title: Dysfunctional Patterns of Gamma-Band Activity in Response to Human Faces Compared to Non-Facial Stimuli in Patients with Schizophrenia.
abstract: OBJECTIVE
  Healthy individuals show stronger gamma-band activities (GBAs) for socially relevant stimuli (human faces) than for non-relevant ones. This study aimed to examine whether this gamma-band preference occurs in patients with schizophrenia.
  
  
  METHODS
  EEG was recorded for 24 patients with schizophrenia and 23 healthy controls while they viewed pictures of human faces, chairs, and nature scenes. The spectral powers of high-beta (20-30 Hz) and gamma (30-80 Hz) frequencies were analyzed along 3 midline cortical regions, and phase synchronization was calculated.
  
  
  RESULTS
  Compared to the response to non-facial stimuli, higher event related deactivation to facial stimuli was observed for the high-beta frequency across groups. For the gamma frequency, early-stage GBA was increased and late-stage GBA was decreased for all 3 stimuli in patients with schizophrenia compared to healthy controls. Preferential GBA patterns (100-200 and 200-300 ms) were found in healthy controls, but not in patients with schizophrenia. Significant correlation existed between negative symptoms and GBA in the frontal region for chair and scene stimuli. There was no significant intergroup difference in phase synchronization pattern.
  
  
  CONCLUSIONS
  Our results suggest that patients with schizophrenia have deficits in the preferential pattern of GBA for human faces and the deficits in the preferential pattern were mainly influenced by over-response to socially non-relevant stimuli.
authors.affiliation: Department of Psychiatry, Inje University Ilsan Paik Hospital, Goyang, Republic of Korea.; Clinical Emotion and Cognition Research Laboratory, Goyang, Republic of Korea.
authors.forename: Seung-Hwan
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Clinical Emotion and Cognition Research Laboratory, Goyang, Republic of Korea.
authors.forename: Sangrae
authors.initials: S
authors.lastname: Kim
authors.affiliation: Clinical Emotion and Cognition Research Laboratory, Goyang, Republic of Korea.; Department of Biomedical Engineering, Hanyang University, Seoul, Republic of Korea.
authors.forename: Mi-Seon
authors.initials: MS
authors.lastname: Shim
authors.affiliation: Clinical Emotion and Cognition Research Laboratory, Goyang, Republic of Korea.; Department of Biomedical Engineering, Hanyang University, Seoul, Republic of Korea.
authors.forename: Do-Won
authors.initials: DW
authors.lastname: Kim
authors.affiliation: Department of Biomedical Engineering, Hanyang University, Seoul, Republic of Korea.
authors.forename: Chang-Hwan
authors.initials: CH
authors.lastname: Im
keywords: Gamma-band activity; High-beta-band activity; Human faces; Phase synchronization; Schizophrenia