SPEED OF COGNITIVE PROCESSING IN AGING

Abstract

Mental slowness is a cognitive change probably associated with aging. We have studied the speed of mental scanning using the Sternberg paradigm. Two groups of normal subjects were compared regarding reaction time measures: a group of 26 young subjects (mean of age=25.0; SD=4.2) and a group of 26 older people (mean of age =70.3; SD= 5.3). Two-way analysis of variance (Group x Set Size) showed significant differences for both factors [Group: F = (1, 44) = 49.4, p < .001; Set Size: F(5,44) = 40.8, p < .001], and for the interaction Group x Set Size [F(1, 44) = 5.2, p < .001]. These results suggest that aging not only imply slowness in the choice reaction time, but also in the speed of mental processing. We think that the mental slowness is due to degenerative changes in white matter and basal ganglia.