11 - Inhibitory processes in cognition and aging

Abstract

This chapter reviews a number of studies that have implications for the inhibitory decline hypothesis. Available data suggest that at several levels of information processing in the nervous system, older adults show evidence of a deficit in inhibitory function. Although the evidence is not unequivocal, the following generalization can be made: older adults are less selective information processors than are younger adults. In a variety of situations ranging from elicitation of a brain-stem reflex to the execution of higher language functions, in which both relevant and irrelevant information are available for processing, older adults are more likely to process both classes of information, rather than restricting processing to the most relevant information. The theoretical notion of an inhibitory deficit has been applied with some success in accounting for empirical observations, both in direct tests with models that specifically invoke inhibitory function and less direct tests with tasks for which inhibitory processes are assumed to be relevant.