Neuroimaging of Healthy Cognitive Aging

Cognitive aging research and theory has, until recently, been based upon behavioral measures of cognitive performance such as response time and accuracy. Results from behavioral methodologies have indicated a general age-related decline in cognitive functions such as speed of processing, attention, perception, working memory, and cued and free recall—and age invariance when assessing cognitive processes associated with vocabulary and semantic memory. Recently, advances in the area of neuroimaging have allowed for the examination of the relationship between cognitive and neural differences in the aging brain. Given that cognitive processes depend on brain anatomy and physiology, it is natural to expect that previously observed behavioral differences in aging are intimately linked to age-related changes in the integrity of cerebral architecture and function. By using in vivo neuroimaging techniques such as positron emission tomography (PET) and magnetic resonance imaging (MRI), researchers can tap into the neural substrates of cognitive aging linking behavior and function. As this technology has improved over the last two decades, significant advances have been made in the field of functional neuroimaging of cognitive aging. Research has shown us that, despite a common notion that everything declines in aging, neural activity associated with cognitive aging is characterized by both age-related increases as well as age-related decreases in brain activity. Failure on the part of older adults to activate brain regions typically recruited by younger adults during cognitive tasks is usually characterized as neurocognitive decline. However,