Psychophysiological Dysfunctions in the Developmental Course of Schizophrenic Disorders

Abstract

Psychophysiological anomalies in symptomatic schizophrenic patients, remitted schizophrenic patients, and individuals at heightened risk for a schizophrenic disorder are reviewed with an emphasis on electrodermal anomalies. Two electrodermal anomalies are identified in different subgroups of symptomatic patients: (1) an abnormally high sympathetic arousal and (2) an abnormal absence of skin conductance orienting responses to innocuous environmental stimuli. The same two electrodermal anomalies also have been observed in remitted schizophrenic patients. Among high-risk individuals, the offspring of schizophrenic patients display abnormally high electrodermal responsiveness to aversive stimulation, whereas a substantial proportion of college students who score high on physical anhedonia (a putative risk factor for schizophrenia) exhibit skin conductance nonresponsiveness. Thus, heightened sensitivity to aversive stimulation appears to be associated with a genetic vulnerability to schizophrenia, while tonic hyperarousal , which occurs in subgroups of symptomatic and remitted schizophrenic patients, may reflect a later developmental consequence of the underlying vulnerability. Skin conductance nonresponsivity may represent a different developmental consequence associated with the same underlying vulnerability or it may represent a different type of vulnerability. Other psychophysiological anomalies also are promising indicators of the vulnerability to schizophrenia (e.g., deviant smooth pursuit eye movements, attenuated P300 component of the event-related brain potential, reduced electroencephalic (EEG) alpha activity, and heightened EEG delta activity).

Positive and Negative Symptoms in Schizophrenia: Attentional Performance Correlates

“…Gjerde proceeds to sug gest that hyperarousal produces a deficit in the control function that governs the mobili zation and allocation of attention. A recent review of psychophysiological research on schizophrenia [10] concludes that hyper arousal does indeed characterize a subgroup of schizophrenic patients, and that this sub group shows more positive symptoms [7,15,32], and greater deficits in selective attention to target stimuli [28]. Thus, findings from the psychophysiological research, in combi nation with Gjerde's model, provide an in terpretive base for the present results.…”

Stress-Induced Dopamine Release in Humans at Risk of Psychosis: a [11C]Raclopride PET Study

“…Elevated PhysAn scores in the adolescent offspring of schizophrenic patients are associated with increased rates of psychosis and poorer social adjustment in young adulthood (Erlenmeyer-Kimling et al, 1993;Freedman et al, 1998). Healthy individuals with elevated scores on the PhysAn scale also show many attributes of a high-risk population: they have an increased incidence of the cognitive, behavioral, and social abnormalities associated with schizophrenia, including impaired attention (Jutai, 1989;Wilkins and Venables, 1992;Erlenmeyer-Kimling et al, 1993), reaction time crossover (Simons, 1982), abnormal P300 amplitude (Miller, 1986), skin conductance nonresponsiveness (Dawson and Nuechterlein, 1984), and poorer social competence (Garnet et al, 1993;Blanchard et al, 1998). Further, PhysAn scores may have a familial component as they are higher in schizophrenic patients and their relatives than controls (Katsanis et al, 1990;Clementz et al, 1991;Franke et al, 1993), and are higher in individuals with schizophrenia-related personality disorders who have a genetic loading of schizophrenia than in those without it (Thaker, 2000).…”

Neuroendocrine Responses to a Cold Pressor Stimulus in Polydipsic Hyponatremic and in Matched Schizophrenic Patients

“…In fact, schizophrenic patients are often quite adept at simply ignoring psychological stimuli (Dawson and Nuechterlein, 1984;Jansen et al, 2000;Zahn and Pickar, 2005). Psychological stressors are stimuli that signal, but do not in themselves constitute, a potential threat to homeostasis.…”