizophrenia is associated with abnormalities in using meaningful stimuli to activate or prime related concepts in semantic long-term memory. A neurophysiological index of this activation is the N400, an event-related brain potential (ERP) waveform elicited by meaningful stimuli, which is normally reduced (made less negative) by relatedness between the eliciting stimulus and preceding ones (N400 semantic priming). Schizophrenia patients exhibit N400 semantic priming deficits, suggesting impairment in using meaningful context to activate related concepts. To address whether this abnormality is a trait-like marker of liability to schizophrenia or, alternatively, a biomarker of the illness itself, we tested for its presence in schizophrenia patients' unaffected biological relatives. We recorded ERPs from 12 unaffected first-degree relatives of schizophrenia patients, 12 schizophrenia patients, and 12 normal control participants (NCPs) who viewed prime words each followed at 300- or 750-ms stimulus-onset asynchrony (SOA) by an unrelated or related target word, or a nonword, in a lexical-decision task. As expected, across SOAs, NCPs exhibited smaller (less negative) N400 amplitudes for related versus unrelated targets. The same pattern held in relatives, whose N400 amplitudes for related and unrelated targets did not differ from NCPs'. In contrast, consistent with previous results, schizophrenia patients exhibited larger N400 amplitudes than NCPs (and relatives) for related targets, such that patients' N400 amplitudes for related and unrelated targets did not differ. N400 amplitudes for unrelated targets did not differ between the three groups. Thus, N400 semantic priming deficits in a visual word-pair paradigm may be an illness biomarker for schizophrenia.
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Affiliation(s)
- Michael Kiang
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Ontario, Canada; St. Joseph's Healthcare, Hamilton, Ontario, Canada.
| | - Bruce K Christensen
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Ontario, Canada; St. Joseph's Healthcare, Hamilton, Ontario, Canada
| | - Robert B Zipursky
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Ontario, Canada; St. Joseph's Healthcare, Hamilton, Ontario, Canada
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Neill E. Methodological considerations in the recruitment and analysis of schizotypy samples. Front Psychiatry 2014; 5:156. [PMID: 25414674 PMCID: PMC4222126 DOI: 10.3389/fpsyt.2014.00156] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Accepted: 10/22/2014] [Indexed: 11/13/2022] Open
Affiliation(s)
- Erica Neill
- Monash Alfred Psychiatry Research Centre, Central Clinical School, Monash University , Melbourne, VIC , Australia ; Brain and Psychological Sciences Research Centre, Swinburne University of Technology , Melbourne, VIC , Australia
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Johannesen JK, O’Donnell BF, Shekhar A, McGrew JH, Hetrick WP. Diagnostic specificity of neurophysiological endophenotypes in schizophrenia and bipolar disorder. Schizophr Bull 2013; 39:1219-29. [PMID: 22927673 PMCID: PMC3796068 DOI: 10.1093/schbul/sbs093] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
BACKGROUND The utility of an endophenotype depends on its ability to reduce complex disorders into stable, genetically linked phenotypes. P50 and P300 event-related potential (ERP) measures are endophenotype candidates for schizophrenia; however, their abnormalities are broadly observed across neuropsychiatric disorders. This study examined the diagnostic efficiency of P50 and P300 in schizophrenia as compared with healthy and bipolar disorder samples. Supplemental ERP measures and a multivariate classification approach were evaluated as methods to improve specificity. METHODS Diagnostic classification was first modeled in schizophrenia (SZ = 50) and healthy normal (HN = 50) samples using hierarchical logistic regression with predictors blocked by 4 levels of analysis: (1) P50 suppression, P300 amplitude, and P300 latency; (2) N100 amplitude; (3) evoked spectral power; and (4) P50 and P300 hemispheric asymmetry. The optimal model was cross-validated in a holdout sample (SZ = 34, HN = 31) and tested against a bipolar (BP = 50) sample. RESULTS P50 and P300 endophenotypes classified SZ from HN with 71% accuracy (sensitivity = .70, specificity = .72) but did not differentiate SZ from BP above chance level. N100 and spectral power measures improved classification accuracy of SZ vs HN to 79% (sensitivity = .78, specificity = .80) and SZ vs BP to 72% (sensitivity = .74, specificity = .70). Cross validation analyses supported the stability of these models. CONCLUSIONS Although traditional P50 and P300 measures failed to differentiate schizophrenia from bipolar participants, N100 and evoked spectral power measures added unique variance to classification models and improved accuracy to nearly the same level achieved in comparison of schizophrenia to healthy individuals.
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Affiliation(s)
- Jason K. Johannesen
- Yale University School of Medicine, Department of PsychiatryNew Haven, CT;,VA Connecticut Healthcare SystemWest Haven, CT;,To whom correspondence should be addressed; VA Connecticut Health Care System, Psychology Service 116-B, 950 Campbell Ave, West Haven, CT 06516, US; tel: 203-932-5711 ext. 2224, fax: 203-937-4735; e-mail:
| | - Brian F. O’Donnell
- Indiana University, Department of Psychological and Brain SciencesBloomington, IN; ,Indiana University School of Medicine, Department of PsychiatryIndianapolis, IN;,Larue D. Carter Memorial HospitalIndianapolis, IN
| | - Anantha Shekhar
- Indiana University School of Medicine, Department of PsychiatryIndianapolis, IN;,Larue D. Carter Memorial HospitalIndianapolis, IN
| | - John H. McGrew
- Indiana University-Purdue University Indianapolis, Department of PsychologyIndianapolis, IN
| | - William P. Hetrick
- Indiana University, Department of Psychological and Brain SciencesBloomington, IN; ,Indiana University School of Medicine, Department of PsychiatryIndianapolis, IN;,Larue D. Carter Memorial HospitalIndianapolis, IN
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Abstract
Early phenomenological descriptions of schizophrenia have acknowledged the existence of milder schizophrenia spectrum disorders characterized by the presence of attenuated symptoms typically present in chronic schizophrenia. The investigation of the schizophrenia spectrum disorders offers an opportunity to elucidate the pathophysiological mechanisms giving rise to schizophrenia. Differences and similarities between subjects with schizotypal personality disorder (SPD), the prototypical schizophrenia personality disorder, and chronic schizophrenia have been investigated with genetic, neurochemical, imaging, and pharmacological techniques. Patients with SPD and the more severely ill patients with chronic schizophrenia share cognitive, social, and attentional deficits hypothesized to result from common neurodevelopmentally based cortical temporal and prefrontal pathology. However, these deficits are milder in SPD patients due to their capacity to recruit other related brain regions to compensate for dysfunctional areas. Individuals with SPD are also less vulnerable to psychosis due to the presence of protective factors mitigating subcortical DA hyperactivity. Given the documented close relationship to other schizophrenic disorders, SPD will be included in the psychosis section of DSM-5 as a schizophrenia spectrum disorder as well as in the personality disorder section.
