When twice is better than once: increased liking of repeated items influences memory in younger and older adults

Numerous studies have reported that the repeated presentation of a stimulus leads to an increase in positive affect towards the stimulus itself (the so-called mere exposure effect). Here, we evaluate whether changes in liking due to repetition may have a differential impact on subsequent memories in younger and older adults.

Decades of studies have shown that repeated exposure to a stimulus can lead individuals to consider the stimulus as more pleasant. This effect, known as the mere exposure effect, suggests that information deriving from repetitions may have an impact on the cognition-emotion interaction. Repetition, in fact, may carry a positive connotation and/or orientate emotional reactions towards the positive pole. In this study, we assume that repetition influences emotional preferences (like/dislike ratings) and that these preferences differentially affect subsequent memory.

Memory, repetition, and the mere exposure effect

Decades of experimental studies have shown that repetition leads to better memory. This effect can be explained from a cognitive perspective where repetition strengthens memory traces that subsequently aid individuals during retrieval There are multiple variations of the processing fluency approach, but what is relevant here is that the level of fluency may differ across stimuli and this may impact emotional memories of younger and older adults in different ways. 

Finally, it would be also interesting to adopt a remember/know paradigm to better highlight the role of familiarity and recollection in older adults’ greater focus on items they liked most, e.g., whether older adults consciously retrieve contextual details (in this case their liking judgment) that were associated with the item at the time of encoding or just know that the item was on the list even though they cannot recall any specific information about its prior occurrence. Our results seem to point to a recollection-based hypothesis of positivity effects as older adults’ recognition focused on the items, they liked most among a series of items they remembered overall.