Figure 5.

Regional analysis on the aMPFC distinguishes friends from strangers. A, A ROI of ∼8 mm radius was drawn around a peak in the aMPFC from the contrast self > Bush in experiment 1 (see Fig. 3). B, Parameter estimates for the ROI obtained in experiment 2 indicate that close others (friends) activate this region more than unfamiliar others (strangers), whereas the similarity manipulation produces no effect. C, D, Experiment 3 replicated the lack of similarity effect seen in experiment 2, whereas experiment 4 contained only the two extremes of the conditions (similar other, dissimilar friend) to show that the dimension of closeness, not similarity, appears to drive the response in this region. This pattern replicates the similar analysis done for the rACC (see Fig. 4). *p < 0.05; ***p < 0.001.