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de Loye C, Beaucousin V, Bohec AL, Blanchet A, Kostova M. An event-related potential study of predictive and integrative semantic context processing in subjects with schizotypal traits. Psychophysiology 2013; 50:1109-19. [DOI: 10.1111/psyp.12124] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Claire de Loye
- Laboratoire de Psychopathologie et Neuropsychologie (EA 2027); Université Paris 8; Saint-Denis France
| | - Virginie Beaucousin
- Laboratoire de Psychopathologie et Neuropsychologie (EA 2027); Université Paris 8; Saint-Denis France
| | - Anne-Lise Bohec
- Laboratoire de Psychopathologie et Neuropsychologie (EA 2027); Université Paris 8; Saint-Denis France
| | - Alain Blanchet
- Laboratoire de Psychopathologie et Neuropsychologie (EA 2027); Université Paris 8; Saint-Denis France
| | - Milena Kostova
- Laboratoire de Psychopathologie et Neuropsychologie (EA 2027); Université Paris 8; Saint-Denis France
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Électrophysiologie et vulnérabilité schizophrénique : la composante N400 comme endophénotype candidat ? Neurophysiol Clin 2013; 43:81-94. [DOI: 10.1016/j.neucli.2013.01.119] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Revised: 01/22/2013] [Accepted: 01/28/2013] [Indexed: 11/20/2022] Open
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Abstract
PURPOSE OF REVIEW The purpose of this article is to review major findings in event related potential (ERP) research in schizophrenia patients, specifically focusing on the N400 component. RECENT FINDINGS Patients with chronic schizophrenia have difficulty using 'context' (understanding the meaning of the word relative to the sentence) in sentence processing studies and often show differences from control populations in language experiments using word priming. Both of these observations are associated with an abnormal N400 ERP component when compared with nonpsychotic individuals. Many studies of language function rely on priming paradigms that use pairs of words such that the first word in a pair is a 'prime' and a second word in a pair is a 'target', separated from the prime by a period of time known as the Stimulus Onset Asynchrony (SOA). If the SOA is short (i.e., below 400 ms) then it is believed that a priming study examines primarily processes of initial activation within semantic networks; if it is long (i.e., more than 400 ms) then it is believed that a priming study examines primarily processes of context use, generating predictions and matching these predictions against upcoming semantic information. Priming paradigms that use long SOAs are consistently associated with a more negative N400 (hence lack of priming) in schizophrenia, whereas priming paradigms using a short SOA produce either a normal N400 priming response or hyperpriming as shown by a reduced N400 and related to a hypothesized too rapid automatic spread of activation within the semantic memory pathway. Apparent differences among reported study results are likely due to paradigm differences that tap into different aspects of language processing. Although the presence of both hyperactivation within semantic networks and difficulties with the use of context is well known in schizophrenia, it is unclear whether these abnormalities are also present prior to illness onset in people who are at risk for development of schizophrenia or even present at the onset of illness. SUMMARY In order to clarify the findings reviewed here, future studies will be needed that focus on examining the N400 response in young people at high risk for developing the illness using multiple paradigms that probe different aspects of language function.
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Micoulaud Franchi JA, Vion Dury J, Cermolacce M. [Neurophysiological endophenotypes and schizophrenic disorder: emergence and evolution of a clinical concept]. Encephale 2013; 38 Suppl 3:S103-9. [PMID: 23279983 DOI: 10.1016/s0013-7006(12)70087-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
It is proposed an historical approach to concepts leading to the development of operational paradigms for measuring objectives neurophysiological endophenotypes. It is hypothesized that psychiatric interest for paradigms measuring Event-Related Potential (ERP) come from Bleuler (1911) and McGhie and Chapman (1961) phenomenological and clinical descriptions. They noted, first that patients with schizophrenia generally feel as if they are being flooded by an overwhelming mass of sensory input combined with a heightened sensory perception, second that they were distractible to irrelevant sensory stimuli. These subjective abnormalities may be related, first to inability to filter incongruent information measured in a double click paradigm by a deficit in P50 amplitude gating, and second to an inability to select a stimulus of interest measured in the oddball paradigm by a deficit in P300 amplitude. The analysis of these P50 and P300 ERP in cohorts of patients with schizophrenia found most of Gottesman endophenotype criteria. P50 and P300 ERP are therefore relevant neurophysiological endophenotypes. However, from a clinical point of view, these endophenotypes lack specificity. The hypothesis of this article leads us to formulate ways of research. It is shown the value of combining objective neurophysiological measures with subjective measures using self-administered questionnaires ("offline") or psychophysiological tests ("online") to develop rigorous neurophysiological experimental paradigms especially as clinical observations of their origins are not forgotten.
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Affiliation(s)
- J-A Micoulaud Franchi
- Unité de Neurophysiologie, Psychophysiologie et Neurophénoménologie (UNPN), Solaris, Pôle de Psychiatrie Universitaire, Hôpital Sainte-Marguerite, 270 boulevard Sainte-Marguerite, Marseille, France.
