Age-related differences in information, but not task control in the color-word Stroop task.

Abstract

Older adults were found to struggle with tasks that require cognitive control. One task that measures the ability to exert cognitive control is the color-word Stroop task. Almost all studies that tested cognitive control in older adults using the Stroop task have focused on one type of control - Information control. In the present work, we ask whether older adults also show a deficit in another type of cognitive control - Task control. To that end, we tested older and younger adults by isolating and measuring two types of conflict - information conflict and task conflict. Information conflict was measured by the difference between color identification of incongruent color words and color identification of neutral words, while task conflict was measured by the difference between color identification of neutral words and color identification of neutral symbols and by the reverse facilitation effect. We tested how the behavioral markers of these two types of conflicts are affected under low task control conditions, which is essential for measuring task conflict behaviorally. Older adults demonstrated a deficit in information control by showing a larger information conflict marker, but not in task control markers, as no differences in task conflict were found between younger and older adults. These findings supported previous studies that work against theories that link the larger Stroop interference in older adults to a generic slowdown or a generic inhibitory failure. We discussed the relevancy of the results and future research directions in line with other Stroop studies that tested age-related differences in different control mechanisms.