AGE-DIFFERENCES IN THE TEMPORAL DYNAMICS OF LETTER MATCHING

Age differences were examined in 18 young and 18 older adults in perfo rmance for a sequential letter-matching task in which stimulus onset a synchrony (SOA) was varied from 0.2 s to 7.5 s (0.2, 0.5, 1, 2, 5, and 7.5 s). The same-different matching task used Posner's Task (Posner & Mitchell, 1967), where both physical identity (e.g., A-A) and nominal identity matches (e.g., A-a) are considered same stimuli and where le tters with different identities (e.g., A-B; A-b) are considered differ ent. Results indicated that older adults were slower and made more err ors than young adults did. Young and older adults both made more error s and responded more slowly at longer SOAs than at shorter SOAs. An Ag e x SOA interaction showed older adults' latencies to be more adversel y affected than those of young adults by the longer SOAs. Letter-match condition affected performance, but neither age nor SOA interacted wi th type of letter match. These results suggest an age-related deficit in speed of delayed letter matching, where older adults have more diff iculty than young adults in maintaining and/or retrieving information necessary to make a delayed letter match.