The Effects of Modality and Stress across Task Type on Human Performance

This investigation integrates four different approaches to the study of attention and multiple task performance, to include the effects of stimulus modality presentation, the influence of spatial separation in visual stimulus presentation, the effects of stress, and the influence of task type (dual-task versus information-integration task), in a spatial vector monitoring task. A significant benefit of cross-modal (visual-auditory) presentation was found when information was integrated at both levels of stress, while an interaction between modality and stress level occurred in the dual task condition, favoring the intra-modal (visual-visual) presentations at the lower stress level. The auditory display tended to be more stress resistant. The results support Kahneman's concept of stress-related resource expansion, provide weak support for perceptual narrowing, and provide little support for a processing modalities dimension of the Multiple Resource Model. Instead, they are consistent with the concept of auditory pre-emption, discussed by Wickens (1987).