Object memory is multisensory: Task-irrelevant sounds improve recollection-based recognition memory

Abstract

Hearing a task-irrelevant sound during object encoding can improve visual recognition memory when the sound is object-congruent (e.g., a dog and a bark). However, previous studies have only used binary old/new memory tests, which do not distinguish between recognition based on the recollection of details about the studied event or stimulus familiarity. In the present research, we hypothesized that hearing a task-irrelevant, but semantically congruent natural sound at encoding would facilitate the formation of richer memory representations, resulting in increased recollection of details of the encoded event. Experiment 1 replicated previous studies showing that participants were more confident about their memory for items that were initially encoded with a congruent sound compared to an incongruent or meaningless sound. Experiment 2 suggests that multisensory presentations specifically facilitate recollection and not familiarity-based recognition memory, and Experiment 3 demonstrates that this effect was coupled with more accurate memory for audiovisual congruency of the item and sound from encoding. These results suggest that even when congruent sounds are task-irrelevant, they produce a qualitative change in memory formation that supports recollection-based recognition memory. Given the ubiquity of encounters with multisensory objects in our everyday lives, considering their impact on episodic memory is integral to building models of memory that apply to naturalistic settings.