Presenting features audiovisually improves working memory for bindings

It has long been known that presenting information to multiple senses at a time (e.g., audiovisual presentation as opposed to only visual or auditory) improves later recall of said information – an effect known as the bimodal advantage. Surprisingly however, evidence for this has come only from studies employing free and serial recall, where the identity of an object is recalled, but not in cued recall, where one object feature is recalled when another one is cued. This is despite both tasks requiring binding features into an object in working memory (WM) – our brain’s capacity-limited system for temporarily maintaining information for the purpose of achieving behavioral goals. The present study investigated this discrepancy across a series of four experiments. Contrary to the literature, and despite near-identical task settings, we found evidence for a bimodal advantage across multiple experiments. Moreover, our results suggest that this advantage mainly arises from perceptual processes at encoding rather than from storage in an audiovisual fashion in WM. Finally, a primarily perceptually-based process, the bimodal advantage appears to be sensitive to the characteristics of the cue feature (i.e., its presentation modality). In sum, our results shed light on the mechanism of the bimodal advantage, now robustly detected in cued recall tasks, furthering our understanding of the relationship between perception and WM. Results are discussed in relation to prior studies that did not find a bimodal advantage, potential mechanisms underlying the effect, and the broader framework of the multicomponent model of WM.