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Schizophrenia: Deficits in abstraction, categorization, and verbal learning correlate with MRI temporal lobe abnormalities
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BIOL PSYCHIATRY 1992;31:61A-252A
Studies in Cognition and Information Processing
commission were correlated with disorganization (r = 0.40, p = 0.02). Poor backward masking performance at a stimulus onset asynchrony of 120 ms was correlated with social amotivation (r = - 0 . 4 6 , p = 0.03). On the no-mask condition, poor performance was correlated with disorganization (r = - 0 . 5 4 , p = 0.01), delusions (r = - 0 . 5 5 , p = 0.01), and bizarre behavior (r = - 0 . 4 3 , p ---- 0.05). Eye tracking was not significantly related to any of the symptoms evaluated. These data suggest that positive and negative symptoms are differentially related to neurocognitive deficits.
125 SCHIZOPHRENIA: DEFICITS IN ABSTRACTION,
CATEGORIZATION, AND VERBAL LEARNING CORRELATE WITH MRI TEMPORAL LOBE ABNORMALITIES P.G. Nestor, M. Shenton, R.W. McCarley, J. Haimson, R.S. Smith, R. Kikinis, F.A. Jolesz Harvard Medical School, Brockton MA 02140. The relationship between temporal lobe (TL) abnormalities and neuropsychological impairment was examined in 15 schizophrenic (SZ) patients who underwent both MRI and neuropsychological studies. Neuropsychological tests included (I) the Wisconsin Card Sorting Test (WCST) and the Similarities subtest of the Wechsler Adult Intelligence Scale-Revised (WAIS-R), both of which were used as measures of abstraction and categorization; and (2) Logical Memory, Visual Reproduction, and Verbal Paired Associates subtests of the Wechsler Memory Scale-Revised (WMS-R), which were used to assess various aspects of learning and memory. In addition, tests of motor dexterity (Finger Tapping Test) and constructional abilities (Block Design) were used as control tasks. Quantitative semiautomated MRI image processing techniques on a 1.5 mm SPGR imager were used to obtain volumes of left and right TL, and grey matter within the superior temporal gyms (STG), hippocampus, and parahippocampus gyms (PHG). Reduced volume in TL structures correlated with poorer scores on neuropsychologicai tests of abstraction, categorization, and verbal learning, but not with performance on control tasks of motor and constructional abilities. For example, Spearman rank correlations indicated a significant association between poorer scores on the WCST and reduced volume in the left (r = 0.69, p < 0.01) and right (r = 0.62, p < 0,05) PHG and left (r = 0.71, p < 0,01) and right (r = 0,67, p < 0.01) STG, A similar pattern of signilicant correlations was found between scores on Similarities and these TL structures. Finally, verbal paired associate learning correlated signilicantly with reduced volume in the left STG (r = 0.58, p < 0.05). Thus, neuropsychological delicits in abstraction, categorization, and verbal learning may be related to reduced volume in TL structures in patients with schizophrenia, Moreover, putative frontal lobe indicators (WCST) may reflect TL damage in SZ, perhaps as a consequence of damaged projections to the lrontal lobe.
126 PROBING FRONTAL CORTICAL FUNCTIONS: A SIMPLE
BINARY CHOICE TASK COMBINED WITH NONLINEAR DYNAMICS COMPLEXITY EVALUATION IN SCHIZOPHRENIC SUBJECTS M.P. Paulus, M.A. Geyer, D.L. Braff Universi~ of California, San Diego, La Jolla CA 92093. The deregulation of prefrontal fimctioning has been proposed as a pathophysiological basis of schizophrenic disorders. Animal experiments indicate that the prefrontal cortex is unnecessary for behavior regulated by external stimuli, as with many associative learning and recognition memory processes but may be essential for regulation of motor behavior by internalized representations. Choice task paradigms have been used to assess response sequence characteristics in animals and humans. We hypothesized that predictability and switching between response alternatives should be increased in schizophrenic subjects relative to controls. A computerized binary choice task paradigm, the "car prediction paradigm," was employed. The data set consisted of the binary choices, pushing the right (l) or left (0) mouse button, and the interresponse time
BIOL PSYCHIATRY 1992;31:61A-252A
Studies in Cognition and Information Processing
commission were correlated with disorganization (r = 0.40, p = 0.02). Poor backward masking performance at a stimulus onset asynchrony of 120 ms was correlated with social amotivation (r = - 0 . 4 6 , p = 0.03). On the no-mask condition, poor performance was correlated with disorganization (r = - 0 . 5 4 , p = 0.01), delusions (r = - 0 . 5 5 , p = 0.01), and bizarre behavior (r = - 0 . 4 3 , p ---- 0.05). Eye tracking was not significantly related to any of the symptoms evaluated. These data suggest that positive and negative symptoms are differentially related to neurocognitive deficits.
