The Success Rate in a Complicated Spatial Memory Test Is Determined by Age, Sex, Life History and Search Strategies in Cynomolgus MonkeysAuthor: Huda S. Darusman, Otto Kalliokoski, Dondin Sajuthi, Steven J. Schapiro, Albert Gjedde, and Jann Hau
In a retrospective analysis of data from three studies using a delayed response task in cynomolgus monkeys, we examined the subjects’ search patterns and success rates. Twenty-seven monkeys of both sexes, divided into three age groups, were tasked with retrieving two food items hidden in an array of six identical opaque cups. Although the task was challenging for all subjects, generating a high level of guesswork, evidence of common behaviors when approaching the spatial memory test were found. The search patterns employed by the monkeys suggest the use of landmark cues, adaption in response to failure and chronological memory recall. These strategies appeared to be shared by most subjects, however, the overall success rate appeared to also depend on individual characteristics including age, gender and whether the subject had been born in caged captivity or not. By elucidating some of the underlying cognitive mechanisms, these findings may serve to refine interpretation of future studies using similar delayed response tasks in non-human primates.
Key Words: Primate, memory recall, age-associated memory impairment, breeding