Task conflict and proactive control: A computational theory of the Stroop task.

Abstract

The Stroop task is a central experimental paradigm used to probe cognitive control by measuring the ability of participants to selectively attend to task-relevant information and inhibit automatic task-irrelevant responses. Research has revealed variability in both experimental manipulations and individual differences. Here, we focus on a particular source of Stroop variability, the reverse-facilitation (RF; faster responses to nonword neutral stimuli than to congruent stimuli), which has recently been suggested as a signature of task conflict. We first review the literature that shows RF variability in the Stroop task, both with regard to experimental manipulations and to individual differences. We suggest that task conflict variability can be understood as resulting from the degree of proactive control that subjects recruit in advance of the Stroop stimulus. When the proactive control is high, task conflict does not arise (or is resolved very quickly), resulting in regular Stroop facilitation. When proactive control is low, task conflict emerges, leading to a slow-down in congruent and incongruent (but not in neutral) trials and thus to Stroop RF. To support this suggestion, we present a computational model of the Stroop task, which includes the resolution of task conflict and its modulation by proactive control. Results show that our model (a) accounts for the variability in Stroop-RF reported in the experimental literature, and (b) solves a challenge to previous Stroop models-their ability to account for reaction time distributional properties. Finally, we discuss theoretical implications to Stroop measures and control deficits observed in some psychopathologies. (PsycINFO Database Record

Monitoring and control in multitasking

“…This is different from response conflict, which arises when two competing response alternatives are activated. Evidence that task conflict can be dissociated from response conflict empirically has come from the observation that bivalent stimuli are associated with a cost relative to univalent stimuli (e.g., Braverman & Meiran, 2015;Elchlepp et al, 2013;Goldfarb & Henik, 2007;Kalanthroff, Davelaar, Henik, Goldfarb, & Usher, 2018;Monsell, Taylor, & Murphy, 2001;Rogers & Monsell, 1995;Steinhauser & Hübner, 2008. In a task-switching situation, conflict may be induced by a stimulus feature that is irrelevant to the current task, but would be relevant in the context of the other task (bivalent stimuli; e.g., a blue square or red circle, in the above example).…”

Strategies that reduce Stroop interference

“…An essential feature of the human cognitive system is its ability to attend to and utilise goalrelated stimuli while it ignores the distractors of the environment. The Stroop task (Stroop, 1935; for a review see MacLeod, 1991) provides a window into selective attention and since its publication it has inspired many theories of attention and cognitive control (Botvinick, Braver, Barch, Carter, & Cohen, 2001;Cohen, Dunbar, & McClelland, 1990;Engle & Kane, 2004;Kalanthroff, Davelaar, Henik, Goldfarb, & Usher, 2018;MacLeod & MacDonald, 2000). This task requires participants to name the displayed color of the presented words while they should disregard the meaning of the words.…”

Meta-control of the exploration-exploitation dilemma emerges from probabilistic inference over a hierarchy of time scales

“…Cognitive control is considered essential for some of the most advanced cognitive capacities of humans, such as the ability to pursue long-term goals and to respond flexibly to changing contexts and task demands. However, much of the experimental research on cognitive control has focused on relatively simple laboratory tasks, as, for instance, interference paradigms such as Stroop or flanker task (e.g., Kalanthroff et al 2018;Scherbaum et al 2011), or paradigms assessing cognitive flexibility such as task switching (Koch et al 2018). Many of these tasks are aimed at inducing conflicting internal representations, which trigger responses that are in contradiction to the instructed task goal and may lead to an incorrect response.…”