No abstract

Two experiments investigated the effects of intertrial nonreinforcement (lTN) in a discrete-trials instrumental escape conditioning paradigm. In Experiment 1 an ITN group was more resistant to extinction than a continuously reinforced group but less resistant than a partially reinforced group. This ITN effect was replicated in Experiment 2. The performance of an additional control group in Experiment 2 suggests that this effect, in the present escape learning paradigm, may be due to a stimulus generalization decrement mechanism rather than to the operation of sequential variables.