Memory systems in normal and pathological aging.

Normal memory depends on a number of interdependent systems whose specialized contributions are dissociable at both cognitive and neurobiological levels of analysis. Guided by this multiple systems view of memory, this review provides a selective survey of recent studies on cognitive and neurobiological aging. Taken together, the results suggest that memory decline in human aging partly reflects a compromise of executive memory processes supported by frontal lobe regions of the brain, combined with a deterioration of explicit memory capacities supported by the hippocampal system. Defining how deficits in multiple memory systems interact to account for cognitive aging remains a significant challenge.