Fig. 4.

Frequency of giving between isolated lesion groups. Proportions of ‘give’ decisions are shown for each participant group. Across all twenty trials, no differences were observed between healthy comparison (light grey), BDC (dark grey), and amygdala patients (green; all Ps >0.26). However, all three comparison groups differed significantly from the vmPFC and dlPFC patients. Results show that dlPFC damage is associated with reduced cooperation, and vmPFC damage is associated with greater cooperation. Violin plot width represents the density of the distribution for each frequency of giving (e.g. healthy comparison participants give 41% of the time more often than 100% of the time). Plot height is constrained to the range of the data for each group (e.g. amygdala patients never gave more than 90% of the time). Circles reflect mean for each lesion group. Vertical lines indicate ±1 SEM. Since the isolated vmPFC and dlPFC groups each consist of one patient, horizontal lines at the mean are used instead of error bars.