Neural systems supporting the control of affective and cognitive conflicts

Abstract

Although many studies have examined the neural bases of controlling cognitive responses, the neural systems for controlling conflicts between competing affective responses remain unclear. To address the neural correlates of affective conflict and their relationship to cognitive conflict, the present study collected whole-brain fMRI data during two versions of the Eriksen flanker task. For these tasks, participants indicated either the valence (affective task) or the semantic category (cognitive task) of a central target word while ignoring flanking words that mapped onto either the same (congruent) or a different (incongruent) response as the target. Overall, contrasts of incongruent > congruent trials showed that bilateral dorsal ACC, posterior medial frontal cortex, and dorsolateral pFC were active during both kinds of conflict, whereas rostral medial pFC and left ventrolateral pFC were differentially active during affective or cognitive conflict, respectively. Individual difference analyses showed that separate regions of rostral cingulate/ventromedial pFC and left ventrolateral pFC were positively correlated with the magnitude of response time interference. Taken together, the findings that controlling affective and cognitive conflicts depends upon both common and distinct systems have important implications for understanding the organization of control systems in general and their potential dysfunction in clinical disorders.

Figure 1

Diagrammatic representation of the two main trial types used in the affective (top) and cognitive (bottom) flanker tasks. Each black square shows example stimuli that could be present on screen during a given incongruent or congruent trial. During the affective flanker task, target stimuli differ in valence from the flanking stimuli that appear above and below it. During the cognitive flanker task, target and flanker stimuli differ not in valence but in their semantic category. The main comparisons of interest are response time, and brain activation increases on incongruent as compared with congruent trials, as illustrated by the “>“ symbols separating the panels representing each trial type. The +/− and M/F symbols shown to the right of each sample screen are not shown during performance of the actual task and are included here to clearly illustrate the differences between target and flanker stimuli in each task.

Figure 2

Graph showing response times for congruent and incongruent trials for both the affective and the cognitive flanker tasks. As can be seen here, response times are significantly and equivalently slower on incongruent trials for both tasks. Inc = incongruent; Con = congruent. *Effect of incongruence significant for each task at p < .05; ns = nonsignificant interaction effect.

Figure 3

Regions showing greater conflict-related activity in the incongruent–congruent contrast for both the affective and the cognitive flanker tasks. Graphs at the left and the right show the magnitude of this activity for selected functional ROIs shown in the center panels. As can be seen in these graphs, these regions are equivalently activated (all pairwise p values = ns) during both affective and cognitive conflicts. dACC = dorsal anterior cingulate cortex; MFC = medial frontal cortex; vlPFC = ventrolateral pFC. MNI coordinates for each region are shown in parentheses.

Figure 4

Regions selectively activated for affective (left panel) or cognitive (right panel) conflicts. Comparison of left and right panels makes clear that affective and cognitive conflicts differentially depend upon medial and left lateral prefrontal systems, respectively. mPFC = medial pFC; vlPFC = ventrolateral pFC. MNI coordinates for each region are shown in parentheses.

Figure 5

Regions whose conflict-related activity differentially correlated with the magnitude of response time interference on incongruent as compared with congruent trials during the affective (right panels) or cognitive (left panels) flanker tasks. Each point represents data for a single subject, with gray/partially filled circles representing relative outliers down-weighted by the robust regression algorithm ( Wager et al., 2005) used to compute the observed relationships. Top and bottom panels show medial and ventrolateral regions whose activity differentially correlated positively with the magnitude of behavioral response conflict during either each task. These data dovetail with an extend those shown in Figure 4 by showing additional regions of rostral medial and left inferior vlPFC selectively associated with affective as compared with cognitive conflict, respectively. rCC/vmPFC = rostral cingulate/ventromedial pFC; vlPFC = ventrolateral pFC. Inc = incongruent; Con = congruent.