Cognitive exertion and subsequent intention execution in older adults

Objectives. Previous studies have demonstrated that increasing the demands of a prospective memory task is detrimental to older adults' performance; however, no studies have investigated how prior cognitive demands influence subsequent prospective memory. The present study sought to address this gap by using a resource depletion paradigm. Methods. A sample of 107 older adults whose ages ranged from 60 to 85 years (M = 71.91, SD = 7.12) completed an initial task that was either cognitively taxing or relatively easy followed by either an attention-demanding prospective memory task or one that required minimal attentional resources. Results. Initial cognitive exertion led to decrements in prospective memory performance in the attention-demanding situation, particularly for the old-old participants (age ≥ 72); however, prior cognitive exertion did not influence subsequent prospective memory performance when the prospective memory task required minimal attentional resources. Discussion. This study extends the negative effects of prior cognitive exertion to prospective memory in older adults. Also, dovetailing with past work, the depletion effects were limited to prospective memory tasks that are thought to require demanding attentional processes. The depletion effects were most pronounced for the old-old, suggesting that increased age may be associated with decline in attentional resources.