DIFFERENCES IN PERFORMANCE OF YOUNG AND OLD MONKEYS ON A VISUOSPATIALMEMORY TASK

Two groups of stumptailed macaques (Macaca arctoides) were compared in terms of performance on a visuospatial working memory task involving repeated presentations of an array of 15 doors, each of which conceale d one food reward at the start of a session. Rewards obtained by the s ubject were not replaced. Errors were defined as responses to doors pr eviously pushed open during the session. Both groups generally obtaine d all rewards and showed improved performance across sessions, but old monkeys consistently made more errors than young ones, especially in the latter half of a given session. Further, old monkeys were less div erse in the errors they made, indicating different response strategies by the two groups.