AVERSIVE PROPERTIES OF AUDITORY-STIMULI

Three experiments examined the influence of auditory stimuli on the performance of hungry rats in an instrumental discrimination task. In Experiment 1, presenting a response-contingent auditory stimulus on an incorrect manipulandum tended to improve discrimination, relative to a group lacking a stimulus. In contrast, presenting a visual stimulus on the incorrect lever enhanced discrimination. In Experiment 2, the intensity of the auditory stimulus was varied, and the discrimination between the levers improved as the intensity of the auditory stimulus presented on the incorrect lever increased. In Experiment 3, the effect on discrimination of presenting an auditory cue on the incorrect lever was replicated, and it was also noted that the cue was capable of improving performance if it followed responses to the reinforced lever. These results imply that, in the absence of pairing with a primary reinforcer, some putatively neutral auditory stimuli possess aversive properties. (C) 1995 Academic Press, Inc.