Dopamine and the precision weighting of social cues

How do we understand each other? Navigating the social world can be difficult, as social cues are often ambiguous or contradictory. So-called Bayesian inference theories claim that we use statistical information about our past experiences to increase our certainty about current events. For example, if we are meeting a friend who has been very punctual in 10 out of 10 of our last meetings, we expect with high certainty that our friend will be punctual again this time around. However, today they turn up late, which leaves us very surprised. According to Bayesian theories we will use this surprise to update our expectations about whether our friend will show up in time at future meet-ups. Recent research suggests that the neurotransmitter dopamine may influence how much we trust, or in other words, how much certainty we ascribe to, past experiences vs current events. While Bayesian inference accounts have grown increasingly popular in explaining human perception and behaviour, it is currently unclear how well we can explain social behaviour within this framework, or what specific role is played by dopamine. To explore the questions above, the current project will develop a variety of psychological experiments. A group of healthy adult participants will then perform these experiments after receiving a drug which alters their brain dopamine levels, and once again after receiving a placebo tablet (which does not affect their dopamine levels). By comparing participants performance in these experiments under drug vs. under placebo influence, we will shed light on the specific computations humans perform to understand others in social contexts, and how dopamine influences these computations. These new insights will ultimately benefit those individuals who suffer from dopamine dysfunctions and social difficulties.