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Pfeifer S, Schiller NO, van Os J, Riedel WJ, Vlamings P, Simons C, Krabbendam L. Electrophysiological correlates of automatic spreading of activation in patients with psychotic disorder and first-degree relatives. Int J Psychophysiol 2012; 84:102-12. [DOI: 10.1016/j.ijpsycho.2012.01.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Revised: 01/06/2012] [Accepted: 01/13/2012] [Indexed: 10/14/2022]
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Auditory steady state response in the schizophrenia, first-degree relatives, and schizotypal personality disorder. Schizophr Res 2012; 136:143-9. [PMID: 22285558 PMCID: PMC3298621 DOI: 10.1016/j.schres.2012.01.003] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2011] [Revised: 12/29/2011] [Accepted: 01/04/2012] [Indexed: 11/24/2022]
Abstract
The power and phase synchronization of the auditory steady state response (ASSR) at 40 Hz stimulation is usually reduced in schizophrenia (SZ). The sensitivity of the 40 Hz ASSR to schizophrenia spectrum phenotypes, such as schizotypal personality disorder (SPD), or to familial risk has been less well characterized. We compared the ASSR of patients with SZ, persons with schizotypal personality disorder, first degree relatives of patients with SZ, and healthy control participants. ASSRs were obtained to 20, 30, 40 and 50 Hz click trains, and assessed using measures of power (mean trial power or MTP) and phase consistency (phase locking factor or PLF). The MTP to 40 Hz stimulation was reduced in relatives, and there was a trend for MTP reduction in SZ. The 40 Hz ASSR was not reduced in SPD participants. PLF did not differ among groups. These data suggest the 40 Hz ASSR is sensitive to familial risk factors associated with schizophrenia.
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Simons CJ, Sambeth A, Krabbendam L, Pfeifer S, van Os J, Riedel WJ. Auditory P300 and N100 components as intermediate phenotypes for psychotic disorder: Familial liability and reliability. Clin Neurophysiol 2011; 122:1984-90. [DOI: 10.1016/j.clinph.2011.02.033] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2010] [Revised: 02/21/2011] [Accepted: 02/28/2011] [Indexed: 11/26/2022]
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Şevik AE, Anıl Yağcıoğlu AE, Yağcıoğlu S, Karahan S, Gürses N, Yıldız M. Neuropsychological performance and auditory event related potentials in schizophrenia patients and their siblings: a family study. Schizophr Res 2011; 130:195-202. [PMID: 21592733 DOI: 10.1016/j.schres.2011.04.018] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2011] [Revised: 04/10/2011] [Accepted: 04/17/2011] [Indexed: 11/29/2022]
Abstract
BACKGROUND Various neuropsychological domains, and P300 auditory event-related potentials (ERP) and mismatch negativity (MMN) exhibit abnormalities in schizophrenia patients and their first-degree relatives. The aims of this study were to compare cognitive and P300/MMN measurements in schizophrenia patients, their siblings, and controls, and to identify the degree of familial influence on each measure. METHODS Thirty patients diagnosed with schizophrenia according to DSM-IV, 20 unaffected siblings and 25 healthy controls were able to complete all neuropsyhological and neurophysiological assessments. All participants were administered SCID-I and the patients were also evaluated regarding symptom severity and functioning. Neuropsychological battery testing results and P300/MMN measurements were obtained for all the participants. RESULTS Both schizophrenia patients and their siblings had lower working memory, as measured by the Auditory Consonant Trigram Test (ACT), and lower MMN amplitude scores than the controls. In addition, the patients had lower attention, verbal memory, executive function, visuomotor speed, and figural memory scores than both the siblings and controls, and lower verbal fluency scores than controls. MMN and P300 amplitudes were lower and P300 latency longer in the schizophrenia patients, as compared to controls. P300 latency was also longer in the schizophrenia patients as compared to siblings and, MMN amplitudes were significantly lower in the siblings compared to controls. Working memory performance measured by ACT significantly predicted inclusion in both the patient and sibling groups and showed significant familial influence. MMN amplitude significantly predicted inclusion only to the patient group and did not show significant familial influence. CONCLUSION The schizophrenia patients exhibited impairment in various cognitive domains and P300/MMN measurements, versus impairment only in working memory and MMN amplitude in their siblings. Working memory seems to have a relatively strong familial influence among all the neuropsychological and neurophysiological parameters evaluated.
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Affiliation(s)
- Ali Emre Şevik
- Başkent University, Faculty of Medicine, Department of Psychiatry, Ankara, Turkey
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Increased psychophysiological parameters of attention in non-psychotic individuals with auditory verbal hallucinations. Schizophr Res 2010; 121:153-9. [PMID: 20494553 DOI: 10.1016/j.schres.2010.04.017] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2009] [Revised: 04/12/2010] [Accepted: 04/26/2010] [Indexed: 11/23/2022]
Abstract
OBJECTIVE Schizophrenia is associated with aberrant event-related potentials (ERPs) such as reductions in P300, processing negativity and mismatch negativity amplitudes. These deficits may be related to the propensity of schizophrenia patients to experience auditory verbal hallucinations (AVH). However, AVH are part of extensive and variable symptomatology in schizophrenia. For this reason non-psychotic individuals with AVH as an isolated symptom provide an excellent opportunity to investigate this relationship. METHODS P300 waveforms, processing negativity and mismatch negativity were examined with an auditory oddball paradigm in 18 non-psychotic individuals with AVH and 18 controls. RESULTS P300 amplitude was increased in the AVH group as compared to controls, reflecting superior effortful attention. A trend in the same direction was found for processing negativity. No significant differences were found for mismatch negativity. CONCLUSION Contrary to our expectations, non-psychotic individuals with AVH show increased rather than decreased psychophysiological measures of effortful attention compared to healthy controls, refuting a pivotal role of decreased effortful attention in the pathophysiology of AVH.
