An overall decline both in recollection and familiarity in healthy aging

Background: In the area of recognition memory, the experimental data have been inconsistent about whether or not familiarity declines in healthy aging. A recent meta-analysis concluded that familiarity is impaired when estimated with the remember-know procedure, but not with the process- dissociation procedure. Method: We present an associative recognition experiment with remember-know judgments that allow us to estimate both recollection and familiarity using both procedures in the same task and with the same participants (a sample of healthy older people and another sample of young people). Moreover, we performed a within-subjects manipulation of the type of materials (pairs of words or pairs of pictures), and the repetition or not of the pairs during the study phase. Results: The results show that familiarity, estimated using both estimation procedures, declines significantly with age, although the effect size obtained with the process- dissociation procedure is significantly smaller than the one obtained with the remember-know procedure. Conclusions: Our results show that aging is associated with significant decreases both in recollection and, to a lesser extent, familiarity