Spontaneous fluctuations of electrical skin conductance and the actual clinical state in schizophrenics.

The present paper examines in a group of 48 schizophrenics, whether spontaneous fluctuations (SF) in electrical skin conductance show a relationship to psychiatric symptomatology. Subjects participated in an experiment that delivered nonsignal auditory stimuli. Their clinical state was assessed by the Brief Psychiatric Rating Scale (BPRS) and the Nurses' Observation Scale for Inpatient Evaluation (NOSIE). An additional set of factors with a possible influence on SF rates was also taken into account. A stepwise regression analysis showed BPRS Activation and NOSIE Manifest Psychosis to be of significance, the BPRS subscale displaying a positive and the NOSIE subtest a negative partial correlation to SF frequency. Results are discussed with regard to their implication for experiments using tonic electrodermal measurement; they are also compared with the literature on phasic electrodermal arousal.