This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Human studies suggest that changes in motor function may accompany or predict cognitive decline and onset of dementia. Therefore monitoring of motor function may provide an early sign of incipient cognitive impairment. However, relationships among motor and cognitive function during aging are not well understood, and it is not clear which measures of motor function are best correlated or predictive of cognitive status. Furthermore, disruption of sleep and circadian rhythms is common in the elderly and may contribute to, or correlate with, both motor and cognitive impairment. Nonhuman primates provide an excellent model for testing these relationships as they have cognitive abilities most similar to humans and show similar trajectories of motor and cognitive decline with age. We have available a cohort of aging female rhesus monkeys that have been trained to perform several assessments of cognitive function and have generated longitudinal data as part of a study of ovariectomy and hormone replacement. They represent an extremely valuable resource that now can be used to address the relationships among measures of 1) different cognitive abilities, including spatial working memory and recognition memory, 2) motor function, including locomotion, fine motor skills, simple reaction time and 3) circadian activity and sleep fragmentation. We will also compare measures of activity, locomotion and motor function obtained with different technologies. The data are of immediate relevance to clinical researchers planning related human studies, and will provide the basis for future studies aimed at elucidating underlying neural mechanisms of aging and developing treatment strategies.