A theory of cognitive control, aging cognition, and neuromodulation.

A theory is described which links cognitive changes observed in normal aging to an underlying decline in the function of the dopamine (DA) system projection to prefrontal cortex (PFC). The theory postulates that this neural mechanism is integral to the representation, maintenance and updating of context information, and as such impacts cognitive control across a wide range of cognitive domains, including working memory, attention, and inhibition. Behavioral and brain imaging data in support of the theory are discussed, which demonstrate selective impairments in context processing among healthy older adults associated with abnormal PFC activation. These findings highlight the utility of a computational approach to cognitive aging. Current directions for further refinement and validation of the model are outlined.