Concurrent and predictive electrodermal correlates of symptomatology in recent-onset schizophrenic patients.

Electrodermal activity and symptomatology were interrelated in a group of 56 male and 13 female recent-onset schizophrenic patients. Electrodermal activity was indexed by the frequency of nonspecific skin conductance responses and the number of trials to habituation of the skin conductance orienting response. Symptomatology was assessed by the Brief Psychiatric Rating Scale (BPRS) on 2 separate test occasions. The 1st test occasion was during the inpatient period when psychotic symptoms were prevalent and medications were variable. The 2nd test occasion was several mo later during an outpatient period when symptoms were stabilized and medications held constant. Electrodermal activity was positively and significantly related to a number of symptoms in male patients, most reliably the BPRS factors Activation and Hostility/Suspiciousness. These relationships were most consistent during the outpatient period. Of particular theoretical interest, greater electrodermal activity during the inpatient period was associated with greater outpatient psychopathology. The results suggest that heightened inpatient electrodermal activity is predictive of poor short-term symptomatic recovery in recent-onset, acute, male schizophrenic patients. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Selective corticostriatal dysfunction in schizophrenia: Examination of motor and cognitive skill learning.

[Correction Notice: An erratum for this article was reported in Vol 22(3) of Neuropsychology (see record 2008-05020-015). Table 1 on page 102 should have included the BPRS Depression-Anxiety subscale score 9.00 (3.99) under the column heading Schiz pts. Table displays means with standard deviations in parentheses.] [Correction Notice: An erratum for this article was reported in Vol 22(2) of Neuropsychology (see record 2008-02526-002). The DOI for the supplemental materials was printed incorrectly. The correct DOI is as follows: http://dx.doi.org/10.1037/0894-4105.22.1.100.supp.] It has been suggested that patients with schizophrenia have corticostriatal circuit dysfunction (Carlsson & Carlsson, 1990). Skill learning is thought to rely on corticostriatal circuitry and different types of skill learning may be related to separable corticostriatal loops (Grafton, Hazeltine, & Ivry, 1995; Poldrack, Prabhakaran, Seger, & Gabrieli, 1999). The authors examined motor (Serial Reaction Time task, SRT) and cognitive (Probabilistic Classification task, PCT) skill learning in patients with schizophrenia and normal controls. Development of automaticity was examined, using a dual task paradigm, across three training sessions. Patients with schizophrenia were impaired at learning on the PCT compared to controls. Performance gains of controls occurred within the first session, whereas patients only improved gradually and never reached the performance level of controls. In contrast, patients were not impaired at learning on the SRT relative to controls, suggesting that patients with schizophrenia may have dysfunction in a specific corticostriatal subcircuit. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Autonomic orienting and the allocation of processing resources in schizophrenia patients and putatively at-risk individuals.

The differential allocation of attentional resources to attended and ignored stimuli was examined by measuring skin conductance orienting responses and secondary reaction time in relatively asymptomatic schizophrenia outpatients, demographically matched normal controls, college students putatively at risk for psychosis, and a college student control group. At-risk participants were those with extreme scores on scales for either anhedonia or perceptual aberration-magical ideation (per-mags). Compared to control groups, the patients and per-mags showed secondary reaction time results suggesting a delay in the differential allocation of attentional resources. This deficit was observed particularly in patients and matched controls with few or no skin conductance orienting responses, suggesting that impaired autonomic orienting is related to underlying cognitive-attentional vulnerability factors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Does anhedonia in schizophrenia reflect faulty memory for subjectively experienced emotions?

The authors evaluated whether self-reported trait anhedonia in schizophrenia reflects faulty memory, such that patients are capable of experiencing pleasure while engaged in enjoyable activities but underestimate their pleasure in recalling these experiences. Thirty schizophrenia patients and 31 nonpatient control participants rated their emotional responses to pleasant and neutral foods and film clips and completed a surprise recall task for their emotions after a 4-hr delay. Despite reporting elevated trait anhedonia, patients did not significantly differ from control participants in immediate pleasant emotional responses to the stimuli or in delayed recall for these experiences. In-the-moment pleasure and short-term retention for emotional experiences thus appear to be relatively intact in schizophrenia. Alternative explanations for the hedonic deficit in this disorder are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reduced regional brain glucose metabolism assessed by positron emission tomography in electrodermal nonresponder schizophrenics: A pilot study.

Examined whether electrodermal nonresponder and responder subgroups of schizophrenic patients differ in regional brain metabolism assessed by positron emission tomography during a continuous performance test. In comparison to both 6 normal controls and 3 responder schizophrenics, the 3 nonresponder schizophrenics showed about a 20% reduction in metabolic rate across the entire brain. Nonresponder schizophrenics tended to have lower absolute metabolic rates than responders in lateral and medial frontal, thalamic, and hippocampal areas. Nonresponders also had significantly lower relative metabolic rates in medial frontal and hippocampal areas as well as the right amygdala. These data suggest that electrodermal subgroups of schizophrenics differ in both regionally specific brain metabolic processes thought to be involved in electrodermal activity and in generalized brain metabolism. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Electrodermal activity as a prodromal sign in schizophrenia

To simplify the quality control procedure used to determine the efficiency and consistency of bedside leukoreduction, a counting protocol using prefiltration and postfiltration aliquots fixed in 10% formaldehyde was designed. To assess the reliability of the values obtained by counting the formalin-fixed samples, a parallel study was performed using our standard protocol of counting fresh propidium iodide-stained samples in a Nageotte chamber under a fluorescent microscope. A total of 30 single-donor platelet concentrates and 30 units of packed red blood cells were analyzed in parallel using the standard and formalin-fixation methods. Furthermore, the aliquots fixed in formaldehyde were split and counted at 1, 3, and 30 days. The results showed no significant quantitative difference between the two methods. Of note is that the counts in formaldehyde-fixed samples at 1, 3, and 30 days were consistent among themselves. The formaldehyde fixation of samples obtained for quality control of leukoreduction allows blood collection and storage at 4 degrees C and batch counting when and where convenient.     

Communication deviance in families of schizophrenic and manic patients.

Levels of communication deviance (CD) distinguish parents of schizophrenic patients from parents of nonpsychotic patients, but the prevalence of intrafamilial CD in other psychotic disorders has not been examined. Levels of CD were compared across biological parents of schizophrenic (n?=?39) and bipolar manic (n?=?16) patients and across patients themselves. CD ratings were based on Thematic Apperception Test (TAT) protocols (parents only) and family interactions (parents and patients). Total levels of CD did not distinguish between groups of parents or patients. However, instances of odd word usage were more frequent among parents of manic patients than among parents of schizophrenic patients on both CD measures. Also, during the interaction task, odd word usage was more frequent among manic patients, whereas schizophrenic patients made more ambiguous references. Results suggest that high levels of intrafamilial CD are not unique to schizophrenia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)