title: Mapping auditory hallucinations in schizophrenia using functional magnetic resonance imaging.
abstract: BACKGROUND
  Perceptions of speech in the absence of an auditory stimulus (auditory verbal hallucinations) are a cardinal feature of schizophrenia. Functional neuroimaging provides a powerful means of measuring neural activity during auditory hallucinations, but the results from previous studies have been inconsistent. This may reflect the acquisition of small numbers of images in each subject and the confounding effects of patients actively signaling when hallucinations occur.
  
  
  METHODS
  We examined 6 patients with schizophrenia who were experiencing frequent auditory hallucinations, using a novel functional magnetic resonance imaging method that permitted the measurement of spontaneous neural activity without requiring subjects to signal when hallucinations occurred. Approximately 50 individual scans were acquired at unpredictable intervals in each subject while they were intermittently hallucinating. Immediately after each scan, subjects reported whether they had been hallucinating at that instant. Neural activity when patients were and were not experiencing hallucinations was compared in each subject and the group as a whole.
  
  
  RESULTS
  Auditory hallucinations were associated with activation in the inferior frontal/insular, anterior cingulate, and temporal cortex bilaterally (with greater responses on the right), the right thalamus and inferior colliculus, and the left hippocampus and parahippocampal cortex (P<.0001).
  
  
  CONCLUSIONS
  Auditory hallucinations may be mediated by a distributed network of cortical and subcortical areas. Previous neuroimaging studies of auditory hallucinations may have identified different components of this network.
authors.affiliation: Wellcome Clinical Fellow, Division of Psychological Medicine, Institute of Psychiatry, De Crespigny Park, Denmark Hill, London SE5 8AF, United Kingdom. s.shergill@iop.kcl.ac.uk
authors.forename: S S
authors.initials: SS
authors.lastname: Shergill
authors.forename: M J
authors.initials: MJ
authors.lastname: Brammer
authors.forename: S C
authors.initials: SC
authors.lastname: Williams
authors.forename: R M
authors.initials: RM
authors.lastname: Murray
authors.forename: P K
authors.initials: PK
authors.lastname: McGuire
mesh_terms: D001307:Auditory Perception / Q000502:physiology*; D001931:Brain Mapping; D006212:Hallucinations / Q000175:diagnosis* / Q000503:physiopathology* / Q000523:psychology; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000706:statistics & numerical data*; D012559:Schizophrenia / Q000175:diagnosis* / Q000503:physiopathology*; D012565:Schizophrenic Psychology