Inhibitory control of attention declines more than working memory during normal aging.

Changes in frontostriatal systems are believed to reduce the efficiency of executive cognitive functions during normal aging, especially the inhibitory control of attentional and behavioral responses. To characterize changes during normal aging in sensorimotor, working memory and inhibitory attentional systems, we tested 20 healthy elderly subjects (age 65-80) and 28 young adults (age 18-34) using oculomotor paradigms. Visually guided saccades of elderly subjects showed decreased peak velocity and increased reaction time, but not reduced accuracy, indicating selective age-related declines in sensorimotor systems. In an oculomotor working memory task, memory for spatial location information in elderly subjects was as accurate as in young adults. In contrast, elderly subjects demonstrated a significantly reduced ability to voluntarily inhibit eye movements toward flashed targets on an antisaccade task. These findings indicate changes in frontostriatal systems during normal aging that adversely affect volitional inhibitory processes but spare encoding and retrieval components of spatial working memory.