Cognitive subprocesses and schizophrenia. A. Reaction-time decomposition.
OBJECTIVE
The aim of the study is to demonstrate that deficits of information processing in schizophrenic patients can be isolated with reaction-time (RT) decomposition paradigms.


METHODS
Three types of visually presented tasks were applied: simple, disjunctive and choice RT-tasks. RT were split into movement latency and time necessary to execute movements. Comparisons of three samples of schizophrenic patients (295.3) with individually matched (age, sex. education and handedness) healthy controls are presented: Sample 1: 10 drug-naive first-onset patients, Sample 2: 10 neuroleptically treated first-onset patients, Sample 3: 10 neuroleptically treated chronically ill patients.


RESULTS
Findings indicate that schizophrenia affects primarily subprocesses in which percepts are translated into appropriate actions (response-selection). Neuroleptic treatment improves processing at this stage but is accompanied by slowing of movement execution.


CONCLUSIONS
Response-selection is selectively impaired in first-onset patients. This disturbance, which might be specific for schizophrenia, can be regarded as indication of a disconnection between frontal and posterior areas.
Krieger
S
S
Centre for Psychiatry, Justus-Liebig-University Giessen, Germany.
Lis
S
S
Gallhofer
B
B
D000328:Adult; D002908:Chronic Disease; D003072:Cognition Disorders / Q000175:diagnosis* / Q000209:etiology*; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D010775:Photic Stimulation; D011930:Reaction Time; D012494:Sampling Studies; D012559:Schizophrenia / Q000150:complications* / Q000503:physiopathology; D012565:Schizophrenic Psychology