Cognitive processing efficiency in schizophrenia: generalized vs domain specific deficits.
The issue of generalized vs specific cognitive deficits in schizophrenia was explored by examining reaction time data from 40 published studies with 196 reaction time conditions. Using a regression-based approach, the proportional relationship between the response times of groups with schizophrenia was compared with those of age-matched, healthy comparison groups. Through this method, the extent to which deficits in processing efficiency are explained by a single factor, general processing speed, was compared with possible domain specific or task specific deficits. The results suggest that, overall, the data conforms well to a general linear slowing model which accounts for 87% of the variance in reaction time performance. Some additional variance, however, is accounted for by different degrees of linear slowing for three types of tasks: tasks involving selective attention/inhibition showed the most slowing (2.3-times slower for schizophrenia), followed by lexical tasks (1.8-times slower for schizophrenia), and finally, non-lexical tasks showed the least slowing (1.4-times slower for schizophrenia). This pattern is distinct from other groups showing generalized slowing, such as older adults, and suggests a unique pattern of information processing deficits in schizophrenia.
Schatz
J
J
Department of Psychology, Washington University of St. Louis, Missouri, USA. jschatz@itsa.ucsf.edu
D000328:Adult; D003072:Cognition Disorders / Q000175:diagnosis / Q000209:etiology*; D006801:Humans; D011930:Reaction Time; D012559:Schizophrenia / Q000150:complications*