Figure 7. Hierarchical logistic regression of switching behavior in the Both condition.

(A) Behavioral data alone. Using behavioral data from the Both condition, group alignment and reward rank were used to predict when participants switched buttons. Three participants exhibited beta values more than three standard deviations from the mean beta values, and were excluded (leaving n = 112 values, arbitrary units). Beta values for group alignment were significantly less than zero across participants (p<10⁻¹⁵), indicating that, as in the Choices condition, misalignment with the group was associated with a greater probability of switching. The beta values for reward rank were only marginally different from zero (p = .07). (B) Behavioral data and insula activity. Insula activity for each choice (at time t+4 seconds, where t is the time at which a decision was submitted) was incorporated into the regression model, to test the degree to which insula activity explained switching behavior beyond that explained by group alignment and reward rank. The beta values (n = 112 values, arbitrary units) for insula activity were significantly greater than zero across participants (p<10⁻¹²), indicating that for most participants increased insula activity was associated with a greater probability of switching independent of social information of either type.