How list composition affects the emotional enhancement of memory in younger and older adults.

Young adults show an immediate emotional enhancement of memory (EEM) when emotional and non-emotional information are presented in mixed lists but not pure lists, but it is unclear whether older adults' memories also benefit from the cognitive factors producing the list-composition effect. The present study examined whether the list-composition effect extended to older adults (55+), testing the following alternatives: (1) younger and older adults could show the list-composition effect, (2) due to age-related decreases in cognitive resources, older adults may show weaker effects of list-composition, or (3) due to age-related positivity effects, older adults' list-composition effect may vary by valence. Results supported the first alternative: the list-composition effect occurred for older as well as younger adults, when testing memory for pictures (Experiment 1) or words (Experiment 2). In a third experiment, we explored whether mixing information at only encoding or retrieval (and blocking in the other phase) would suffice for the list composition effect to occur. Results revealed that mixed encoding/blocked retrieval did not elicit the EEM in either age group. Overall, the results suggest age-related stability in the cognitive processes that give rise to the immediate EEM.