ABSTRACT
In modern combat environments information superiority and the associated communication systems are paramount to operational success. Considerable efforts have and are being applied to the tasks of gathering, collating, synthesizing, and conveying this vital information. The same level of energy needs to be brought to bear in devising innovative and effective methods for communicating this information to the end user; the soldier. The modality in which the information is presented is critical in this process in that it differentially influences behavioral response, especially when tasks are either learned or subsequently performed in stressful circumstances. The multiple attentional resource theory (Wickens, 1980, 2002) has had a particularly strong influence on the professional practice of human factors, especially in interface development where it arguably remains the strongest behavioral heuristic for system design. In identifying the visual and auditory modality Wickens specified the two major avenues through which any individual usually assimilates sensory information. However, this does not exhaust all the input processing possibilities. The multiple resource model accounts mostly for situations where task demand is high (overload) and much less for situations where the demands are low that is the critical and often hidden issue of underload (and see Warm, 1984). Mismatch between task and environmental demand and the individual can induce stress and degrade performance. Dynamic models of stress and attention (Hancock and Warm, 1989) are based on the notion of adaptation to task demands. The Hancock and Warm model suggests that it is difficult to adapt to conditions of both under-load and over-load. According to this model, the individual is often able to compensate for dynamic variations in workload and environmental factors that moderate levels of stress. As such, when task demands are relatively low, the modality of presentation appears to be of somewhat less importance and operators are able to process information with less sensitivity to presentation modality. Alternatively, when task demands are high, the modality of presentation becomes critical and plays a significant role in operator effectiveness. In this chapter, we examine the effects of cross-modality of information presentation and retention from an applied perspective. Our focus is mainly on summarizing results from experiments conducted under the MURI-OPUS research program. Through examining data from various systematic studies, we aim to identify theoretically consistent patterns (and exceptions to these patterns) in order to direct attention to gaps in knowledge and theory. This bottom-up approach is vital for the development of future advances in theory and subsequent design practice for interface development in stressful conditions.
