Expectancy and choice reaction time in early and late adulthood

Abstract

Choice reaction time (CRT) was measured for young and elderly adults when both the stimulus and the response, or only the response, or neither the stimulus nor the response had been correctly predicted by the subject. The older adult's CRT exceeded the younger one's by a constant amount in all cases. Implications for the “uncertainty effect” in aging—the disproportionate increase with age of CRT relative to simple reaction time—are discussed.