SOCIAL FORAGING IN RATS: GROUP AND INDIVIDUAL CHOICE IN DYNAMIC ENVIRONMENTS

Abstract

Group and individual choice behavior in dynamic social environments was examined in a laboratory foraging analogue. Five rats were studied across multiple sessions in a free-ranging paradigm, where food reinforcement was delivered from two patches according to variable time intervals. Five reinforcement ratios (1:1, 1:4, 1:8, 8:1, 4:1) were presented either in irregular sequence within a session (Variable condition) or across sessions (Stable). Competitiveness, defined in terms of obtained resources, was assessed by delivering food at one feeder only. The generalized matching law and ideal free distribution accounted for individual and group data well. Sensitivity of the group and individual behavior to reinforcement contingencies increased with less variability in resource availability, but also increased with greater experience. The experimental paradigm shows great promise for examining adaptive behavior in a social context.