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Abstract
Facial emotion recognition deficits have been widely investigated in individuals with schizophrenia; however, it remains unclear whether these deficits reflect a trait-like vulnerability to schizophrenia pathology present in individuals at risk for the disorder. Although some studies have investigated emotion recognition in this population, findings have been mixed. The current study uses a well-validated emotion recognition task, a relatively large sample, and examines the relationship between emotion recognition, symptoms, and overall life quality. Eighty-nine individuals with psychometrically defined schizotypy and 27 controls completed the Schizotypal Personality Questionnaire, Penn Emotion Recognition Test, and a brief version of Lehman's Quality of Life Interview. In addition to labeling facial emotions, participants rated the valence of faces using a Likert rating scale. Individuals with schizotypy were significantly less accurate than controls when labeling emotional faces, particularly neutral faces. Within the schizotypy sample, both disorganization symptoms and lower quality of life were associated with a bias toward perceiving facial expressions as more negative. Our results support previous research suggesting that poor emotion recognition is associated with vulnerability to psychosis. Although emotion recognition appears unrelated to symptoms, it probably operates by means of different processes in those with particular types of symptoms.
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Rapp AM, Mutschler DE, Wild B, Erb M, Lengsfeld I, Saur R, Grodd W. Neural correlates of irony comprehension: the role of schizotypal personality traits. BRAIN AND LANGUAGE 2010; 113:1-12. [PMID: 20071019 DOI: 10.1016/j.bandl.2009.11.007] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2009] [Revised: 10/06/2009] [Accepted: 11/21/2009] [Indexed: 05/28/2023]
Abstract
To detect that a conversational turn is intended to be ironic is a difficult challenge in everyday language comprehension. Most authors suggested a theory of mind deficit is crucial for irony comprehension deficits in psychiatric disorders like schizophrenia; however, the underlying pathophysiology and neurobiology are unknown and recent research highlights the possible role of language comprehension abnormalities. Fifteen female right-handed subjects completed personality testing as well as functional magnetic resonance imaging (fMRI) and neuropsychology. Subjects were recruited from the general population. No subject had a lifetime history of relevant psychiatric disorder; however, subjects differed in their score on the German version of the schizotypal personality questionnaire (SPQ). During fMRI scans, the subjects silently read 44 short text vignettes that ended in either an ironic or a literal statement. Imaging was performed using a 3 T Siemens scanner. The influence of schizotypy on brain activation was investigated by using an SPM5 regression analysis with the SPQ total score and the SPQ cognitive-perceptual score as regressors. Reading ironic in contrast to literal sentences activated a bilateral network including left medial prefrontal and left inferior parietal gyri. During reading of ironic sentences, brain activation in the middle temporal gyrus of both hemispheres showed a significant negative association with the SPQ total score and the SPQ cognitive-perceptual score. Significant positive correlation with the SPQ total score was present in the left inferior frontal gyrus. We conclude schizotypal personality traits are associated with a dysfunctional lateral temporal language rather than a theory of mind network.
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Affiliation(s)
- A M Rapp
- Department of Psychiatry, University of Tuebingen, Osianderstrasse 26, Tuebingen, Germany.
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Pallanti S, Castellini G, Chamberlain SR, Quercioli L, Zaccara G, Fineberg NA. Cognitive event-related potentials differentiate schizophrenia with obsessive-compulsive disorder (schizo-OCD) from OCD and schizophrenia without OC symptoms. Psychiatry Res 2009; 170:52-60. [PMID: 19800695 DOI: 10.1016/j.psychres.2008.11.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2007] [Revised: 06/15/2008] [Accepted: 11/02/2008] [Indexed: 10/20/2022]
Abstract
Clinical and neurobiological evidence suggests that concurrent presentation of schizophrenia and obsessive-compulsive (schizo-OCD) symptoms represents a distinct clinical entity. Given that obsessive-compulsive disorder (OCD) and schizophrenia have been modeled as having different neurofunctional profiles, the overlap between them represents a heuristic challenge for cognitive and endophenotype research. Event-related potentials (ERPs) may be used to probe neurophysiological correlates of the cognitive, emotional and behavioral disturbances found in neuropsychiatric entities such as schizo-OCD. Here we measure ERPs during a discriminative response task (DRT) in patients presenting with the DSM-IV criteria for both schizophrenia and OCD. We also performed these measurements in patients with OCD without psychotic features, as well as in patients with schizophrenia without OC symptoms. Schizo-OCD patients showed a distinct ERP pattern, with abnormally increased target activation (akin to OCD patients, but unlike the pattern observed in schizophrenic patients) and reduced P300 amplitudes (akin to schizophrenic patients, but unlike OCD patients). Similar to the control subjects, schizo-OCD patients showed larger amplitudes in the non-target condition than in the target condition. These results suggest that schizo-OCD may not only be a distinct clinical entity from pure OCD and schizophrenia, but it may also be characterized by a distinguishable neurophysiologic pattern. Neurobiological underpinnings deserve further considerations and might drive to a definition of a distinctive endophenotype for schizo-OCD in the de-construction of the schizophrenia endophenotype.
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Affiliation(s)
- Stefano Pallanti
- Institute for Neurosciences, Viale Ugo Bassi, Firenze 50137, Italy.
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An event-related brain potential study of schizotypal personality and associative semantic processing. Int J Psychophysiol 2009; 75:119-26. [PMID: 19818815 DOI: 10.1016/j.ijpsycho.2009.10.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2007] [Revised: 04/25/2008] [Accepted: 04/30/2008] [Indexed: 11/24/2022]
Abstract
To examine whether schizotypal personality is associated with the degree to which concepts activate each other in semantic memory, event-related brain potentials (ERPs) were recorded during a delayed lexical decision task from healthy volunteers rated for schizotypy. Each target word was directly, indirectly, or not at all related to a prime word preceding it at a 300- or 750-ms stimulus-onset asynchrony (SOA). Overall, N400 amplitudes were largest for unrelated targets, smallest for directly related targets, and intermediate for indirectly related targets. Higher total Schizotypal Personality Questionnaire (SPQ) scores correlated with smaller N400 indirect priming effects (i.e., smaller N400 amplitude differences between unrelated and indirectly related targets) at both SOAs. In addition, schizotypal subscale scores were differentially associated with N400 effects. Higher SPQ Cognitive-Perceptual scores correlated with smaller N400 direct priming effects (smaller N400 amplitude differences between unrelated and directly related targets) at both SOAs, and with smaller N400 indirect priming effects at the shorter SOA. These correlations are consistent with the hypothesis that decreased use of meaningful context to activate related concepts in general, and/or to inhibit unrelated concepts, may play some role in the development of unusual beliefs.
