Interplay of aging and practice in conflict processing: A big-data diffusion-model analysis

We are continually required to exercise cognitive control in order to separate relevant and irrelevant information. Previous studies have produced mixed results as to whether cognitive control declines across adulthood and improves with practice. Moreover, little is known about the influences of aging and practice on the automatic and controlled processes underlying performance in conflict situations. This calls for analyses of extensive data using process models for conflict tasks, akin to earlier drift-diffusion model analyses of performance in cognitive nonconflict tasks. Thus, to understand how aging and practice influence cognitive control at the process level, we analyzed a large-scale data set (1,800 participants aged 21-80 years completing 60 blocklike online games of an arrow-based Eriksen flanker task). At the coarse-grained level of mean response times, the congruency effect increased across adulthood and decreased with practice following an initial increase. The finer-grained distributional response time and error rate data were closely fitted by the diffusion model for conflict tasks, which captures the dynamic interplay of automatic and controlled processing. Best-fitting parameter values revealed multiple, partially counteracting influences of aging and practice: Aging across adulthood slowed down both controlled and automatic processing (besides slowing down nondecisional processes and increasing decision caution). By contrast, practice selectively speeded up controlled processing (besides speeding up nondecisional processes and decreasing decision caution). Taken together, these findings suggest that aging and practice primarily alter the speed of controlled (aging and practice) and automatic processing (aging), rather than causing inhibitory adjustments in the strength of automatic processing. (PsycInfo Database Record (c) 2025 APA, all rights reserved).