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Optimal linear weighting of eye tracking, CPT, and backward masking deficits in discriminating schizophrenic patients and normal controls
Schizophrenia I
BIOL PSYCHIATRY 1990;27:41A-179A
49A
18 SENSORIMOTOR DEFICITS AND INCREASED WISCONSIN CARD SORTING TEST PERSEVERATIONS IN SCHIZOPHRENIA David Braff, M.D., Melissa Jenkins, B.A., Christian Grillon, Ph.D., Mark A. Geyer, Ph.D., Robert W. Butler, Ph.D. University of California--San Diego, Department of Psychiatry, La Jolla, CA 92093. Sensorimotor-gating deficits have been identified in schizophrenic patients using ERP P50 gating and prepulse inhibition (PPl) of startle paradigms. In these paradigms, schizophrenic patients show deficient inhibitory processes and also show increased perseverative responses (PRs) on the Wisconsin Card Sorting Test (WCST) that can reflect a failure of frontal lobe-related inhibitory processes. This study was designated to test the hypothesis that those schizophrenic patients with inflated PRs on the WCST would show maximal gating deficits due to the hypothesized failure of frontal lobe functioning that may reflect an associated increase in subcortical dopamine Zone that reciprocally inhibits frontal efficiency. We evaluated PPI by the ability of a weak prestimulus to inhibit the obicularis occuli component of the human startle reflex to a 118 dB tone. The schizophrenic group (n = 39) had significantly deficient PPl and increased PRs compared with the normal group (n = 39) by ANOVA. Schizophrenic patients with inflated PRs had significantly less gating than those patients with noninflated PRs, which supports our hypothesis. Related animal studies will be presented to illuminate the neurobiological deficits of some schizophrenic patients.
19 OPTIMAL LINEAR WEIGHTING OF EYE TRACKING, CPT, AND BACKWARD MASKING DEFICITS IN DISCRIMINATING SCHIZOPHRENIC PATIENTS AND NORMAL CONTRC~LS Richard S.E. Keefe, M.A., Richard C. Mobs, Ph.D., Larry J. Siever, M.D., Jaekie Moskowitz, M.D. (by invitation), Philip D. Harvey, Ph.D., Harold A. Saekeim, Ph.D., Kenneth L. David, M.D. Mount Sinai School of Medicine, and Psychiatry Service, Veterans Affairs Medical Center, Bronx, NY 10468. Schizophrenics perform worse than controls on eye tracking, continuous performance test (CPT), and backward masking tasks. The relative importance and discriminating power of these deficits in schizophrenia has been largely unaddressed. This study tested the optimal linear weighting of key variables yielded from monitor and nonmonitor eye tracking tasks, degraded and nondegraded CPT, and a backward masking paradigm. Data were collected from 32 DSM-III-R chronic schizophrenics and 17 normal controls. Performanc¢ on all tasks contributed significantly (p < 0.01) to the discriminant function, and 82% of subjects were correctly classified. CPT response sensitivity (d') was the most powerful di.~criminating variable, yielding structure coefficients of 0.88 for nondegraded and 0.70 for degraded conditions. Structure coefficients were 0.47 and 0.43 for monitor and nonmonitor eye tracking qualitative ratings, and 0.51 and 0.42 for backward masking performance at 120 and 180 msec stimulus onset asynchronies. The implications of the results for neurocognitive models of schizophrenia will be discussed.
BIOL PSYCHIATRY 1990;27:41A-179A
49A
18 SENSORIMOTOR DEFICITS AND INCREASED WISCONSIN CARD SORTING TEST PERSEVERATIONS IN SCHIZOPHRENIA David Braff, M.D., Melissa Jenkins, B.A., Christian Grillon, Ph.D., Mark A. Geyer, Ph.D., Robert W. Butler, Ph.D. University of California--San Diego, Department of Psychiatry, La Jolla, CA 92093. Sensorimotor-gating deficits have been identified in schizophrenic patients using ERP P50 gating and prepulse inhibition (PPl) of startle paradigms. In these paradigms, schizophrenic patients show deficient inhibitory processes and also show increased perseverative responses (PRs) on the Wisconsin Card Sorting Test (WCST) that can reflect a failure of frontal lobe-related inhibitory processes. This study was designated to test the hypothesis that those schizophrenic patients with inflated PRs on the WCST would show maximal gating deficits due to the hypothesized failure of frontal lobe functioning that may reflect an associated increase in subcortical dopamine Zone that reciprocally inhibits frontal efficiency. We evaluated PPI by the ability of a weak prestimulus to inhibit the obicularis occuli component of the human startle reflex to a 118 dB tone. The schizophrenic group (n = 39) had significantly deficient PPl and increased PRs compared with the normal group (n = 39) by ANOVA. Schizophrenic patients with inflated PRs had significantly less gating than those patients with noninflated PRs, which supports our hypothesis. Related animal studies will be presented to illuminate the neurobiological deficits of some schizophrenic patients.
19 OPTIMAL LINEAR WEIGHTING OF EYE TRACKING, CPT, AND BACKWARD MASKING DEFICITS IN DISCRIMINATING SCHIZOPHRENIC PATIENTS AND NORMAL CONTRC~LS Richard S.E. Keefe, M.A., Richard C. Mobs, Ph.D., Larry J. Siever, M.D., Jaekie Moskowitz, M.D. (by invitation), Philip D. Harvey, Ph.D., Harold A. Saekeim, Ph.D., Kenneth L. David, M.D. Mount Sinai School of Medicine, and Psychiatry Service, Veterans Affairs Medical Center, Bronx, NY 10468. Schizophrenics perform worse than controls on eye tracking, continuous performance test (CPT), and backward masking tasks. The relative importance and discriminating power of these deficits in schizophrenia has been largely unaddressed. This study tested the optimal linear weighting of key variables yielded from monitor and nonmonitor eye tracking tasks, degraded and nondegraded CPT, and a backward masking paradigm. Data were collected from 32 DSM-III-R chronic schizophrenics and 17 normal controls. Performanc¢ on all tasks contributed significantly (p < 0.01) to the discriminant function, and 82% of subjects were correctly classified. CPT response sensitivity (d') was the most powerful di.~criminating variable, yielding structure coefficients of 0.88 for nondegraded and 0.70 for degraded conditions. Structure coefficients were 0.47 and 0.43 for monitor and nonmonitor eye tracking qualitative ratings, and 0.51 and 0.42 for backward masking performance at 120 and 180 msec stimulus onset asynchronies. The implications of the results for neurocognitive models of schizophrenia will be discussed.