Escape from the peak procedure

Abstract

The peak procedure is a timing procedure used to measure the ability of animals to time intervals. The peak procedure consists of fixed interval (FI) trials and some non-reinforced or extinction trials (EXT). Typically, responding on EXT trial increases at the usual time of reinforcement on the FI trial then decreases and resurges towards the end of the EXT trial. One short-coming of the peak procedure is that there is only one response alternative available to the animal, which might explain why, even after extensive experience, the animals still respond at high rates at times when they would never earn food reinforcers. In my experiment, I hypothesised that the reason response rates increase towards the end of EXT trials on the peak procedure is because those responses are negatively reinforced by escaping the EXT trials and resurgence maybe the result of escape from the EXT trials. This “escape” hypothesis was tested in different conditions. Results show roosters have a sense of time and by providing an alternative key to response; the birds’ performance on the peak procedure was improved.