Determinants of Modality–Congruence Visual Dominance Effects During Selective Attention to Spatial Stimuli

Abstract Crossmodal interactions are common in tasks with information from multiple sensory modalities, and visual dominance often arises with incongruent sensory information. Visual dominance tends to be strong in spatial tasks with physical–spatial stimuli (e.g., stimuli in left and right locations), such that conflicting visual–spatial information impairs responses to auditory–spatial stimuli, but conflicting auditory–spatial information has less impact on visual–spatial processing. Strikingly, this pattern does not occur with verbal–spatial stimuli (e.g., the words “LEFT” and “RIGHT” as stimuli). Three experiments were conducted to examine the occurrence and underlying basis of this distinction. Participants were presented with either verbal–spatial or physical–spatial stimuli, simultaneously in the visual and auditory modalities, and were to selectively attend and respond to the spatial information in the cued modality. The distinct crossmodal congruence patterns for physical–spatial and verbal–spatial stimuli were found when the stimulus sets were blocked (Experiment 1) and when they were intermixed (Experiment 2). In addition, making verbal–spatial processing more frequent amplified the modality–congruence interaction for physical–spatial stimuli (Experiment 3). The consistent finding of the modality–congruence interaction showing visual dominance for physical–spatial stimuli but not for verbal–spatial stimuli under varying attentional conditions suggests that the effect is driven by the particular spatial sets based on their sensory properties rather than by attentional mechanisms.