The role of vocabulary ability during visual word recognition in younger and older adults

The role that vocabulary ability plays in adult age differences in word rec ognition was investigated. In Experiment I, 44 older adults ages (61-93 yea rs) were compared with 44 younger adults (ages 18-39 years) on a standard l exical-decision task, with ambiguous words, unambiguous words, and pseudowo rds serving as stimuli. In Experiment 1, the Wechsler Adult Intelligence Sc ale-Revised (WAIS-R; D. Wechsler, 1981) vocabulary performance was uncontro lled across: the younger and older adults, and the older adults had higher WAIS-R scores. There was no Group x Stimulus interaction. In Experiment 2, the data from the same 44 older adults were compared with data from a new s ample of 44 younger adults (ages 18-44). Both groups were then matched on W AIS-R performance. Results revealed a significant Group x Stimulus interact ion. Reaction time differences between the younger and older groups on the ambiguous words and unambiguous words were identical. The differences in re action times for words and pseudowords were greater in the older adults. Th e importance of vocabulary ability during word recognition and lexical proc essing is discussed.