Figure 4

Panel A, B: Activation associated with an equality decision in the VoI condition but with a selfless decision in the High- and Low-income conditions. The bar plots represent the percent signal change (mean ± standard error) of the peak coordinate. Stronger activation [family-wise error (FWE)-corrected p < 0.05 for multiple comparisons across the whole brain] was associated with equality rather than non-equality decisions in the VoI condition but with selfless rather than selfish decisions when participants were informed of their high- and low-income classes, respectively. The caudate nucleus (14, 10, 8): FWE-corrected p = 0.029 for multiple comparisons across the whole brain, k = 13; the dorsal anterior cingulate cortex (dACC) (4, 16, 38), FWE-corrected p = 0.006 for multiple comparisons across the whole brain, k = 116. Neural data were obtained from the contrast in which the activation evident when drawing the lottery was subtracted from that observed upon a redistributive decision. Panel C, D: Activation in the caudate nucleus and dACC was associated with the attitude to be in accordance with others. Differential activation along with affective changes was observed only when participants had higher rather than lower income than their partners. Activation was significantly stronger in both regions (p < 0.05, two-tailed t-test) when participants revealed the attitude to be in accordance with others, i.e., decreased affection after income disclosure towards their partners whom they came to favour during the game. The bar plots represent the percent signal change (mean ± standard error) of the peak coordinate. Neural data were obtained from the contrast in which the activation evident when drawing the lottery was subtracted from that observed upon a redistributive decision.