Anterior cingulate cortex: A brain system necessary for learning to reward others?
Fig 1
Prosocial learning tasks in humans and monkeys.
(a) Example of the prosocial learning task used in humans [4]. Participants learn by trial and error which of 2 pictures is more likely to deliver a reward. One picture has a high probability of reward, and one has a low probability of a reward. On some blocks and trials, participants play for outcomes for themselves (Self), on some, they play for outcomes for another person (“Betsy” in this example), and on some trials, neither person receives the reward (no one). (b) Example of the prosocial learning task used by Basile and colleagues (2020) [15]. Monkeys learned the outcomes of 3 different cues, some cues rewarded only the monkey themselves (self), some cues rewarded the social partner (other), and some cues rewarded neither monkey (neither). Monkeys first fixated on a cue in the of the screen, and then a target appeared that they had to saccade to if they wanted to accept the offer or break fixation if they wanted to reject the offer. (c) Schematic of the results of Basile and colleagues. Before lesions to the ACC, monkeys were able to learn which cues rewarded themselves, other, or neither and showed a preference for “self over other” and “other over neither.” After ACC lesions, monkeys were able to learn with a new set of cues which cue rewarded themselves but could no longer learn to associate stimuli with other or neither. ACC, anterior cingulate cortex.