Abstract
Four pigeons were run in a two-choice discrete-trial situation to determine which of two principles, i.e., reinforcement of functional response unit and momentary maximizing, works in generating response patterns. After two or more responses to one key (right for 2 birds while left for the others; denoted as A) a changeover response to the other key (denoted as B) was reinforced with .30, whereas after two or more B, A was reinforced with .90. In other cases A and B were reinforced with the probabilities of .15 and .05, respectively. Results showed that birds in the present experiment made more changeover responses to B side after two or more (mostly two) As than after a single A, following which they mostly made only one B and returned to A: The birds showed responding of “AABAAB...”, “AAABAAAB...”, “AAAABAAAAB...”, and so on most of the time. This behavior is interpreted as closer to that predicted by momentary maximizing than that predicted by the functional response unit notion.