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Leonards U, Mohr C. Schizotypal personality traits influence idiosyncratic initiation of saccadic face exploration. Vision Res 2009; 49:2404-13. [PMID: 19643123 DOI: 10.1016/j.visres.2009.07.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2009] [Revised: 07/14/2009] [Accepted: 07/24/2009] [Indexed: 10/20/2022]
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Carroll CA, O’Donnell BF, Shekhar A, Hetrick WP. Timing dysfunctions in schizophrenia span from millisecond to several-second durations. Brain Cogn 2009; 70:181-90. [DOI: 10.1016/j.bandc.2009.02.001] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2008] [Revised: 01/26/2009] [Accepted: 02/01/2009] [Indexed: 11/17/2022]
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N400 deficits from semantic matching of pictures in probands and first-degree relatives from multiplex schizophrenia families. Brain Cogn 2009; 70:221-30. [PMID: 19307049 DOI: 10.1016/j.bandc.2009.02.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2008] [Revised: 02/01/2009] [Accepted: 02/03/2009] [Indexed: 11/23/2022]
Abstract
Endophenotypes is one emerging strategy in schizophrenia research that is being used to identify the functional importance of genetically transmitted, brain-based deficits present in this disease. Currently, event-related potentials (ERPs) are timely used in this search. Several ERPs, including N400, present deficits in relation to schizophrenia. In order to assess the genetic liability of N400 as a possible endophenotype, a picture semantic matching task (congruent and incongruent pairs of pictures) was performed by 21 unaffected first-degree relatives of patients with schizophrenia, 21 DSM-IV diagnosed schizophrenia probands, and 21 control subjects, matched by age, gender and educational level. Probands and relatives were selected form Multiplex schizophrenia families. Significantly reduced N400 amplitude for congruent categories in N400 was found in probands and relatives in relation to controls. The latency onset and the maximum peak latency of N400 were delayed in both, relatives and probands groups compared to control. The voltage maps of incongruous-minus-congruous difference indicate a more reduced right restricted negativity in probands and relatives, when compared to a widely extended bilateral negativity in controls. No general differences were found between patients and relatives. These results demonstrate an electrophysiological deficit in semantic match processing in clinically unaffected first-degree relatives of patients with schizophrenia, suggesting a possible use of this marker as endophenotype.
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de Wilde OM, Bour LJ, Dingemans PM, Koelman JHTM, Boerée T, Linszen DH. P300 deficits are present in young first-episode patients with schizophrenia and not in their healthy young siblings. Clin Neurophysiol 2008; 119:2721-6. [PMID: 18986832 DOI: 10.1016/j.clinph.2008.08.024] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2008] [Revised: 05/27/2008] [Accepted: 08/21/2008] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To evaluated P300 (P3b) abnormalities in young first episode patients with schizophrenia and their healthy young siblings. METHODS An auditory oddball paradigm was used to assess P300 in 53 patients, 27 unaffected siblings and 28 healthy controls. Amplitude and latency of the three midline sites (Fz, Cz, and Pz) were compared between patients, siblings, and controls by a mixed-effects regression model. RESULTS P300 amplitude was significantly reduced in patients with schizophrenia but not in healthy siblings, when compared to healthy controls. P300 latency did not significantly differ between the three groups. CONCLUSIONS P300 amplitude but not latency was found to be affected in young patients with recent onset schizophrenia. However, P300 amplitude and latency were found not to be affected in healthy unaffected young siblings and, therefore, did not qualify as an endophenotype for schizophrenia. SIGNIFICANCE The failure to find the P300 (P3b) abnormality in healthy siblings of patients with schizophrenia is an important finding and should be added to P300 literature.
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Affiliation(s)
- O M de Wilde
- Department of Psychiatry, Academic Medical Centre, University of Amsterdam, Meibergdreef 5, 1105 AZ, Amsterdam, The Netherlands
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Auditory processing abnormalities in schizotypal personality disorder: an fMRI experiment using tones of deviant pitch and duration. Schizophr Res 2008; 103:26-39. [PMID: 18555666 PMCID: PMC3188851 DOI: 10.1016/j.schres.2008.04.041] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2008] [Revised: 04/18/2008] [Accepted: 04/24/2008] [Indexed: 11/22/2022]
Abstract
BACKGROUND One of the cardinal features of schizotypal personality disorder (SPD) is language abnormalities. The focus of this study was to determine whether or not there are also processing abnormalities of pure tones differing in pitch and duration in SPD. METHODS Thirteen neuroleptic-naïve male subjects met full criteria for SPD and were group-matched on age and parental socio-economic status to 13 comparison subjects. Verbal learning was measured with the California Verbal Learning Test. Heschl's gyrus volumes were measured using structural MRI. Whole-brain fMRI activation patterns in an auditory task of listening to tones including pitch and duration deviants were compared between SPD and control subjects. In a second and separate ROI analysis we found that peak activation in superior temporal gyrus (STG), Brodmann Areas 41 and 42, was correlated with verbal learning and clinical measures derived from the SCID-II interview. RESULTS In the region of the STG, SPD subjects demonstrated more activation to pitch deviants bilaterally (p<0.001); and to duration deviants in the left hemisphere (p=0.005) (two-sample t). SPD subjects also showed more bilateral parietal cortex activation to duration deviants. In no region did comparison subjects activate more than SPD subjects in either experiment. Exploratory correlations for SPD subjects suggest a relationship between peak activation on the right for deviant tones in the pitch experiment with odd speech and impaired verbal learning. There was no difference between groups on Heschl's gyrus volume. CONCLUSIONS These data suggest that SPD subjects have inefficient or hyper-responsive processing of pure tones both in terms of pitch and duration deviance that is not attributable to smaller Heschl's gyrus volumes. Finally, these auditory processing abnormalities may have significance for the odd speech heard in some SPD subjects and downstream language and verbal learning deficits.
