An analysis of the skin conductance orienting response in samples of American, British, and German schizophrenics.

The existing literature dealing with the phasic orienting response (OR) in schizophrenia, examining, for the most part, the skin conductance component (SCOR), reports conflicting results with divergent implications for the nature of the attentional dysfunction in these patients. The present authors have contributed to that literature and to its divergencies. The present report addresses this issue by applying a common set of response definitions and uniform statistical-analytic procedures to the previously gathered electrodermal data obtained independently in each author's laboratory. A total of 14 studies is involved, drawn from six laboratories in the U.S.A., the U.K., and West Germany. Collectively, these studies examine chronic and acute schizophrenics, males and females, those receiving neuroleptic drugs and those not receiving them, recording SCOR from either (or both) hands using a variety of instruments and somewhat differing instructions and conditions, to both auditory and visual stimuli of different intensities and rise-time properties. The authors' purpose is two-fold. First, to determine whether some 'universal' dysfunction can be demonstrated across laboratories, conditions, and samples. Given the heterogeneous origins of these data such a finding would offer fairly strong evidence of 'real' dysfunction in schizophrenia. Second, where disagreement exists, to describe the scope and nature of the disagreement, and to articulate more clearly the findings on each side of a disputed area. One such 'universal' dysfunction emerged. Consistently, schizophrenics displayed an abnormally high incidence of nonresponsiveness, involving nearly 50% of the schizophrenic sample on average. The next most common finding is that many of the schizophrenics who display an SCOR often habituate faster than do nonschizophrenic responders. This was seen in a majority of the studies and laboratories, but conflicting evidence was presented by a minority. Evidence for a dysfunction simultaneously involving SCOR hypo- and hyper-responsiveness within schizophrenia was obtained, but in a minority of studies. The possible effects of neuroleptic drugs, stimulus intensity and rise-time factors, and differential significance evaluation on these findings was discussed. The possibility that schizophrenic dysfunction involves the input-facilitating OR but not input-attenuating 'protective' responses is examined. The correlates of hyporesponsiveness in schizophrenia, including physiological response patterns, clinical symptom patterns, and specific input deficiencies, is also examined. Several areas are noted where systematic research has only begun, and further study is particularly needed.