Unveiling the gist: Differential dynamics in information sampling between younger and older adults

In previous visual and memory search (hybrid search) experiments, we have observed that older adults (OA) show differences beyond age-related slowing in reaction times compared to younger adults (YA) under high memory load, particularly when distractors share the same basic category as the target. This effect increases with the number of items of the target category present in the visual display, especially in target absent trials. Eye-tracking research suggests this slowing is driven by OA dwelling longer on distractors and often revisiting previously inspected areas, particularly when target-distractor similarity is high. It is possible that this behaviour reflects a need from OA to gather more evidence to distinguish targets from distractors. We hypothesize that these differences are related to a difference in memory representations. While YA may keep verbatim representations, OA may rely on more gist-like representations. Relying on gist-like representation would require OA to sample more information to reach a decision threshold. The present project aims to quantify the information that YA and OA sample before reaching a decision, and how this sampling is differentially influenced by memory and category load.