Processing symmetry between visual and auditory spatial representations in updating working memory

Updating spatial representations in visual and auditory working memory relies on common processes, and the modalities should compete for attentional resources. If competition occurs, one type of spatial information is presumably weighted over the other, irrespective of sensory modality. This study used incompatible spatial information conveyed from two different cue modalities to examine relative dominance in memory updating. Participants mentally manoeuvred a designated target in a matrix according to visual or auditory stimuli that were presented simultaneously, to identify a terminal location. Prior to the navigation task, the relative perceptual saliences of the visual cues were manipulated to be equal, superior, or inferior to the auditory cues. The results demonstrate that visual and auditory information competed for attentional resources, such that visual/auditory guidance was impaired by incongruent cues delivered from the other modality. Although visual bias was generally observed in working-memory navigation, stimuli of relatively high salience interfered with or facilitated other stimuli regardless of modality, demonstrating the processing symmetry of spatial updating in visual and auditory spatial working memory. Furthermore, this processing symmetry can be identified during the encoding of sensory inputs into working-memory representations. The results imply that auditory spatial updating is comparable to visual spatial updating in that salient stimuli receive a high priority when selecting inputs and are used when tracking spatial representations.