Lifelong physical activity and executive functions in older age assessed by memory based task switching.

Aging is accompanied by compromised executive control. Training studies point to beneficial effects of physical activity on executive functions. Here, we investigate the relationship between lifelong habitual physical activity (about 50 years) and switch ability in healthy seniors. Participants switched among three tasks in a memorized task sequence. Mixing costs for speed were lower in habitually active than low active participants whereas switch costs were not affected. Active participants revealed also lower mixing and switch costs for accuracy. These parameters were negatively correlated with the self-reported level of physical activity. The frontal CNV was smaller in the active than low active group. In contrast, in the target-locked ERPs active individuals showed an earlier P2, a larger frontocentral N2 and the typical pattern of smaller P3b in switch than non-switch trials relative to low-active individuals. These data suggest that lifelong physical activity is associated with faster recall of stimulus-response sets (P2), enhanced response selection during interference processing (N2) and working memory updating (P3b) leading to lower mixing and switch costs.