title: Time course of regional brain activity accompanying auditory verbal hallucinations in schizophrenia.
abstract: BACKGROUND
  The pathophysiology of auditory verbal hallucinations remains poorly  understood.
  
  
  OBJECTIVE
  To characterise the time course of regional brain activity leading to  auditory verbal hallucinations.
  
  
  METHODS
  During functional magnetic resonance imaging, 11 patients with  schizophrenia or schizoaffective disorder signalled auditory verbal  hallucination events by pressing a button. To control for effects of motor  behaviour, regional activity associated with hallucination events was scaled  against corresponding activity arising from random button-presses produced by  10 patients who did not experience hallucinations.
  
  
  RESULTS
  Immediately prior to the hallucinations, motor-adjusted activity in the  left inferior frontal gyrus was significantly greater than corresponding  activity in the right inferior frontal gyrus. In contrast, motor-adjusted  activity in a right posterior temporal region overshadowed corresponding  activity in the left homologous temporal region. Robustly elevated  motor-adjusted activity in the left temporal region associated with auditory  verbal hallucinations was also detected, but only subsequent to hallucination  events. At the earliest time shift studied, the correlation between left  inferior frontal gyrus and right temporal activity was significantly higher  for the hallucination group compared with non-hallucinating patients.
  
  
  CONCLUSIONS
  Findings suggest that heightened functional coupling between the left  inferior frontal gyrus and right temporal regions leads to coactivation in  these speech processing regions that is hallucinogenic. Delayed left temporal  activation may reflect impaired corollary discharge contributing to source  misattribution of resulting verbal images.
authors.affiliation: Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut, USA. ralph.hoffman@yale.edu
authors.forename: Ralph E
authors.initials: RE
authors.lastname: Hoffman
authors.forename: Brian
authors.initials: B
authors.lastname: Pittman
authors.forename: R Todd
authors.initials: RT
authors.lastname: Constable
authors.forename: Zubin
authors.initials: Z
authors.lastname: Bhagwagar
authors.forename: Michelle
authors.initials: M
authors.lastname: Hampson
mesh_terms: D000328:Adult; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology; D006212:Hallucinations / Q000503:physiopathology*; D006439:Hemodynamics; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D010100:Oxygen / Q000097:blood; D012559:Schizophrenia / Q000503:physiopathology*; D012565:Schizophrenic Psychology; D013702:Temporal Lobe / Q000503:physiopathology; D013997:Time Factors
chemical_list: D010100:Oxygen