Title
Delineating psychomotor slowing from reduced processing speed in schizophrenia
Author
Faculty/Department
Faculty of Medicine and Health Sciences
Publication type
article
Publication
Hove ,
Subject
Human medicine
Source (journal)
Cognitive neuropsychiatry. - Hove
Volume/pages
13(2008) :6 , p. 457-471
ISSN
1354-6805
vabb
c:vabb:289573
Carrier
E
Target language
English (eng)
Full text (Publishers DOI)
Affiliation
University of Antwerp
Abstract
Introduction. Psychomotor slowing is an intrinsic feature of schizophrenia that is poorly delineated from generally reduced processing speed. Although the Symbol Digit Substitution Test (SDST) is widely used to assess psychomotor speed, the task also taps several higher-order cognitive processes. Recording motor performance on copying tasks using a digitising tablet allows a more precise measurement of psychomotor speed. Methods. A group of 75 schizophrenic inpatients were compared to 26 healthy controls in their performance on the SDST and two copying tasks. Results. Factor analyses showed that the copying tasks were found to capture both a cognitively loaded factor and the motor component of psychomotor slowing better, which latter aspect is not properly assessed by the SDST. Conclusions. In schizophrenia psychomotor slowing seems to exist alongside reduced processing speed.
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