The region of the human brain where computations take place during observational learning is uncovered in research published in Nature Communications this week.
Humans can learn by observing the consequences of an action taken by another human being. Previous research has demonstrated that there are three main brain areas involved in the social and reward processes that underlie social learning: the amygdala, rostromedial prefrontal cortex, and rostral anterior cingulate cortex. However, it was not known how individual neurons in these areas responded to learning alone versus learning by watching another person.
Michael Hill and colleagues analysed single-neuron recordings from the brains of ten people playing a card game. In this game, people could draw a card from one of two decks, one of which had a high percentage of winning cards (70%), and one of which had a low percentage of winning cards (30%). People drew cards themselves and also watched other people choosing the cards from the same two decks, and so were able to learn both from their own experience and from watching others. The single-cell electrode recordings taken during this game show that although neurons in the amygdala and rostromedial prefrontal cortex respond to winning or losing, only the neurons in the rostral anterior cingulated cortex encoded these outcomes differently when people made their own choices versus watching other people make their choices.
Taken together, these results provide the first single-cell evidence for the specific role of the rostral anterior cingulate cortex in observational learning.