In one type of association-memory paradigm, after studying pairs of the form AB, AC, participants must recall both B and C in response to A. Counterintuitively, yet often replicated, recall probabilities of B and C are typically uncorrelated ("associative independence"). This face-value independence is now understood to reflect a negative correlation due to AB and AC competing, approximately offset by a positive correlation produced by subject- and item-variability. The outcome might vary with stimulus material; for noun-pairs, and with a single study trial per pair, AB and AC have been found to be positively correlated. We replicated the positive correlation between AB and AC for noun-pairs, but this did not differ from the correlation expected for independent memory tests, suggesting that for noun pairs, AB and AC are independent on average. In Experiment 2, participants instructed to form separate images for AB and AC again produced an independence pattern, but participants instructed to combine AB and AC into an integrative image produced a facilitation pattern. Thus, the relationship between AB and AC varies, and can be influenced by study strategy. Association-memory models may need to accommodate a diverse range of AB-AC relationships, and studies that build on AB/AC learning may need to consider whether AB/AC start out with a competitive, facilitatory or independent relationship.

Healthy older adults are more challenged by associative interference than younger adults, but prior results could have been due to differences in list discrimination ability. We used a procedure that assessed interference without requiring knowledge of list membership to test the hypothesis that older adults (60 -74 years old) would show more pronounced effects of associative interference in AB/AC learning. Despite our use of a self-paced, rather than timed, study procedure, older adults performed at lower levels of accuracy than younger adults, replicating the well established associative deficit in aging (Naveh-Benjamin & Mayr, 2018). Older participants also displayed more proactive interference on average. Older participants' memory for AB and AC showed statistical independence, resembling earlier data from younger participants with a timed study procedure (Burton, Lek, & Caplan, 2017). However, younger participants, with the current self-paced procedure, produced a facilitating relationship between memory for AB and AC. Thus, younger participants not only resolved, but reversed associative interference. List discrimination could not explain these age differences. Taken together, these results extend the associative deficit in aging, finding increased susceptibility to associative proactive interference and less resolution of associative interference in older than younger participants, even when given the opportunity to compensate during self-paced study.