The Stroop Effect Occurs at Multiple Points Along a Cascade of Control: Evidence From Cognitive Neuroscience Approaches

Abstract

This article argues that the Stroop effect can be generated at a variety of stages from stimulus input to response selection. As such, there are multiple loci at which the Stroop effect occurs. Evidence for this viewpoint is provided by a review of neuroimaging studies that were specifically designed to isolate levels of interference in the Stroop task and the underlying neural systems that work to control the effects of interference at those levels. In particular, the evidence suggests that lateral prefrontal regions work to bias processing toward the task-relevant dimension of a Stroop stimulus (e.g., its color) and away from the task-irrelevant dimension (e.g., the meaning of the word). Medial prefrontal regions, in contrast, tend to be more involved in response-related and late-stage aspects of control. Importantly, it is argued that this control occurs in a cascade-like manner, such that the degree of control that is exerted at earlier stages influences the degree of control that needs to be exerted at later stages. As such, the degree of behavioral interference that is observed is the culmination of processing in specific brain regions as well as their interaction.

An fMRI Study of Response and Semantic Conflict in the Stroop Task

“…They showed that semantic conflict activated dorso-lateral prefrontal cortex (DLPFC: BA8/9), posterior parietal cortex (PPC: BA40) and the (ACC: BA32/6), whereas response conflict activated more inferior lateral prefrontal cortex (BA9/44/45/46), left premotor areas (BA6) and regions of the ACC (BA24/32) more anterior and ventral to that activated by semantic conflict (see also Chen et al, 2013, and Kim et al, 2010, for replications of this finding). This finding of ACC activation to semantic conflict conflicts with the Cascade-of-Control model (Banich, 2009, 2019). The authors argued that their findings were consistent with and extended the conflict monitoring account (Botvinick et al, 2001) by showing the involvement of separable regions of the ACC in monitoring for different types of conflict.…”

“…They also reported that both left and right PFC were activated by response conflict, but only left PFC was activated by semantic conflict, a finding that is inconsistent with previous imaging studies. The lack of ACC activation to semantic conflict indicates that the theorized conflict monitoring processes (Botvinick et al, 2001) are not processing all types of conflict, which is consistent with the Cascade-of-Control model (Banich, 2009, 2019).…”

“…Whilst our data do not allow us to conclude in favor of an arousal function of the ACC, this finding strongly contrasts with a the role of the ACC in conflict monitoring (e.g., Botvinick et al, 2001; Fellows and Farah, 2005; Roelofs et al, 2006; Aarts et al, 2008), and with the notion that separate regions of the ACC detect different forms of conflict (van Veen and Carter, 2005). However, this finding does not necessarily contradict the Cascade-of-Control model (Banich, 2009, 2019). The Cascade-of-Control model predicts a role for posterior and dorsal ACC in late stage, response selection, and more rostral ACC in conflict monitoring.…”

“…As noted above, ACC activation has been observed in neuroimaging studies of the Stroop task (Bench et al, 1993; Peterson et al, 1999; Adleman et al, 2002; Langenecker et al, 2004; Liu et al, 2004; Coderre et al, 2008) and, as noted, has been theorized to have an important role in Stroop task performance, particularly in detecting response conflict (Botvinick et al, 2001; Banich, 2009, 2019) and have separable regions for detecting response and semantic conflict (van Veen and Carter, 2005; cf. Milham et al, 2001).…”

“…The Cascade-of-Control model (Banich, 2009, 2019) is another model of the neural substrates of Stroop task performance based on a series of studies investigating control in Stroop-like tasks (e.g., Banich et al (2000a, b); Milham et al, 2002; Compton et al, 2003; Liu et al, 2006; Mackiewicz Seghete et al, 2017). According to this model, posterior portions of the lateral prefrontal cortex, particularly portions of the inferior frontal gyrus, are responsible for setting the attentional set in the Stroop task, meaning that it can upregulate color processing and/or downregulate word processing, prior even to stimulus onset (proactive control).…”