Aging and Effort Expenditure: The Impact of Subjective Perceptions of Task Demands

Engagement in cognitively demanding activities has a positive impact on cognitive health in older adults. Previous work, however, has suggested that the costs associated with engagement increase in later life and influence motivation. We examined how subjective perceptions of these costs varied with age and influenced task engagement. The following questions were of specific interest: (a) Are there age differences in subjective perceptions of cognitive costs? (b) What is the impact of these perceptions on engagement? We tested 39 older (ages 65-84) and 37 younger (20-42) adults on a working memory task. Systolic blood pressure responsivity (SBP-R; reflective of effort) and subjective perceptions of task difficulty were assessed. We found that age was associated with an increase in the perceptions of cognitive costs, and that these subjective perceptions had a stronger impact on older adults' engagement than on that of younger adults. More important, this impact was specific to subjective perceptions of cognitive costs. The results provide further support for the hypothesis that increased costs associated with cognitive engagement influence older adults' willingness to engage cognitive resources, and that these costs in part reflect subjective perceptions that are independent of objective task demands.