Proactive control in the Stroop task: A conflict-frequency manipulation free of item-specific, contingency-learning, and color-word correlation confounds.

Abstract

In the Stroop task, congruency effects (i.e., the color-naming latency difference between incongruent stimuli, e.g., the word BLUE written in the color red, and congruent stimuli, e.g., RED in red) are smaller in a list in which incongruent trials are frequent than in a list in which incongruent trials are infrequent. The traditional explanation for this pattern is that a conflict-monitoring mechanism adjusts attention to task-relevant versus task-irrelevant information in a proactive fashion based on list-wide conflict frequency. More recently, however, multiple alternative explanations have been advanced that could explain the pattern without invoking this form of proactive control: Individuals might only adapt to conflict frequency specific to individual items (as opposed to list-wide conflict frequency), they could learn word-color contingencies (e.g., how often a particular word and color are paired), or they could adapt attention based on whether the words are informative of the color (even if many word-color pairings are incongruent) in the list as a whole. To examine this issue, we designed a new paradigm that should eliminate any impact of these alternative mechanisms. In that paradigm, the proportion of neutral (e.g., XXX in red) and incongruent stimuli was manipulated across lists. Paralleling the results in the original paradigm, there was a smaller latency difference between incongruent and neutral stimuli in a list in which incongruent trials were frequent than in a list in which incongruent trials were infrequent, suggesting that proactive control in response to list-wide conflict frequency is a process humans can and do use.

Can the Stroop effect serve as the gold standard of conflict monitoring and control? A conceptual critique

“…Consequently, control studies of Stroop manipulate the number of incongruent or congruent stimuli in the stimulus ensemble as a means of creating or reducing conflict and control. What is not realized though is that the same manipulation automatically creates color-word correlation and wordresponse correlation in the same stimulus ensemble (see Algom & Chajut, 2019;Hasshim & Parris, 2021;Spinelli & Lupker, 2020, on the difference between color-word correlation and word-response contingency). These stimulus factors have nothing to do with conflict or top-down control, yet they generate all of the effects attributed to conflict and control.…”

Working memory load dissociates contingency learning and item-specific proportion-congruent effects.

“…Although conflict-adaptation and contingency-learning mechanisms are not necessarily mutually exclusive and could be integrated within a common theoretical framework (Abrahamse, Braem, Notebaert, & Verguts, 2016; Egner, 2014), in recent years there has been a debate about whether contingency learning alone may be a sufficient explanation for proportion-congruent effects, that is, whether these effects can be explained by an account that does not require invoking a mechanism of adaptation to conflict frequency at all (e.g., Atalay & Misirlisoy, 2012, 2014; Bugg, 2014; Bugg et al, 2011; Bugg & Hutchison, 2013; Hazeltine & Mordkoff, 2014; Hutchison, 2011; Schmidt, 2013a, 2013b, 2013c; Schmidt & Besner, 2008; Schmidt et al, 2015). More recently, however, some evidence has emerged suggesting that list-wide proportion-congruent effects do persist when controlling for both contingency learning (Bugg, 2014; Bugg & Chanani, 2011; Gonthier et al, 2016; Hutchison, 2011; Spinelli & Lupker, 2020b; Spinelli, Perry, & Lupker, 2019) and learning of list-wide temporal expectancies, another nonconflict learning mechanism thought to contribute to generating list-wide proportion-congruent effects (Cohen-Shikora, Suh, & Bugg, 2019; Spinelli et al, 2019). These results support the claim that humans do have access to a proactive mechanism of adaptation to list-wide frequency of conflict (for counterarguments, see Schmidt, 2013c, 2014, 2017).…”

No need to choose: independent regulation of cognitive stability and flexibility challenges the stability-flexibility tradeoff

“…A substantial literature supports the idea that on-task focus (stability) is regulated via a control feedback loop that tracks ongoing variations in task difficulty (assessed via the proxy of conflict in information processing) and implements a commensurate up-or down-regulation of the strength of task set representations in working memory (Botvinick et al, 2001; for recent reviews, see Chiu & Egner, 2019;Egner, 2017). Thus, encountering a sequence of mostly congruent trials would result in a relatively low level of conflict-driven task focus, whereas a sequence of mostly incongruent trials would promote a strongly activated task set, leading to the LWPC effects (e.g., Spinelli & Lupker, 2020). As noted in the Introduction, a commonly proposed mechanism of task-set updating is a gating process whereby the gate to working memory (holding the task set) is opened in response to cues of changing incentives or task requirements, in order to switch out task sets (Frank et al, 2001;Hazy et al, 2006).…”