OBJECTIVE: Prefrontal dysfunction is considered a fundamental characteristic of schizophrenia. Recent electrophysiological evidence points to a major instability of signal processing in prefrontal cortical microcircuits because of reduced phase-synchronization (i.e., an increased stimulus-related variability [noise] of single-trial responses in the spatial and time domain). The authors used functional magnetic resonance imaging (fMRI) during a visual two-choice reaction task in order to measure, with higher topographic accuracy, signal stability in patients with schizophrenia and its relationship to more traditional measures of activation. METHOD: Twelve clinically stable inpatients with schizophrenia and 16 matched comparison subjects were evaluated. Event-related blood-oxygen-level-dependent responses were subjected to an analysis of residual noise variance and to independent data dimension independent component analysis in the medial prefrontal cortex. RESULTS: In patients with schizophrenia, the authors found increased residual noise variance of the blood-oxygen-level-dependent response that predicted the level of prefrontal activation in these subjects. In the left hemisphere, residual noise variance strongly correlated with psychotic symptoms. Independent component analysis revealed a "fractionized" and unfocussed pattern of activation in patients. CONCLUSIONS: These findings suggest that unstable cortical signal processing underlies classic abnormal cortical activation patterns as well as psychosis in schizophrenia.
OBJECTIVE:Prefrontal dysfunction is considered a fundamental characteristic of schizophrenia. Recent electrophysiological evidence points to a major instability of signal processing in prefrontal cortical microcircuits because of reduced phase-synchronization (i.e., an increased stimulus-related variability [noise] of single-trial responses in the spatial and time domain). The authors used functional magnetic resonance imaging (fMRI) during a visual two-choice reaction task in order to measure, with higher topographic accuracy, signal stability in patients with schizophrenia and its relationship to more traditional measures of activation. METHOD: Twelve clinically stable inpatients with schizophrenia and 16 matched comparison subjects were evaluated. Event-related blood-oxygen-level-dependent responses were subjected to an analysis of residual noise variance and to independent data dimension independent component analysis in the medial prefrontal cortex. RESULTS: In patients with schizophrenia, the authors found increased residual noise variance of the blood-oxygen-level-dependent response that predicted the level of prefrontal activation in these subjects. In the left hemisphere, residual noise variance strongly correlated with psychotic symptoms. Independent component analysis revealed a "fractionized" and unfocussed pattern of activation in patients. CONCLUSIONS: These findings suggest that unstable cortical signal processing underlies classic abnormal cortical activation patterns as well as psychosis in schizophrenia.
Authors: Magali Comte; Aïda Cancel; Jennifer T Coull; Daniele Schön; Emmanuelle Reynaud; Sarah Boukezzi; Pierre-François Rousseau; Gabriel Robert; Stéphanie Khalfa; Eric Guedj; Olivier Blin; Daniel R Weinberger; Eric Fakra Journal: Hum Brain Mapp Date: 2015-02-09 Impact factor: 5.038
Authors: Matthew E Hudgens-Haney; Lauren E Ethridge; Jennifer E McDowell; Sarah K Keedy; Godfrey D Pearlson; Carol A Tamminga; Matcheri S Keshavan; John A Sweeney; Brett A Clementz Journal: Schizophr Res Date: 2017-08-24 Impact factor: 4.939
Authors: Juan L Molina; Bradley Voytek; Michael L Thomas; Yash B Joshi; Savita G Bhakta; Jo A Talledo; Neal R Swerdlow; Gregory A Light Journal: Biol Psychiatry Cogn Neurosci Neuroimaging Date: 2020-02-22
Authors: Daniel C Javitt; Kevin M Spencer; Gunvant K Thaker; Georg Winterer; Mihály Hajós Journal: Nat Rev Drug Discov Date: 2008-01 Impact factor: 84.694