ATTENTION TO COMPETING VOICE MESSAGES BY NONACUTE SCHIZOPHRENIC PATIENTS

Abstract

The ability of nonacute, nonchronic schizophrenic patients to attend to 1 of different numbers of competing voice messages was examined under the influence of 2 tranquilizer and 2 stimulant drugs each at 3 or 4 dosage levels. Intelligibility scores of 71 patients were analyzed. No significant drug effects could be detected. There was, in general, a decrease in intelligibility scores with each increase in the number of competing voices that were presented. A comparison of the scores of subjects in this study with the scores of subjects in similar previous studies revealed increasingly impaired performance in the following order: normal subjects, nonacute, chronic and acute schizophrenic patients. The results are considered to represent deficits in attention due not only to shifts in attention from relevant to irrelevant stimuli but to periodic defocusing or upward shifts in sensory threshold which do not permit the individual to detect, process and become aware of stimuli impinging on his central nervous system at the same rate displayed by normal individuals. Diagnosis, psychopathology, age, sex, number of hospitalizations, intelligence and anxiety were not associated with significant differences in intelligibility scores. The primary factors associated with significant deficits in auditory information processing performance were acuteness of illness, length of hospitaliza-tion and history of ECT [electroconvulsive therapy]. Patients who had received ECT performed significantly worse than those who had not. The possibility that this represents subtle organic central nervous system damage is discussed.