One-day retention of eyeblink classical conditioning and verbal free recall in young and older adults

The aims of this study were to: (a) investigate retention of a declarative and nondeclarative task in the same young and older adults, (b) assess self reports of awareness of learning during the nondeclarative task (eyeblink classical conditioning [EBCC]), and (c) examine two consecutive sessions of EBCC including one-day retest performance in EBCC paradigms that are more or less optimal for older adults. Eighty adults (40 young, 40 older) participated in two consecutive daily sessions of EBCC and a declarative task, the California Verbal Learning Test (CVLT). EBCC was performed by half the subjects using a 400 msec delay and half using a 750 msec delay EBCC paradigm. Age differences were observed in one-day retention for both the CVLT and EBCC. Young adults had more insight into EBCC performance than did older adults. There were large age differences in performance on both EBCC paradigms in both daily sessions, and performance did not improve in Session 2. EBCC is a form of nondeclarative memory that shows agerelated impairment in retention.