Perceptual Load Modulates the Effect of Cross-modal Correspondence on Visual Working Memory Performance

Cross-modal correspondence refers to systematic association between features across sensory modalities, such as lightness and pitch. While previous research suggests that correspondence enhances working memory, the conditions under which these effects emerge remain unclear. This study examined how lightness and pitch audiovisual correspondence influences visual working memory using an orientation change detection task, with visual stimuli paired with high- or low-pitched sounds across corresponding, non-corresponding, and visual-only conditions. We also manipulated perceptual load, memory stage (encoding vs. recall), and attentional focus on the auditory modality. Our design enabled us to isolate the contribution of cross-modal correspondence under varying cognitive demands. Under low load, sounds improved performance regardless of their correspondence, likely by enhancing alertness. Under high load, performance improved only when audiovisual correspondence was present and irrespective of attentional allocation. These findings suggest that lightness-pitch correspondence influences memory under increased cognitive demands, supporting predictions from Bayesian models of learned associations.