ABSTRACT
Previous conference papers in this series by the current authors (Young & Stanton, 1997; 1998; 1999) have reviewed literature on attention and mental workload, to synthesise a theory which could explain why extremely low task demands can be detrimental to performance. Studies of automated systems provided an ideal domain within which to explore the theories, as there had been many previous examples comparing the performance of active controllers against passive monitors. The literature review extracted mental underload as a specific problem for task performance, as many researchers had commented on the possible detrimental effects of excessively low mental demands. Whilst there was plenty of concern for the effects of underload, only a few (e.g., Desmond et al., 1998) had offered explanations as to why low demands had an adverse effect on performance.
