Habituation and dishabituation of the averaged auditory evoked response.

Abstract

Two experiments investigated amplitude reduction in the averaged evoked response (AER) resulting from repeated auditory stimulation. The first experiment examined the effects of stimulus duration on the rate of AER habituation. Three groups of 10 normal-hearing young adults received 16 series of 1000-Hz tone bursts with durations of 50 msec, 500 msec, and 950 msec. A comparison of AER habituation rates revealed that longer stimulus durations resulted in faster rates of habituation. The second experiment was designed to determine if the AER demonstrated dishabituation (recovery of a habituated response when a parameter of the habituating stimulus is changed). Ten additional normal adults received series of 1000-Hz tone bursts. When the stimulus frequency was changed from 1000 Hz to 500 Hz, all subjects meeting the habituation criterion demonstrated recovery of the AER. The results of the two experiments are compatible with an interpretation of AER habituation as a simple form of learning.