Effects of Drive Level on the Degree of Cue Control by Squirrel Monkeys

Abstract

24 adult Squirrel monkeys (Saimiri sciureus) were presented with a discrimination task involving redundant relevant cues of size (large vs small) and form (triangle vs circle) while under high or low food deprivation. Using a modified Y-maze, all subjects were presented with 25 reinforced training trials per day until a criterion of 80% correct responding for two successive days was met. During three days of testing, responses to test simuli differing on one or both relevant training cues were interpreted as reflecting the degree of control gained by each positive cue during training. Both relevant cues gained significantly more control over behavior in the low-drive group than in the high-drive group. Since the drive groups did not differ significantly on a number of training factors, theories which have suggested an interaction of drive level and learning were supported.