RECOGNITION MEMORY SPAN IN RHESUS-MONKEYS OF ADVANCED AGE

Assessment of recognition memory was performed on eight rhesus monkeys of advanced age (25 to 27 years of age) using the delayed recognition span test (DRST). Their performance was compared to that of five youn g adult animals (5 to 7 years of age) on two stimulus conditions of th e DRST: spatial position and color. Both trial unique and repeating se ries were used for each of the two conditions. As a group, aged monkey s were impaired on both the spatial and color conditions of the DRST, achieving about two-thirds of the span of the young adult group in eac h condition. Error analyses revealed that monkeys in the aged group al so produced more perseverative responses (i.e., displacing the previou sly correct disk) than did young adults. Together the findings suggest that monkeys of advanced age are impaired on tasks with memory loadin g demand characteristics. Copyright (C) 1996 Elsevier Science Inc.