title: Network analysis of auditory hallucinations in nonpsychotic individuals.
abstract: BACKGROUND
  Auditory verbal hallucinations (AVH) are a cardinal feature of schizophrenia and can severely disrupt behavior and decrease quality of life. Identification of areas with high functional connectivity (so-called hub regions) that are associated with the predisposition to hallucinate may provide potential targets for neuromodulation in the treatment of AVH.
  
  
  METHODS
  Resting-state fMRI scans during which no hallucinations had occurred were acquired from 29 nonpsychotic individuals with AVH and 29 matched controls. These nonpsychotic individuals with AVH provide the opportunity to study AVH without several confounds associated with schizophrenia, such as antipsychotic medication use and other symptoms related to the illness. Hub regions were identified by assessing weighted connectivity strength and betweenness centrality across groups using a permutation analysis.
  
  
  RESULTS
  Nonpsychotic individuals with AVH exhibited increased functioning as hub regions in the temporal cortices and the posterior cingulate/precuneus, which is an important area in the default mode network (DMN), compared to the nonhallucinating controls. In addition, the right inferior temporal gyrus, left paracentral lobule and right amygdala were less important as a hub region in the AVH group.
  
  
  CONCLUSIONS
  These results suggest that the predisposition to hallucinate may be related to aberrant functioning of the DMN and the auditory cortices.
authors: Department of Psychiatry, University Medical Center, Utrecht, the Netherlands and Rudolf Magnus Institute of Neuroscience, Utrecht, the Netherlands.
authors: Remko
authors: R
authors: van Lutterveld
authors: Kelly M J
authors: KM
authors: Diederen
authors: Willem M
authors: WM
authors: Otte
authors: Iris E
authors: IE
authors: Sommer
mesh_terms: D000328:Adult; D016477:Artifacts; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping / Q000379:methods; D005260:Female; D006212:Hallucinations / Q000503:physiopathology*; D006257:Head; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D009068:Movement; D012146:Rest / Q000502:physiology; D012815:Signal Processing, Computer-Assisted; D013067:Speech Perception / Q000502:physiology*
keywords: auditory hallucination; betweenness centrality; default mode network; degree; fMRI; graph theory; hub; psychosis; resting state; schizophrenia