Figure 5.

BOLD response reflecting average participant behavior. (A) Activation in ventral striatum covaried with herd influence (peak at 6, 15, −6; p < 0.05 FDR, small volume correction; z = 3.7). This corresponds to the change in behavior as a function of human social information minus the change in behavior as a function of chimp information. (B) Correlation of first-level parameter estimates from individualized herd influence contrasts and participant herding coefficients. Ventral striatum activity covaried significantly with the subjective degree of herd influence (Pearson's r = 0.544, p = 0.024; Kendall tau = 0.356, p = 0.048). (C) Comparison of second-level parameter estimates (betas_GLM) for each social condition from the same analysis and region of activation shown in (A). (D) Adjusted BOLD time courses in right ventral striatum time-locked to the presentation of social information. The behavioral relationship is evident between 3 and 7 s after the onset of social information.