Short-term adaptation in single auditory nerve fibers: some poststimulatory effects.

Abstract

Adaptation was produced by CF stimuli with durations ranging from 10 to 300 msec and intensities within 60 dB above a unit's threshold. The exposure caused a decrement in the response to a CF test tone applied after the termination of the adapting stimulus. In general, the poststimulatory decrement seemed to depend on the per‐stimulatory response to the adapting tone and not directly on the parameters of the adapting stimulus. For example, the decrement followed a saturating function of adapting sound intensity and was approximately proportional to the per‐stimulatory firing rate. At sufficiently high test intensities, the decrement was constant and independent of test intensity, and the saturation rate produced by the test tone was reduced. These poststimulatory results are qualitatively consistent with a model previously developed to describe some per‐stimulatory effects of short‐term adaptation [R. L. Smith and J. J. Zwislocki, Biol. Cybern. 17, 169–182 (1975)]. In both situations, a peripheral saturation appears to precede adaptation and limit the effects of high sound intensities.