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Numerous types of age-related deficits in the nervous system have been well documented. While a distinction between general types of memories that are susceptible to compromise with advanced age has been fairly well agreed upon, it is often difficult to determine exactly which specific processes are detrimentally influenced. In this study, we used a paradigm that enabled us to distinguish between effects associated with gross motor deficits and those due to learning and memory of a motor skill, per se. In terms of both latency and errors, senescent animals were, on average, impaired in their ability to traverse an elevated obstacle course, compared to younger animals. Yet, if gross motor abilities are accounted for, a fraction of these deficits is readily explained. Moreover, if individual baseline performance differences are normalized, no memory differences are evident across age groups. These observations suggest that memory for a procedural task is not impaired with advanced age.

While limited research is available, evidence indicates that physical and mental activity influence the aging process. Human data show that executive functions of the type associated with frontal lobe and hippocampal regions of the brain may be selectively maintained or enhanced in humans with higher levels of fitness. Similarly enhanced performance is observed in aged animals exposed to elevated physical and mental demand and it appears that the vascular component of the brain response may be driven by physical activity whereas the neuronal component may reflect learning. Recent results have implicated neurogenesis, at least in the hippocampus, as a component of the brain response to exercise, with learning enhancing survival of these neurons. Non-neuronal tissues also respond to experience in the mature brain, indicating that the brain reflects both its recent and its longer history of experience. Preliminary measures of brain function hold promise of increased interaction between human and animal researchers and a better understanding of the substrates of experience effects on behavioral performance in aging., (Copyright 2002 Elsevier Science Inc.)