Effects of response pacing on conditioned suppression

In this experiment, which employed a balanced design with two rat subjects, the frequency of reinforcement remained constant while the rate of operant responding was varied by means of a response pacing technique. At each of three response rates, 1-min. periods of noise were presented, and, as these periods ended, a slight unavoidable shock was delivered to the rat. This procedure resulted in suppression of the operant responding during the periods of noise. This behavioural change was measured by a suppression ratio, essentially a comparison of the response rates in the presence and absence of the noise. The suppression ratios varied in a systematic way during the experiment, denoting most conditioned suppression when the baseline rate of responding was high, and least suppression when this was low. It is therefore concluded that response rate in one factor determining the degree of conditioned suppression in this controlled experiment. The conclusion is corroborated by absolute measures of responding during the pre-shock periods of noise.