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Carroll CA, Boggs J, O’Donnell BF, Shekhar A, Hetrick WP. Temporal processing dysfunction in schizophrenia. Brain Cogn 2008; 67:150-61. [PMID: 18262701 PMCID: PMC2512257 DOI: 10.1016/j.bandc.2007.12.005] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2007] [Revised: 12/19/2007] [Accepted: 12/23/2007] [Indexed: 11/21/2022]
Abstract
Schizophrenia may be associated with a fundamental disturbance in the temporal coordination of information processing in the brain, leading to classic symptoms of schizophrenia such as thought disorder and disorganized and contextually inappropriate behavior. Despite the growing interest and centrality of time-dependent conceptualizations of the pathophysiology of schizophrenia, there remains a paucity of research directly examining overt timing performance in the disorder. Accordingly, the present study investigated timing in schizophrenia using a well-established task of time perception. Twenty-three individuals with schizophrenia and 22 non-psychiatric control participants completed a temporal bisection task, which required participants to make temporal judgments about auditory and visually presented durations ranging from 300 to 600 ms. Both schizophrenia and control groups displayed greater visual compared to auditory timing variability, with no difference between groups in the visual modality. However, individuals with schizophrenia exhibited less temporal precision than controls in the perception of auditory durations. These findings correlated with parameter estimates obtained from a quantitative model of time estimation, and provide evidence of a fundamental deficit in temporal auditory precision in schizophrenia.
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Affiliation(s)
- Christine A. Carroll
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN
| | - Jennifer Boggs
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Brian F. O’Donnell
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, USA
- Larue D. Carter Memorial Hospital, Indianapolis, IN, USA
| | - Anantha Shekhar
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, USA
- Larue D. Carter Memorial Hospital, Indianapolis, IN, USA
| | - William P. Hetrick
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, USA
- Larue D. Carter Memorial Hospital, Indianapolis, IN, USA
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Kiang M, Kutas M, Light GA, Braff DL. Electrophysiological insights into conceptual disorganization in schizophrenia. Schizophr Res 2007; 92:225-36. [PMID: 17383161 PMCID: PMC3974604 DOI: 10.1016/j.schres.2007.02.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2006] [Revised: 01/31/2007] [Accepted: 02/02/2007] [Indexed: 11/21/2022]
Abstract
Disorganized speech, or thought disorder, in schizophrenia may reflect abnormal processing of meaningful concepts. To examine whether schizophrenia involves abnormalities in how a meaningful context influences processing of concepts strongly, weakly, or not related to it, we used the N400, an event-related brain potential (ERP) index of semantic relatedness. ERPs were recorded from schizophrenia patients (n=18) and normal controls (n=18) while they viewed category definitions (e.g., a type of fruit), each followed by a target word that was either a high-typicality category exemplar (apple), low-typicality exemplar (cherry), or non-exemplar (clamp). Participants' task was to indicate via button-press whether or not the target belonged to the category. In both patients and controls, N400 amplitude was largest (most negative) for non-exemplars, intermediate for low-typicality exemplars, and smallest (least negative) for high-typicality exemplars. Compared to controls, patients showed a trend toward reduced N400 amplitude differences between non-exemplars and low-typicality exemplars. Most importantly, within patients, reduced N400 amplitude differences between high- and low-typicality exemplars were correlated with psychotic symptoms. This association of an N400 index of semantic processing with psychotic symptoms suggests that psychosis in schizophrenia may be associated with greater similarity in how concepts strongly and weakly meaningfully related to their context are processed.
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Affiliation(s)
- Michael Kiang
- Department of Cognitive Science, University of California-San Diego, 9500 Gilman Dr., Mail Code 0515, La Jolla, CA 92093-0515, USA.
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Turetsky BI, Calkins ME, Light GA, Olincy A, Radant AD, Swerdlow NR. Neurophysiological endophenotypes of schizophrenia: the viability of selected candidate measures. Schizophr Bull 2007; 33:69-94. [PMID: 17135482 PMCID: PMC2632291 DOI: 10.1093/schbul/sbl060] [Citation(s) in RCA: 415] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
In an effort to reveal susceptibility genes, schizophrenia research has turned to the endophenotype strategy. Endophenotypes are characteristics that reflect the actions of genes predisposing an individual to a disorder, even in the absence of diagnosable pathology. Individual endophenotypes are presumably determined by fewer genes than the more complex phenotype of schizophrenia and would, therefore, reduce the complexity of genetic analyses. Unfortunately, despite there being rational criteria to define a viable endophenotype, the term is sometimes applied indiscriminately to characteristics that are deviant in affected individuals. Schizophrenia patients exhibit deficits in several neurophysiological measures of information processing that have been proposed as candidate endophenotypes. Successful processing of sensory inputs requires the ability to inhibit intrinsic responses to redundant stimuli and, reciprocally, to facilitate responses to less frequent salient stimuli. There is evidence to suggest that both these processes are "impaired" in schizophrenia. Measures of inhibitory failure include prepulse inhibition of the startle reflex, P50 auditory evoked potential suppression, and antisaccade eye movements. Measures of impaired deviance detection include mismatch negativity and the P300 event-related potential. The purpose of this review is to systematically evaluate the endophenotype candidacy of these key neurophysiological abilities. For each candidate, we describe typical experimental procedures, the current understanding of the underlying neurobiology, the nature of the abnormality in schizophrenia, the reliability, stability and heritability of the measure, and any reported gene associations. We conclude with a discussion of the few studies thus far that have employed a multivariate approach with these candidates.
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Affiliation(s)
- Bruce I Turetsky
- Department of Psychiatry, 10th floor, Gates Building, University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104, USA.
