A study of adaptive behavior: effects of age and irrelevant information onthe ability to inhibit one's actions

In the study of adaptive behavior, the stop-signal paradigm provides a meas ure of the efficiency of response suppression that lends itself to examinin g the ability to inhibit one's actions, and two complementary types of fact ors that may influence that ability. Based on neurobiological consideration s, age-related individual differences were hypothesized to be such a factor . In agreement with the the cognitive-neuroscience literature, which emphas izes the relatively late maturation and early senescence of the (pre)fronta l brain structures that are crucial for inhibitory control, results are rep orted of a study demonstrating that response inhibition in the stop task is subject to an unequivocal age trend during child development. Stop task performance was hypothesized to be influenced further by the effe cts of irrelevant information. In a concurrent reaction time task, distract er stimuli may induce activation of an incorrect response. The subsequent i nhibition of this incorrect response activation may interact with the suppr ession of responses in the stop task, if both are engaged simultaneously. I ndeed, in a study designed to examine this prediction, the operation of res ponse inhibition in the primary-task and stop processes affected one anothe r negatively when distracters were associated with the incorrect response. (C) 1999 Elsevier Science B.V. All rights reserved. PsycINFO classification : 2260; 2330; 2340; 2820.