Organized responding in instrumental learning: Chunks and superchunks

Abstract

Two investigations attempted to determine if rats could learn that the second series of runway trials, the test series, was the same as the first series, the study series. Series were constructed from runway responses which terminated either in food reward (R) or nonreward (N). In the series RNR, for example, three successive responses terminated in R, N, and R, respectively. Rats manifested mastery of a series by running fast to R and slow to N. In Experiment 1 the test series (either RNR or RNN) occurred in a black runway about 15 s after the study series presented in a white runway. In Experiment 2 the test series (either RN or RRN) occurred in a gray runway about 15 min after the study series, also in a gray runway. In both experiments rats learned that the study series was the same as the test series. A hierarchical interpretation was suggested in which runway trials are organized into series, series being organized into lists.