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Kiang M, Kutas M. Abnormal typicality of responses on a category fluency task in schizotypy. Psychiatry Res 2006; 145:119-26. [PMID: 17070931 DOI: 10.1016/j.psychres.2005.12.010] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2005] [Revised: 11/14/2005] [Accepted: 12/28/2005] [Indexed: 10/24/2022]
Abstract
Existing hypotheses about semantic processing in schizophrenia and schizotypy suggest that both conditions are associated with a less than normal difference in the degree to which some concept activates the mental representation of other concepts that are strongly versus weakly related to it in meaning. To seek further evidence for this, we examined response typicality on the Category Fluency Test (CFT) as a function of schizotypy. Individuals from a non-clinical population verbally generated as many exemplars as they could in 1 min for each of four categories (fruits, four-footed animals, articles of clothing, vehicles). Participants subsequently completed the Schizotypal Personality Questionnaire (SPQ). SPQ score was not significantly correlated with the total number of responses generated for any of the categories. Individuals with higher (as opposed to lower) SPQ scores, however, generated more atypical members of the fruit category both in their initial responses and overall (as indexed by the average ratio of each response's ordinal position to its position in population typicality norms). These results support the hypothesis that semantic memory organization in non-clinical individuals with higher schizotypy is functionally altered.
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Affiliation(s)
- Michael Kiang
- Department of Cognitive Science, University of California, San Diego, Mail Code 0515, 9500 Gilman Dr., La Jolla, CA 92093-0515, USA.
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45
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Gassab L, Mechri A, Dogui M, Gaha L, d'Amato T, Dalery J, Saoud M. Abnormalities of auditory event-related potentials in students with high scores on the Schizotypal Personality Questionnaire. Psychiatry Res 2006; 144:117-22. [PMID: 17007936 DOI: 10.1016/j.psychres.2004.09.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2003] [Revised: 08/28/2004] [Accepted: 09/08/2004] [Indexed: 11/30/2022]
Abstract
Some auditory event-related potential (ERP) abnormalities characterize both patients with schizophrenia and subjects with schizotypal personality disorder. It was therefore hypothesized that subjects from the community with schizotypal traits might also present ERP abnormalities. In this study, we compared auditory ERP latencies and amplitudes in 13 subjects with high (H-SPQ) and 12 subjects with low (L-SPQ) scores on the Schizotypal Personality Questionnaire (SPQ), selected from 198 Tunisian students. Auditory ERPs were recorded at Fz, Cz, and Pz, with a standard oddball paradigm. Smaller P300 amplitudes and delayed P300 latencies were found in H-SPQ compared with L-SPQ participants. Confirming previous reports, our results suggest that reduced P300 amplitudes and delayed P300 latencies may be considered as vulnerability markers of the schizophrenia spectrum in nonclinical subjects from the community.
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Affiliation(s)
- Leila Gassab
- Unité de Recherche en Psychiatrie, Faculté de Médecine de Monastir, 5019 Monastir, Tunisia
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Umbricht DSG, Bates JA, Lieberman JA, Kane JM, Javitt DC. Electrophysiological indices of automatic and controlled auditory information processing in first-episode, recent-onset and chronic schizophrenia. Biol Psychiatry 2006; 59:762-72. [PMID: 16497277 DOI: 10.1016/j.biopsych.2005.08.030] [Citation(s) in RCA: 147] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2005] [Revised: 08/10/2005] [Accepted: 08/25/2005] [Indexed: 10/25/2022]
Abstract
BACKGROUND Deficits in amplitudes of auditory event-related potentials (ERP) indexing preattentive, automatic (mismatch negativity, MMN) and controlled, attention-dependent (N2, P3) auditory information processing have been well described in chronic schizophrenia. Normal MMN, but deficient N2 and P3 have been reported in first-episode patients. No study has investigated these ERPs concurrently in first-episode patients; thus, reported differences in MMN, N2 and P3 generation may reflect differences in patient samples rather than genuine differences in abnormal generation of these ERPs. METHODS We recorded MMN, N2 and P3 in 26 first-episode patients, 25 recent-onset patients within 1.5 to 5 years after first admission, 25 chronic patients and 39 healthy controls. RESULTS Recent-onset and chronic, but not first-episode patients showed reduced MMN. However, among first-episode patients those with low premorbid educational achievement demonstrated significantly reduced MMN. All patient groups showed pronounced N2 deficits and, to a variable extent, abnormalities in P3 generation. CONCLUSIONS Abnormalities in N2 and P3 generation appear to reflect premorbid neuropathology, whereas MMN deficits may index both ongoing disease processes associated with illness progression as well as premorbid neurocognitive impairment. ERPs may provide tools to assess static and progressive neuropathology in schizophrenia. These findings need confirmation in longitudinal studies.
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Affiliation(s)
- Daniel S G Umbricht
- Exploratory Clinical Development, Translational Medicine, Novartis Pharma AG, Basel, Switzerland.
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Diwadkar VA, Montrose DM, Dworakowski D, Sweeney JA, Keshavan MS. Genetically predisposed offspring with schizotypal features: an ultra high-risk group for schizophrenia? Prog Neuropsychopharmacol Biol Psychiatry 2006; 30:230-8. [PMID: 16318899 DOI: 10.1016/j.pnpbp.2005.10.019] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2005] [Indexed: 10/25/2022]
Abstract
Biomarkers proposed in the schizophrenia diathesis have included neurocognitive deficits in domains such as working memory that implicate prefrontal systems. However, the relationship between these biomarkers and psychopathological markers such as schizotypy has not been systematically assessed, particularly in adolescent offspring of schizophrenia patients. Convergence between these markers may identify individuals at especially high risk for schizophrenia. In the current study the authors assessed whether functional deficits in working memory assessed using the oculomotor delayed response task (ODR) and executive function assessed using the Wisconsin Card Sort task (WCST), and structural deficits in prefrontal cortex, in the adolescent offspring of patients were predictive of schizotypy. Schizotypal offspring made more perseverative errors on the WCST (p<.002) and showed age-related deficits on the ODR task (p<.02) compared to their non-schizotypal counterparts or healthy controls. Reduced gray matter concentration in prefrontal cortex (p<.001) was also associated with schizotypy. Schizotypy in offspring of schizophrenia patients appears to be highly associated with known biomarkers of the illness such as executive function impairment and reductions in cortical gray matter. Furthermore, schizotypy appears to interact with development leading to greater impairment in working memory in schizotypal offspring closer to the typical age of onset of schizophrenia than non-schizotypal offspring. Thus, clinical and neurocognitive biomarkers of the illness appear to be highly interrelated in this sample of at-risk offspring. We propose that schizotypy may define a hyper vulnerable sub-sample among individuals genetically predisposed to schizophrenia and that future studies that attempt to assess risk may benefit from such a convergent approach.
