title: Altered parallel auditory processing in schizophrenia patients.
abstract: Patients with schizophrenia have impaired auditory processing that has been demonstrated by diminished P50 response to paired auditory stimuli in event-related potential (ERP) studies. Cerebral processing can also be studied with magnetoencephalography (MEG). With a whole-head MEG, which enables one to simultaneously measure brain activity in both hemispheres, we investigated whether early parallel auditory processing is impaired in schizophrenia. Sequences of tones were monaurally presented to schizophrenia patients and healthy controls in a passive condition, and the event-related magnetic fields were recorded simultaneously over both auditory cortices. The interhemispheric latency difference of the P50m, but not that of the N100m, was significantly shorter in the patient group in the right-ear but not in the left-ear stimulus condition. Further, the ipsilateral P50m was significantly earlier in schizophrenia patients in the right-ear condition. This result suggests that schizophrenia affects the consecutive preconscious auditory processing in a different manner.
authors.affiliation: Department of Psychology, University of Helsinki, Medical Engineering Centre, Helsinki University Central Hospital, Finland.
authors.forename: E
authors.initials: E
authors.lastname: Pekkonen
authors.forename: M
authors.initials: M
authors.lastname: Huotilainen
authors.forename: H
authors.initials: H
authors.lastname: Katila
authors.forename: J
authors.initials: J
authors.lastname: Karhu
authors.forename: R
authors.initials: R
authors.lastname: Näätänen
authors.forename: J
authors.initials: J
authors.lastname: Tiihonen
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001303:Auditory Cortex / Q000503:physiopathology*; D001306:Auditory Pathways / Q000503:physiopathology*; D001526:Behavioral Symptoms / Q000503:physiopathology; D016022:Case-Control Studies; D004569:Electroencephalography / Q000379:methods; D004574:Electromagnetic Fields; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011930:Reaction Time / Q000502:physiology; D012559:Schizophrenia / Q000503:physiopathology*