Resistance To Extinction vs. Resistance to Reinforcement to Measure Inhibition

Abstract

These experiments compare resistance to reinforcement and resistance to extinction techniques for measuring inhibitory stimulus control by S — following discrimination training. In Experiment 1, rats received 24 sessions of training on a discrimination between two lights and then the inhibitory properties of S — were measured with either the resistance to reinforcement or resistance to extinction technique. Acquisition or extinction of responding to the former S — was compared to that to a novel stimulus. As expected, the resistance to extinction technique indicated more inhibition and the size of the difference increased throughout three sessions of testing. In Experiment 2, rats received 15 or 30 days of training on the discrimination problem and then all of the rats received combined-cues tests of the inhibitory properties of S —. Following 2 days of additional discrimination training, the rats were assigned to resistance to reinforcement or resistance to extinction test conditions. Resistance to extinction again indicated more inhibition than resistance to reinforcement at both levels of training, and combined-cue testing indicated the highest levels of inhibition. At the lower level of training, resistance to reinforce-ment gave no evidence of any inhibition. These data were interpreted as showing that the resistance to reinforcement technique is relatively insen-sitive, particularly to low levels of inhibition. This finding is consistent with the notion that discrimination training renders S — more condition-able as well as inhibitory.