The ability to activate and inhibit speeded responses: Separate developmental trends

When children grow older they respond faster and are less susceptible to in terference caused by task-irrelevant information. These observations sugges ted the hypothesis that a global mechanism may account for developmental ch ange in the speed of responding and that inhibitory function may underlie t he ability to activate speeded responses. The current study examined these issues by comparing the performance of 4 age groups (5-, 8-, and 11-year-ol ds and young adults) on a battery of 6 speeded performance tasks, 4 of whic h required the inhibition of response activation. An analysis of reaction a nd inhibition times supported a hypothesis of generalized developmental cha nges in response activation, but revealed a less pronounced development of inhibition. A nonselective mechanism of response inhibition seems to be ful ly developed during early childhood. (C) 2000 Academic Press.