Dissociating task, semantic, and response conflict in cognitive aging: evidence from a low-cognitive control Stroop paradigm.

Abstract

Cognitive aging is often associated with increased Stroop interference, but it remains unclear whether this reflects a broad decline in inhibitory control or selective impairments in specific conflict-resolution mechanisms. The present study examined age-related differences in task conflict, semantic conflict, and response conflict using a low-cognitive-control Stroop paradigm designed to amplify conflict effects. Younger and older adults completed a manual color-identification task including neutral shapes, neutral words, color-associated words, non-response-set incongruent color words, and response-set incongruent color words. This design allowed us to dissociate response conflict, two components of semantic conflict, and task conflict within a single paradigm. Older adults showed larger response conflict than younger adults, along with modest age-related increases in both semantic relevance and semantic relatedness. In contrast, task conflict did not differ between age groups. These results suggest that age-related increases in Stroop interference are not best explained by a single global inhibitory deficit. Rather, under the present manual-response, reduced-control conditions, older adults showed greater semantic and response-level conflict, whereas task conflict remained comparable across age groups. This dissociation is consistent with a more fine-grained account of cognitive control in aging.