125 SCHIZOPHRENIA: DEFICITS IN ABSTRACTION,
CATEGORIZATION, AND VERBAL LEARNING CORRELATE WITH MRI TEMPORAL LOBE ABNORMALITIES P.G. Nestor, M. Shenton, R.W. McCarley, J. Haimson, R.S. Smith, R. Kikinis, F.A. Jolesz Harvard Medical School, Brockton MA 02140. The relationship between temporal lobe (TL) abnormalities and neuropsychological impairment was examined in 15 schizophrenic (SZ) patients who underwent both MRI and neuropsychological studies. Neuropsychological tests included (I) the Wisconsin Card Sorting Test (WCST) and the Similarities subtest of the Wechsler Adult Intelligence Scale-Revised (WAIS-R), both of which were used as measures of abstraction and categorization; and (2) Logical Memory, Visual Reproduction, and Verbal Paired Associates subtests of the Wechsler Memory Scale-Revised (WMS-R), which were used to assess various aspects of learning and memory. In addition, tests of motor dexterity (Finger Tapping Test) and constructional abilities (Block Design) were used as control tasks. Quantitative semiautomated MRI image processing techniques on a 1.5 mm SPGR imager were used to obtain volumes of left and right TL, and grey matter within the superior temporal gyms (STG), hippocampus, and parahippocampus gyms (PHG). Reduced volume in TL structures correlated with poorer scores on neuropsychologicai tests of abstraction, categorization, and verbal learning, but not with performance on control tasks of motor and constructional abilities. For example, Spearman rank correlations indicated a significant association between poorer scores on the WCST and reduced volume in the left (r = 0.69, p < 0.01) and right (r = 0.62, p < 0,05) PHG and left (r = 0.71, p < 0,01) and right (r = 0,67, p < 0.01) STG, A similar pattern of signilicant correlations was found between scores on Similarities and these TL structures. Finally, verbal paired associate learning correlated signilicantly with reduced volume in the left STG (r = 0.58, p < 0.05). Thus, neuropsychological delicits in abstraction, categorization, and verbal learning may be related to reduced volume in TL structures in patients with schizophrenia, Moreover, putative frontal lobe indicators (WCST) may reflect TL damage in SZ, perhaps as a consequence of damaged projections to the lrontal lobe.
126 PROBING FRONTAL CORTICAL FUNCTIONS: A SIMPLE
BINARY CHOICE TASK COMBINED WITH NONLINEAR DYNAMICS COMPLEXITY EVALUATION IN SCHIZOPHRENIC SUBJECTS M.P. Paulus, M.A. Geyer, D.L. Braff Universi~ of California, San Diego, La Jolla CA 92093. The deregulation of prefrontal fimctioning has been proposed as a pathophysiological basis of schizophrenic disorders. Animal experiments indicate that the prefrontal cortex is unnecessary for behavior regulated by external stimuli, as with many associative learning and recognition memory processes but may be essential for regulation of motor behavior by internalized representations. Choice task paradigms have been used to assess response sequence characteristics in animals and humans. We hypothesized that predictability and switching between response alternatives should be increased in schizophrenic subjects relative to controls. A computerized binary choice task paradigm, the "car prediction paradigm," was employed. The data set consisted of the binary choices, pushing the right (l) or left (0) mouse button, and the interresponse time