We provide a comprehensive investigation of proactive and reactive control during Stroop task performance with younger, middle-aged, and older adults, to test predictions of the Dual Mechanisms of Control (DMC) framework. A novel color-word vocal response paradigm was utilized with separate baseline, proactive, and reactive conditions, which differed in list-level and item-specific proportion congruencies, along with matched and randomly alternating color naming and word reading blocks. When compared to baseline, the proactive condition indexes processes that actively maintain goal-relevant information during contexts in which distraction is expected, while the reactive condition indexes dynamic adjustment processes engaged when items associated with high cognitive control demands are unpredictably encountered. Using a large sample (N = 327) and targeted analyses measuring primary and secondary behavioral markers of proactive and reactive control, the findings strongly indicate that while younger adults demonstrate robust engagement of proactive control mechanisms, proactive control effects were absent in older adults, and diminished in middle-aged adults, suggesting a lifespan related pattern of change. In contrast, the results highlight the selectivity of the proactive pattern, as indices of reactive control did not exhibit age-related change, nor were there any effects of proportion congruency in matched word reading blocks. Together, the findings provide strong confirmation of the DMC framework, in suggesting a tight linkage between proactive control capacity and the dynamic neurocognitive processes that change across the adult lifespan.
Ileri-Tayar et al. (Mon,) studied this question.