title: Reduced frontal theta oscillations indicate altered crossmodal prediction error processing in schizophrenia.
abstract: Our brain generates predictions about forthcoming stimuli and compares predicted with incoming input. Failures in predicting events might contribute to hallucinations and delusions in schizophrenia (SZ). When a stimulus violates prediction, neural activity that reflects prediction error (PE) processing is found. While PE processing deficits have been reported in unisensory paradigms, it is unknown whether SZ patients (SZP) show altered crossmodal PE processing. We measured high-density electroencephalography and applied source estimation approaches to investigate crossmodal PE processing generated by audiovisual speech. In SZP and healthy control participants (HC), we used an established paradigm in which high- and low-predictive visual syllables were paired with congruent or incongruent auditory syllables. We examined crossmodal PE processing in SZP and HC by comparing differences in event-related potentials and neural oscillations between incongruent and congruent high- and low-predictive audiovisual syllables. In both groups event-related potentials between 206 and 250 ms were larger in high- compared with low-predictive syllables, suggesting intact audiovisual incongruence detection in the auditory cortex of SZP. The analysis of oscillatory responses revealed theta-band (4-7 Hz) power enhancement in high- compared with low-predictive syllables between 230 and 370 ms in the frontal cortex of HC but not SZP. Thus aberrant frontal theta-band oscillations reflect crossmodal PE processing deficits in SZ. The present study suggests a top-down multisensory processing deficit and highlights the role of dysfunctional frontal oscillations for the SZ psychopathology.
authors.affiliation: Department of Psychiatry and Psychotherapy, Charité-Universitätsmedizin Berlin Hospital, St. Hedwig Hospital, Berlin, Germany; and yadira.roa-romero@charite.de.
authors.forename: Yadira
authors.initials: Y
authors.lastname: Roa Romero
authors.affiliation: Department of Psychiatry and Psychotherapy, Charité-Universitätsmedizin Berlin Hospital, St. Hedwig Hospital, Berlin, Germany; and.
authors.forename: Julian
authors.initials: J
authors.lastname: Keil
authors.affiliation: Department of Psychiatry and Psychotherapy, Charité-Universitätsmedizin Berlin Hospital, St. Hedwig Hospital, Berlin, Germany; and.
authors.forename: Johanna
authors.initials: J
authors.lastname: Balz
authors.affiliation: Department for Psychiatry and Psychotherapy, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Gallinat
authors.affiliation: Department of Psychiatry and Psychotherapy, Charité-Universitätsmedizin Berlin Hospital, St. Hedwig Hospital, Berlin, Germany; and.
authors.forename: Daniel
authors.initials: D
authors.lastname: Senkowski
mesh_terms: D000328:Adult; D059031:Anticipation, Psychological / Q000502:physiology*; D005071:Evoked Potentials; D000066499:Facial Recognition / Q000502:physiology; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology*; D006801:Humans; D008297:Male; D009039:Motion Perception / Q000502:physiology; D009483:Neuropsychological Tests; D012559:Schizophrenia / Q000188:drug therapy / Q000503:physiopathology*; D012565:Schizophrenic Psychology; D012815:Signal Processing, Computer-Assisted; D013067:Speech Perception / Q000502:physiology; D013826:Theta Rhythm; D013850:Thinking / Q000502:physiology; D014741:Video Recording
keywords: audiovisual speech; multisensory processing; neural synchrony; oscillatory activity; predictive coding