Prefrontal overrecruitment in older adults: Task demand–dependent efficiency and implications for cognitive aging.

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This study provided strong evidence for a graded, capacity-limited model of neural compensation in aging, consistent with the CRUNCH and STAC-r frameworks. Frontal overactivation was initially associated with adaptive responses but became maladaptive under high demand (MS–4L), suggesting limits to compensatory mechanisms. These findings extend prior research by demonstrating gradual declines in compensation shaped by task complexity and regional specialization. Practically, the findings suggest that tracking the trajectory of IESs across escalating task demands (from 4L to 8L to FD to MS) could offer a sensitive behavioral indicator of cognitive vulnerability in older adults. A steeper IES slope—reflecting a sharper efficiency drop under increasing cognitive load—may help identify individuals at greater risk for age-related decline. These insights underscore the value of adjusting task complexity to better align with individuals’ cognitive capacity at different ages, not only in cognitive assessments but also in the design of training environments, workplace demands, and everyday public settings. Tailored cognitive training paradigms that scaffold task demands and foster more efficient recruitment of cognitive resources could support cognitive health and enhance age-friendliness in diverse applied contexts.

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