Cognitive and neural plasticity in old age: A systematic review of evidence from executive functions cognitive training.

Cognitive training is a popular intervention aimed at attenuating age-related cognitive decline, however, the effects of this intervention on brain structure and function have not been thoroughly explored. Core executive functions (working memory, inhibition, cognitive flexibility) are dependent upon prefrontal brain regions-one of the most vulnerable areas of age-related decline. They are also implicated in numerous cognitive processes and higher-order functions. Training executive functions should therefore promote cognitive and neural enhancements in old age. This systematic review examined the effects of executive functions training on brain and cognition amongst healthy older adults across 20 studies. Behavioral performance consistently improved on trained cognitive tasks, though mixed findings were reported for untrained tasks. Training-related structural changes were reported, evidenced through increases in grey matter and cortical volume. Functional changes were not consistent, though a general pattern of increased subcortical and decreased frontal and parietal activation emerged across studies, indicating that training may potentially reduce reliance on compensatory neural mechanisms. Training executive functions appears to promote cognitive and neural plasticity in old age, though further research is required to develop a more comprehensive framework which connects and elucidates the mechanisms underlying cognitive training, cognitive transfer, and cognitive aging.