Increase and Decrease in Light and Noise Stimuli as Reinforcers for Albino Rats

Abstract

The effect upon response latencies of random increases or decreases in stimulus intensity following a barrier-crossing response in a Mowrer-Miller shuttle box was studied. Stimulus change was contingent upon the response. 32 albino rats were randomly assigned to a control group which received no stimulation and to three experimental groups: Group L (subjected to changes in light), Group N (subjected to changes in noise), and Group LN (subjected to changes in light and noise). It was found that (a) in terms of mean latencies Group LN differed significantly from Group L and the control group. (b) Although the trial effect was significant, response latency did not consistently decrease over trials. (c) The mean number of spontaneous crossings was significantly larger for Group LN than for all other groups. (d) The mean number of spontaneous crossings increased over trials.