Cue-producing behavior in the Capuchin monkey during reversal, extinction, acquisition, and overtraining.

In a two-choice discrimination situation, a cue-producing response produced the discriminanda for 0.05 sec. The cue-producing responses beyond those normally necessary to identify the discriminanda thus provided only redundant information. Two of the four Capuchin monkeys studied showed a large increase in cue-producing responses during reversal learning and extinction, and they reversed much faster than the two whose cue-producing responses showed little increase. During acquisition of a difficult discrimination, the cue-producing responses of the first two subjects reached a high level and during overtraining gradually reduced to their initial low level. The results were related to Wyckoff's theory of observing behavior and to the notions of uncertainty, reduction, and lack of information as extensions of the concepts of reinforcement and motivation.