ABSTRACT
Psychology.—Aging is a process that leads not only to physical and physiological weakening (see neuroscience below), but also to the slow deterioration of mental functions. Cognition in the elderly is characterized by a decline in the information-processing systems (→INFORMATION) that results in slower processing, generally manifested as an increase in reaction time. The decline is not uniform: it is greater for some cognitive functions such as memory than it is for others like language (→LANGUAGE, MEMORY). And even within one and the same function, some processes may be less adversely affected than others. This fact has made it possible to dissociate the different components of memory: when tested specifically, working memory and episodic memory appear to be altered the most. In addition, the data very often bring out substantial interindividual variability (→DIFFERENTIATION). Increasing heterogeneity of cognitive performance with age and across individuals is a basic indicator of aging, and therefore should be explored as such.
