title: Greater neuronal responses during automatic semantic processing in schizophrenia.
abstract: A core feature of schizophrenia is a disturbance of associative processes. To date, no functional MRI studies have investigated semantic priming in schizophrenia under experimental conditions that measure automatic, as opposed to strategic, processing. The present study's focus was to investigate hemodynamic responses during indirect semantic priming at a short stimulus onset asynchrony (i.e., 350 ms), conditions which are considered to be a particularly sensitive measure of automatic spreading activation during semantic processing and of the associative disturbances in schizophrenia. Seventeen individuals with DSM-IV, schizophrenia and 15 comparison participants underwent functional scanning while performing a lexical decision task on directly related, indirectly related, unrelated, and word/nonword pairs. A random-effects region of interest analysis within a priori temporal and frontal regions was performed. Whereas comparison individuals exhibited hemodynamic suppression in response to priming, individuals with schizophrenia exhibited hemodynamic enhancement. Relative to the comparison group, these enhancements were observed in the left fusiform and superior temporal gyri for indirectly related word pairs relative to unrelated pairs. Greater priming-related responses within temporal regions may reflect increased and prolonged automatic spreading activation during semantic processing in schizophrenia.
authors: Department of Psychiatry, University of Colorado Denver, Aurora 80045, USA. lisa.wilson@ucdenver.edu
authors: Lisa B
authors: LB
authors: Wilson
authors: Donald C
authors: DC
authors: Rojas
authors: Shireen
authors: S
authors: Shatti
authors: Jason R
authors: JR
authors: Tregellas
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001921:Brain / Q000098:blood supply / Q000503:physiopathology*; D001931:Brain Mapping; D003657:Decision Making; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood; D011578:Psycholinguistics; D011930:Reaction Time / Q000502:physiology; D012559:Schizophrenia / Q000473:pathology* / Q000503:physiopathology; D012660:Semantics
chemical_list: D010100:Oxygen
references: Prog Neuropsychopharmacol Biol Psychiatry. 1997 Nov;21(8):1203-29
references: 9460087
references: Neuroimage. 2002 Jan;15(1):273-89
references: 11771995
references: Arch Gen Psychiatry. 1994 Nov;51(11):849-59; discussion 863-4
references: 7944874
references: Brain Res Rev. 2009 Jun;61(1):14-32
references: 19348859
references: Appl Neuropsychol. 2006;13(1):51-7
references: 16594871
references: Nat Rev Neurosci. 2005 Apr;6(4):312-24
references: 15803162
references: Arch Gen Psychiatry. 2007 Feb;64(2):138-51
references: 17283282
references: Brain Lang. 1998 Oct 1;64(3):377-408
references: 9743549
references: Neuron. 2003 May 8;38(3):487-97
references: 12741994
references: Neuroimage. 2007 Mar;35(1):273-82
references: 17215145
references: J Exp Psychol. 1971 Oct;90(2):227-34
references: 5134329
references: Brain Res Cogn Brain Res. 1999 Oct 25;8(3):289-98
references: 10556606
references: Neuropsychopharmacology. 2001 Jul;25(1):1-27
references: 11377916
references: Psychol Med. 2001 Feb;31(2):221-9
references: 11232910
references: Neuroimage. 2005 Jul 1;26(3):839-51
references: 15955494
references: J Neurosci. 2001 May 15;21(10):3564-71
references: 11331385
references: Behav Res Methods Instrum Comput. 2004 Aug;36(3):402-7
references: 15641430