Habituation and rehabituation of the monkey–s orienting reflex as a function of stimulus variability

Abstract

Fourteen Cebus albifrons monkeys were divided into two groups, one receiving an unchanging pure tone and the other a pure tone that varied in frequency from trial to trial. Following habituation of the skin conductance response, both groups were switched to a new tone for rehabituation. The monkeys needed significantly fewer trials to reach rehabituation than were needed in habituation, but the groups did not differ in this respect. Response magnitudes and reciprocals of response latency reduced significantly from habituation to rehabituation, but these effects also did not differ between groups. The group that received an unchanging pure tone showed significant reduction in response magnitude from the first to the second trials of habituation and rehabituation, but this reduction did not occur in the group that received frequency variability. It was concluded that the monkey’s skin conductance response to pure tones habituates in a manner similar to that of the human, but that the retardation of habituation produced by stimulus variability in humans was not as strongly manifested in the monkey. © 1979, Psychonomic Society, Inc.. All rights reserved.