Spatial constraints and regulatory functions in monkeys' (Cebus apella) search

By means of an apparatus featuring a set of suspended baited containers, se arch abilities of 4 capuchin monkeys (Cebus apella) were evaluated. The exp eriment featured different spatial configurations of the search space. Resu lts showed that monkeys exhaustively searched 9 containers spatially distri buted as a 3 x 3 matrix, a cross, a line, or a circle. Search efficiency wa s higher when the search space featured either a linear or circular arrange ment of containers. When faced with a linear arrangement of containers, the subjects developed principled search trajectories from 1 end to the other of the linear array. This behavioral regulation was independent from search efficiency as measured by the amount of visits to containers already explo red. The data suggest that monkeys use either the travel distance or the co gnitive costs associated with unprincipled travel trajectories as currency for regulation.