Original article

Scand J Work Environ Health 2005;31(2):152-159    pdf

doi:10.5271/sjweh.862

Effect of aging on performance, muscle activation and perceived stress during mentally demanding computer tasks

by Alkjær T, Pilegaard M, Bakke M, Jensen BR

Objectives This study examined the effects of age on performance, muscle activation, and perceived stress during computer tasks with different levels of mental demand.

Methods Fifteen young and thirteen elderly women performed two computer tasks [color word test and reference task] with different levels of mental demand but similar physical demands. The performance (clicking frequency, percentage of correct answers, and response time for correct answers) and electromyography from the forearm, shoulder, and neck muscles were recorded. Visual analogue scales were used to measure the participants’ perception of the stress and difficulty related to the tasks.

Results Performance decreased significantly in both groups during the color word test in comparison with performance on the reference task. However, the performance reduction was more pronounced in the elderly group than in the young group. Likewise, a higher level of self-reported stress was found for the elderly participants after the color word test. During the reference task higher electromyographic levels and reported difficulty were recorded for the elderly group than for the young group.

Conclusions The findings suggest that mental demands affect young and elderly women differently. Thus the mentally demanding computer task had a more pronounced effect on the elderly than on the young. In contrast to the results in the reference task, the same level of muscle activity for most muscles and the same level of self-reported difficulty was found in the two groups during the color word test. The elderly probably compensated for age-related changes by reducing their work speed markedly.