Effects of Aging on Subjective Workload and Performance

Abstract

Demographics indicate that the population in the United States and other industrialized nations is growing older, and that the number of older workers and systems users can be expected to increase substantially over the next several decades. In order to assess possible differences between age groups the mental workload experienced by older adults as compared to that experienced by younger adults was investigated. Two tasks were utilized to assess short term memory (continuous recognition) and psychomotor (first-order unstable tracking) performance. The workload of each task was assessed with the Subjective Workload Assessment Technique (SWAT). Memory task performance measures and subjective workload ratings indicated a decrement in performance and an increase in workload for the older group relative to the younger group. Psychomotor task performance measures and subjective workload ratings indicated no difference between the age groups. It is hypothesized that the memory task makes greater demands on central processing resources than the psychomotor task used in this study. In support of this hypothesis, an analysis of the changes in ratings on the individual SWAT dimensions of time, mental effort and psychological stress revealed that an increase occurred only on the mental effort dimension for the memory task. This study implies that designers should 1) reduce or provide design features that lessen memory laden task performance for older workers, and 2) give more weight to the reduction of central processing resource requirements in trade-off studies.