Adaptive control in Stroop, Stroop-like, and Simon task types

Adaptive control-the ability to modulate attention based on contextual demands-is typically assumed to be a domain-general cognitive function. The function's actual domain-generality, however, remains unclear, as confound-controlled evidence for adaptive control is presently limited to the interference tasks used to examine it (typically, Stroop tasks) and the stimuli used in those tasks (typically, words and colors). We addressed these limitations by conducting a systematic examination of adaptive control in the three main interference-task types in the cognitive-control literature (i.e., Stroop, Stroop-like, and Simon, which are defined in terms of the degree of overlap between the targets, distractors, and responses used in those tasks) while varying the stimuli used in the tasks. The adaptive-control index we used was the Proportion-Congruent (PC) effect-the finding that, on confound-controlled trials, the effect of the distractor's congruency with the target on response time and accuracy is larger when the two are frequently congruent (e.g., RED in red) than when they are frequently incongruent (e.g., RED in blue). Across five experiments and seven different tasks with young adults (N = 432), we found robust PC effects in Stroop and Simon task types (in both types the distractor-associated response can conflict with the target-associated response) but not in Stroop-like task types (in which response conflict plays a weaker role). These findings establish the domain-generality of adaptive control but also suggest that response conflict is important for triggering adaptive control, a boundary condition that challenges extant adaptive-control models and will need consideration when revising them.