Signal duration and choosing between signaled and unsignaled reward

The effects of signal duration when choosing between signaled and unsignaled response-independent reinforcers were examined in two experiments. In Experiment 1, albino rats were given a choice between signaled and unsignaled food delivered on variable-time 60-sec schedules using a 20-sec signal. All subjects preferred the signaled schedule at a level comparable to that reported in an earlier study using a 5-sec signal. Experiment 2 presented six rats with a direct choice between a 5-sec and a 20-sec signal condition, and three rats with a choice between a 1.5-sec and a 5-sec signal duration. Subjects preferred the 20-sec signal over the 5-sec signal, but no pReference was found with the 1.5-sec vs. a 5-sec signal. Current theoretical views, such as delay reduction and behavioral competition, are considered.