Brief Stimuli Paired with Food: Comparison of Two Schedule Arrangements

Abstract

Pecks by pigeons produced food according to a fixed-interval schedule. Pecks also produced a brief blackout according to a small fixed-ratio schedule. Each food delivery was immediately preceded by a brief blackout, but not all blackouts were followed by food. The schedule of food and the schedule of blackouts were combined two ways. On one, a second-order schedule, each fixed-ratio completed during the fixed-interval produced the blackout. The first fixed-ratio completed after the fixed-interval elapsed produced the blackout-food compound. The second, a conjoint schedule, was identical except that the first peck after the fixed-interval elapsed produced the blackout-food compound regardless of the number of responses since the last blackout. Although the blackout was paired with food and was produced on a small fixed-ratio schedule under both arrangements, there was evidence of fixed-ratio-like response patterns only on the second-order schedule.