Absolute auditory threshold and threshold of unpleasantness of chronic schizophrenic patients and normal controls.

Abstract

The method of average error was modified tor research in schizophrenia and was used in establishing both the absolute auditory threshold and the threshold of unpleasantness. The results showed chronic schizophrenic patients had a higher absolute threshold but a lower threshold for when a tone became unpleasantly loud. The results add evidence that chronic schizophrenic patients find external stimulation aversive; they point out the narrow range of auditory stimuli in which schizophrenics function; and suggest that the same auditory stimuli cannot be considered equivalent for schizophrenic patients and normal controls. The results of a stimulus-seeking experiment showed that chronic, nonparanoid schizophrenic patients preferred a noise stimulus of varying intensity to be off, while normal controls preferred it on (Levine, 1967). These results were interpreted as indicating a motivational process in which schizophrenic patients avoid external stimulation simply because external stimulation is unpleasant to them. However, another explanation for the findings is that schizophrenic patients have greater auditory sensitivity than normals. If patients were more sensitive, then the stimuli used would not be perceptually equivalent and would tend to be differentially aversive. The patients would then be expected to show the obtained results of preferring the noise off. Previous research in schizophrenic audition