Behavioral and electrophysiological evidence for preserved specific associative episodic memory in older adults

Aging is often linked to a decline in associative memory. Prior research has shown that older adults have difficulty retrieving specific associative memory but can retrieve gist associative memory when deliberately differentiating test pairs with different levels of specificity during associative recognition. In this study, we utilized the context reinstatement paradigm to examine whether older adults could retrieve specific memory in situations where associations do not necessarily need to be voluntarily retrieved. Thirty-five older adults were directed to intentionally link objects with unique background scenes during encoding. Subsequently, test objects were presented against either the reinstated or similar background scenes during a recognition memory task, where participants were required to identify whether the objects were old or new regardless of their background contexts. Event-related potentials (ERP) were recorded to uncover the electrophysiological correlates of specific associative episodic memory. Behavioral results revealed higher memory sensitivity for object recognition when the background scenes were reinstated than when those were similar in older adults. ERP results indicated that older adults exhibited a more prominent fronto-centrally distributed positivity during object recognition in the reinstated than in similar contexts. Our results suggest that older adults may preserve their ability to retrieve specific memory for associations through an involuntary, spontaneous recollection process, which holds important theoretical implications for age-related associative memory deficits.