Abstract
Plasticity is a concept of major importance in understanding the process of cognitive aging. Differences among individuals in neuroplasticity play an important role in accounting for different trajectories of cognitive change over time. In the present paper, we define neuroplasticity as the ability to change brain and behavior and discuss cognitive training and cognitive engagement as mechanisms of change in the context of The Scaffolding Theory of Aging and Cognition (STAC). We review evidence for structural and functional plasticity in older adults as a function of different intervention strategies. We suggest that plasticity, particularly as expressed in changes in functional activation or connectivity, can provide a mechanism to remediate the effects of cognitive decline. While evidence that cognition can be preserved or even improved in later life by leveraging residual plasticity is growing, the field has far from a complete understanding of the mechanisms of plasticity and the factors which facilitate its expression, especially in later life.