Overview of models of cognitive aging

This chapter reviews major theories of cognitive aging. Theories such as the sensory deficit hypothesis, speed of processing, and inhibitory deficit hypothesis are based largely on behavioral findings and focus on a single process that is purported to account for a number of cognitive changes with age. Specific to memory, theories focus on age deficits in recollection and binding. Over the past twenty-five years, brain-based models have begun to pervade the literature. These have focused on concepts such as compensation, dedifferentiation, and suppression of the default mode network. The scaffolding theory of aging and cognition integrates many of these concepts into a single comprehensive model, including consideration of enrichment and depletion factors that operate over the life span. We conclude the chapter with some debates, critiques, and consideration of future directions, particularly considering the contributions of cognitive neuroscience methods.