BACKGROUND: The present study was designed to assess, using event-related potentials, whether aberrant semantic processing reported in schizophrenia results from primary semantic overactivation or contextual dysregulation. METHODS: The visual event-related brain potentials were compared between 9 schizophrenic subjects and 16 normal control subjects performing two kinds of semantic categorization tasks with different nontarget stimuli: 1) nontargets comprising words, pseudowords, and unpronounceable foreign letters and 2) nontargets comprising initial presenting words, immediate repetition words, and delayed repetition words. RESULTS: Schizophrenic subjects showed no evidence suggestive of a greater negative potential associated with words and pseudowords, but they did show a lack of amplitude change associated with immediately repeated words relative to that in control subjects. CONCLUSIONS: These results suggest that aberrant semantic activation in schizophrenia results mainly from a failure to utilize information from preceding words or context, and could explain the increased N400 to the congruent or related words recently reported in this disease.
BACKGROUND: The present study was designed to assess, using event-related potentials, whether aberrant semantic processing reported in schizophrenia results from primary semantic overactivation or contextual dysregulation. METHODS: The visual event-related brain potentials were compared between 9 schizophrenic subjects and 16 normal control subjects performing two kinds of semantic categorization tasks with different nontarget stimuli: 1) nontargets comprising words, pseudowords, and unpronounceable foreign letters and 2) nontargets comprising initial presenting words, immediate repetition words, and delayed repetition words. RESULTS:Schizophrenic subjects showed no evidence suggestive of a greater negative potential associated with words and pseudowords, but they did show a lack of amplitude change associated with immediately repeated words relative to that in control subjects. CONCLUSIONS: These results suggest that aberrant semantic activation in schizophrenia results mainly from a failure to utilize information from preceding words or context, and could explain the increased N400 to the congruent or related words recently reported in this disease.
Authors: Jürgen Kayser; Craig E Tenke; Christopher J Kroppmann; Shiva Fekri; Daniel M Alschuler; Nathan A Gates; Roberto Gil; Jill M Harkavy-Friedman; Lars F Jarskog; Gerard E Bruder Journal: Int J Psychophysiol Date: 2009-12-06 Impact factor: 2.997
Authors: Anthony P Weiss; Cameron B Ellis; Joshua L Roffman; Steven Stufflebeam; Matti S Hamalainen; Margaret Duff; Donald C Goff; Daniel L Schacter Journal: J Neurosci Date: 2009-09-09 Impact factor: 6.167
Authors: Andreas Sauer; Tineke Grent-'t-Jong; Michael Wibral; Michael Grube; Wolf Singer; Peter J Uhlhaas Journal: Front Psychiatry Date: 2020-11-23 Impact factor: 4.157