Figure 4.

dACC neurons signal task conflict. A) Population average PSTH shows differences in the population response to distractors in different locations. B) Distractor location effect sizes. Top panel: Several individual neurons encoded distractor congruency (different responses to congruent and incongruent distractors, 18 cells, in red). However, the sign of these effects was heterogeneous within the congruency-selective population (mean, red arrow) and across the whole population (mean, gray arrow), indicating that action conflict did not increase dACC firing rate. Bottom panel: Task conflict signals. Same as in top panel, but for congruent and incongruent versus neutral. Significant neurons selectively increased firing rate for both incongruent and congruent distractors, which induced task conflict, compared to neutral distractors, which did not affect task performance (Wilcoxon sign-rank, p < 0.05). C) Histogram of response latencies to task distractors. Latencies were heterogeneous across the population of responsive cells, apart from one population of early-responsive cells in green. D) Early-responding cells encoded task conflict. Left: social distractors, which had a greater impact on response time than nonsocial distractors, elicited more activity in these neurons than did nonsocial distractors (p < 0.04, z(15) = 2. 12). Right: Activity was enhanced following both incongruent and congruent distractors compared to neutral distractors (p < 0.001, Wilcoxon signed rank, z(15) = 3.31), indicating that early-responding neurons signaled task conflict. No effect of distractor congruence (action conflict) was observed in these cells (p > 0.6, z(15) = 0.46).