title: Regional brain activation/deactivation during word generation in schizophrenia: fMRI study.
abstract: BACKGROUND
  Examination of the brain regions that show aberrant activations and/or deactivations during semantic word generation could pave the way for a better understanding of the neurobiology of cognitive dysfunction in schizophrenia.
  
  
  OBJECTIVE
  To examine the pattern of functional magnetic resonance imaging blood oxygen level dependent activations and deactivations during semantic word generation in schizophrenia.
  
  
  METHODS
  Functional magnetic resonance imaging was performed on 24 participants with schizophrenia and 24 matched healthy controls during an overt, paced, 'semantic category word generation' condition and a baseline 'word repetition' condition that modelled all the lead-in/associated processes involved in the performance of the generation task.
  
  
  RESULTS
  The brain regions activated during word generation in healthy individuals were replicated with minimal redundancies in participants with schizophrenia. The individuals with schizophrenia showed additional activations of temporo-parieto-occipital cortical regions as well as subcortical regions, despite significantly poorer behavioural performance than the healthy participants. Importantly, the extensive deactivations in other brain regions during word generation in healthy individuals could not be replicated in those with schizophrenia.
  
  
  CONCLUSIONS
  More widespread activations and deficient deactivations in the poorly performing participants with schizophrenia may reflect an inability to inhibit competing cognitive processes, which in turn could constitute the core information-processing deficit underlying impaired word generation in schizophrenia.
authors.affiliation: Department of Psychiatry, National Institute of Mental Health and Neurosciences, Bangalore, Karnataka, India. jpj@nimhans.kar.nic.in
authors.forename: John P
authors.initials: JP
authors.lastname: John
authors.forename: Harsha N
authors.initials: HN
authors.lastname: Halahalli
authors.forename: Mandapati K
authors.initials: MK
authors.lastname: Vasudev
authors.forename: Peruvumba N
authors.initials: PN
authors.lastname: Jayakumar
authors.forename: Sanjeev
authors.initials: S
authors.lastname: Jain
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping / Q000379:methods*; D016022:Case-Control Studies; D003072:Cognition Disorders / Q000503:physiopathology / Q000523:psychology; D003627:Data Interpretation, Statistical; D005260:Female; D006439:Hemodynamics; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007807:Language Tests; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D012559:Schizophrenia / Q000503:physiopathology*; D012565:Schizophrenic Psychology; D014705:Verbal Behavior / Q000502:physiology*; D055815:Young Adult
chemical_list: D010100:Oxygen