Adaptation to Frequent Conflict in the Eriksen Flanker Task

Abstract

We examined adaptation to frequent conflict in a flanker task using event-related potentials (ERPs). A prominent model of cognitive control suggests the fronto-central N2 as an indicator of conflict monitoring. Based on this model we predicted (1) an increased N2 amplitude for incompatible compared to compatible stimuli and (2) that this difference in N2 amplitude would be less pronounced under conditions of frequent conflict (high cognitive control). In this model, adaptation to frequent conflict is implemented as modulation of early visual processing. Traditionally, variations in processing selectivity in the flanker task have been related to a zoom lens model of visual attention. Therefore, we further predicted (3) effects of conflict frequency on early visual ERP components of the event-related potential, and (4) generalization of conflict adaptation due to increased conflict frequency in the flanker task to other visuospatial tasks, intermixed within flanker task trials. Frequent conflict was associated with reduced flanker interference in response times (RTs) and error rate. Consistent with the literature, amplitude of the fronto-central N2 was larger and latency of the central P3 longer for incompatible stimuli. Both effects were smaller when conflict was frequent, supporting the notion of fronto-central N2 as indicator of conflict monitoring. Neither amplitude nor latency of the posterior P1, as index of early visual processing, was modulated by conflict frequency. Additionally, conflict frequency in the flanker task did not affect the pattern of RTs in a probe task. In sum, our results suggest that conflict adaptation operates in a task-specific manner and does not necessarily alter early information processing, that is, the spatial focus of visual attention.

Differential modulation of the N2 and P3 event-related potentials by response conflict and inhibition

“…According to this model, the N2 is modulated in inhibitory control tasks because the ratio of go to no-go or stop trials creates conflict between the prepotent response tendency and the infrequent requirement to inhibit the response (Braver, Barch, Gray, Molfese, & Snyder, 2001), not because of inhibition per se. In support of this, N2 amplitude is greater on go than no-go trials when the ratio of go: no-go trials is reversed (Donkers & van Boxtel, 2004;Enriquez-Geppert et al, 2010;Nieuwenhuis, Yeung, van den Wildenberg, & Ridderinkhof, 2003) and on incongruent than congruent flanker trials in the visual flanker 6 task (Bartholow et al, 2005;Clayson & Larson, 2011;Purmann, Badde, Luna-Rodriguez, & Wendt, 2011). In the flanker task participants must respond to a central target stimulus while simultaneously suppressing an opposing response associated with the flanking stimuli.…”

Dissociable early attentional control mechanisms underlying cognitive and affective conflicts

“…In particular, the amplitude of the conflict-related N2 is augmented in the LPC context910 (but see also ref. 11), and this is associated with reduced interference effects. These effects echo the conflict-monitoring theory which maintains that infrequent incongruent trials in the HPC context decrease the level of control, producing a stronger interference effect; in contrast, frequent incongruent trials in the LPC context presumably lead to a steady maintenance of a high level of control, producing a weaker interference effect12.…”

“…These effects echo the conflict-monitoring theory which maintains that infrequent incongruent trials in the HPC context decrease the level of control, producing a stronger interference effect; in contrast, frequent incongruent trials in the LPC context presumably lead to a steady maintenance of a high level of control, producing a weaker interference effect12. Furthermore, the sustained potential (SP), a late conflict-related component, is also modulated by the PC, such that its amplitude is augmented and associated with a larger interference effect in the HPC context compared to the LPC one9111314. Regarding the localization of these conflict-relevant components, accumulating evidence indicates that the N2 component is generated in the dorsal anterior cingulate (dACC)1516 or the dorsolateral prefrontal cortex (DLPFC)1718, reflecting the detection of conflict or conflict maintenance, while the SP component is generated in the lateral frontal and extrastriate cortices and thought to reflect conflict resolution419.…”

How effortful is cognitive control? Insights from a novel method measuring single-trial evoked beta-adrenergic cardiac reactivity

“…Given previous findings showing increased behavioral interference in blocks in which the proportion of conflict trials is low (e.g. Gratton et al, 1992;Purmann et al, 2011), we expected that low-conflict compared to high-conflict blocks 1) leads to more pronounced transient enhancements of effort, reflected by a larger effect of conflict on RZ following stimulus onset; and, 2) might be associated with reduced sustained effort, reflected by an increased RZ during the pre-stimulus baseline period.…”

“…This adaptation to conflict improves subsequent performance and is thought to reflect transient enhancements in cognitive control. In addition, when the proportion of conflict trials across a task block is high, these adaptations result in an overall reduction in the behavioral susceptibility to conflict, suggesting improved sustained cognitive control during a high-conflict task block (Botvinick et al, 2001;Gratton, Coles, & Donchin, 1992;Purmann, Badde, Luna-Rodriguez, & Wendt, 2011).…”