ABSTRACT
The arousal model provides one example of a “direct hit” or mechanical model in that changes in performance competence are assumed to occur as a direct result of changes in internal energy level. An alternative is what might be described as the “mental load” model; the main assumption is that as mental work load or demand increases, errors will occur on a secondary or non-salient aspect of a task as capacity is exceeded. The mental load model has been traditionally reserved for the relationship between workload and task performance. However there is evidence to suggest that stress increases mental demand. Explanations of stress effects in terms of increased workload provide a viable alternative to the arousal model.