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Affiliation(s)
- Vaibhav A Diwadkar
- Depatment of Psychiatry and Behavioral Neuroscience, Wayne State University School of Medicine, Detroit, MI 48201, USA.
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Bramon E, McDonald C, Croft RJ, Landau S, Filbey F, Gruzelier JH, Sham PC, Frangou S, Murray RM. Is the P300 wave an endophenotype for schizophrenia? A meta-analysis and a family study. Neuroimage 2005; 27:960-8. [PMID: 16009570 DOI: 10.1016/j.neuroimage.2005.05.022] [Citation(s) in RCA: 151] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2005] [Revised: 04/07/2005] [Accepted: 05/05/2005] [Indexed: 12/21/2022] Open
Abstract
INTRODUCTION We assessed the usefulness of the P300 wave as endophenotype for schizophrenia by means of a meta-analysis of the literature as well as our own family study. METHOD Meta-analysis: We conducted a systematic search for articles published between 1983 and 2003 that reported P300 measures in non-psychotic relatives of schizophrenic patients and in healthy controls. Meta-regression analyses were performed using a random effects procedure. The pooled standardized effect size (PSES) was calculated as the difference between the means of the two groups divided by the common standard deviation. Local study: We examined the P300 wave with a standard two-tone oddball paradigm in 30 patients with schizophrenia, 40 non-psychotic relatives, and 40 controls using linear mixed models. RESULTS Meta-analysis: We pooled 472 relatives and 513 controls. The P300 amplitude was significantly reduced in relatives (PSES = 0.61; 95% CI: 0.30 to 0.91; P < 0.001). The P300 latency was significantly delayed in relatives (PSES of -0.50; 95% CI: -0.88 to -0.13; P = 0.009]. Local study: The patients showed a trend for amplitude reductions (P = 0.06) and significant latency delays (P < 0.01). The relatives displayed normal amplitude but had significant latency delays (P = 0.01). The P300 amplitude and especially the P300 latency are promising alternative phenotypes for genetic research into schizophrenia.
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Affiliation(s)
- Elvira Bramon
- Institute of Psychiatry, P.O. box 63, De Crespigny Park, London SE5 8AF, UK.
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Kiang M, Kutas M. Association of schizotypy with semantic processing differences: an event-related brain potential study. Schizophr Res 2005; 77:329-42. [PMID: 15919182 DOI: 10.1016/j.schres.2005.03.021] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2005] [Revised: 03/21/2005] [Accepted: 03/24/2005] [Indexed: 10/25/2022]
Abstract
Disorganized speech in both schizophrenia and schizotypy has been hypothesized to result from abnormalities in how concepts activate one another in semantic memory. To study whether schizotypy is associated with differences in how categories activate their exemplars, we examined the N400 component of the event-related brain potential (ERP) elicited during a category-verification task. ERPs were recorded in young adults from the general population while they viewed category definitions each followed by a target that was either a high-typicality exemplar, low-typicality exemplar, or non-exemplar; participants' task was to indicate whether or not the target belonged to the category. Schizotypy was assessed via the Schizotypal Personality Questionnaire (SPQ). Overall, N400 amplitude was largest for non-exemplars, smallest for high-typicality exemplars, and intermediate for low-typicality exemplars. SPQ score was associated with decreased N400 amplitude to non-exemplars, and increased amplitude to both types of exemplars. SPQ score was negatively correlated with the N400 amplitude difference between non-exemplars and both low- and high-typicality exemplars, but was not correlated with the amplitude difference between low- and high-typicality exemplars. N400 amplitude differences between non-exemplars and both types of exemplars were correlated with the SPQ Interpersonal factor, but not the Disorganized factor. The results are consistent with an association of schizotypy with decreased use of context to activate related items and inhibit unrelated items.
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Affiliation(s)
- Michael Kiang
- Department of Cognitive Science, University of California-San Diego, 9500 Gilman Dr., Mail Code 0515, La Jolla, CA 92093-0515, USA.
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Korostenskaja M, Dapsys K, Siurkute A, Maciulis V, Ruksenas O, Kähkönen S. Effects of olanzapine on auditory P300 and mismatch negativity (MMN) in schizophrenia spectrum disorders. Prog Neuropsychopharmacol Biol Psychiatry 2005; 29:543-8. [PMID: 15866356 DOI: 10.1016/j.pnpbp.2005.01.019] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/28/2005] [Indexed: 11/20/2022]
Abstract
We investigated effects of olanzapine (5-10 mg/day) on passive and active attention in 11 patients with schizophrenia spectrum disorders and 15 healthy controls by using auditory evoked potentials (AEPs) mismatch negativity (MMN) and P300. AEPs were elicited during active and passive auditory "oddball" paradigms before, after 2 weeks and 4 weeks of olanzapine treatment. Baseline P300 amplitudes, but not MMN, were significantly reduced in patients compared with controls. Although clinical signs improved significantly measured by Positive and Negative Syndrome Scale (PANSS), olanzapine had no significant effects on latencies and amplitudes of MMN and P300. Thus, olanzapine does not have effects on active and passive attention in patients with schizophrenia spectrum disorders. Four weeks olanzapine treatment may be insufficient for the improvement of cognitive dysfunction in terms of inability to focus on relevant stimuli in these patients.
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Affiliation(s)
- Milena Korostenskaja
- Department of Electrophysiology, Republican Vilnius Psychiatric Hospital, Parko-15, Vilnius, LT-2041, Lithuania.
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