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Right visual field deficits in reaction time after invalid cues in chronic and never-medicated schizophrenics compared to normal controls
Studies in Clinical and ExperimentalNeuropsychology
BIOLPSYCHIATRY 1989;25:14A-79A
77A
information processing dysfunction of schizophrenic (N = 70) versus patient controls (N = 20) and normal subjects (N = 50). Specifically, we will discuss schizophrenialinked changes in reactivity, sensorimotor gating, and habituation. These data are interpreted in conjunction with clinical state ratings (BPRS, SANS, SAPS), as well as with recent animal studies using PCP, MDMA, apomorphine, amphetamine, and antipsychotic medications. Cumulatively, these studies allow us to paint a fuller picture of the neurobiological substrate of schizophrenia and attentional abnormalities in the group of schizophrenias.
157 RIGHT VISUAL FIELD DEFICITS IN REACTION TIME AFTER INVALID CUES IN CHRONIC AND NEVER-MEDICATED SCHIZOPHRENICS COMPARED TO NORMAL CONTROLS S.G. Potkin, J.M. Swanson, M. Urbanchek, D. Carreon, G. Bravo Orange, CA
Fifteen right-handed, drug-free DSM-III-R chronic schizophrenic patients (CS), eight first-break schizophrenic patients (FB), and eight normal right-handed controls (NC) were evaluated for their ability to direct visual attention in space. In the schizophrenic patients but not in NC, we found longer reaction time to targets in the right visual field (RVF) when attention was not first directed there (the invalid cue condition). This RVF increase in reaction time (RT) was observed in both the CS and the FB, drug-naive schizophrenic patients. This suggests that the RVF disadvantage is not a function of neuroleptic medication or other treatment factors since it exists in these schizophrenics prior to treatment. Further, the magnitude of the RVF increase in RT was similar in these patients, suggesting lack of progression in this lateralized component of attention. A major new finding of this study is that the FB patients had much faster RT than the CS (350 versus 500 milliseconds) and did not differ from normal controls, consistent with a progressive deterioration of the overall nonlateralized component of RT during the course of schizophrenia. This acute/chronic total RT difference is consistent with other RT studies (Nuechterlein and Dawson, 1984). These attentional abnormalities in schizophrenics have some similarities to patients with leftsided parietal lesions in which the ability to disengage from a left-sided cue to shift attention to a right-sided target is impaired. Schizophrenic patients, however, do not have a dense hemineglect and bump into objects on the right. Dysregulation in connections between the posterior and anterior attentional systems through the nucleus accumbens, striatum, pallidum, and thalamus may explain the diverse attentional deficits found in schizophrenia.
158 EYE MOVEMENT ABNORMALITIES IN SCHIZOPHRENIA John A. Sweeney, Gretchen L. Haas, Brett Clementz, Peter Weiden, Allen Frances, J. John Mann New York, IVY Eye movement dysfunctions (EMD) in schizophrenia are a promising familial marker and a potentially informative neurophysiological abnormality. Yet, basic questions about the EMD in schizophrenia remain unanswered, including the precise characterization of the oculomotor disturbance, the diagnostic specificity of the impairment,
BIOLPSYCHIATRY 1989;25:14A-79A
77A
information processing dysfunction of schizophrenic (N = 70) versus patient controls (N = 20) and normal subjects (N = 50). Specifically, we will discuss schizophrenialinked changes in reactivity, sensorimotor gating, and habituation. These data are interpreted in conjunction with clinical state ratings (BPRS, SANS, SAPS), as well as with recent animal studies using PCP, MDMA, apomorphine, amphetamine, and antipsychotic medications. Cumulatively, these studies allow us to paint a fuller picture of the neurobiological substrate of schizophrenia and attentional abnormalities in the group of schizophrenias.
157 RIGHT VISUAL FIELD DEFICITS IN REACTION TIME AFTER INVALID CUES IN CHRONIC AND NEVER-MEDICATED SCHIZOPHRENICS COMPARED TO NORMAL CONTROLS S.G. Potkin, J.M. Swanson, M. Urbanchek, D. Carreon, G. Bravo Orange, CA
Fifteen right-handed, drug-free DSM-III-R chronic schizophrenic patients (CS), eight first-break schizophrenic patients (FB), and eight normal right-handed controls (NC) were evaluated for their ability to direct visual attention in space. In the schizophrenic patients but not in NC, we found longer reaction time to targets in the right visual field (RVF) when attention was not first directed there (the invalid cue condition). This RVF increase in reaction time (RT) was observed in both the CS and the FB, drug-naive schizophrenic patients. This suggests that the RVF disadvantage is not a function of neuroleptic medication or other treatment factors since it exists in these schizophrenics prior to treatment. Further, the magnitude of the RVF increase in RT was similar in these patients, suggesting lack of progression in this lateralized component of attention. A major new finding of this study is that the FB patients had much faster RT than the CS (350 versus 500 milliseconds) and did not differ from normal controls, consistent with a progressive deterioration of the overall nonlateralized component of RT during the course of schizophrenia. This acute/chronic total RT difference is consistent with other RT studies (Nuechterlein and Dawson, 1984). These attentional abnormalities in schizophrenics have some similarities to patients with leftsided parietal lesions in which the ability to disengage from a left-sided cue to shift attention to a right-sided target is impaired. Schizophrenic patients, however, do not have a dense hemineglect and bump into objects on the right. Dysregulation in connections between the posterior and anterior attentional systems through the nucleus accumbens, striatum, pallidum, and thalamus may explain the diverse attentional deficits found in schizophrenia.
158 EYE MOVEMENT ABNORMALITIES IN SCHIZOPHRENIA John A. Sweeney, Gretchen L. Haas, Brett Clementz, Peter Weiden, Allen Frances, J. John Mann New York, IVY Eye movement dysfunctions (EMD) in schizophrenia are a promising familial marker and a potentially informative neurophysiological abnormality. Yet, basic questions about the EMD in schizophrenia remain unanswered, including the precise characterization of the oculomotor disturbance, the diagnostic specificity of the impairment,