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Serotonin, Reciprocity and the Social Brain| old_uid | 10541 |
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| title | Serotonin, Reciprocity and the Social Brain |
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| start_date | 2011/12/09 |
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| schedule | 16h-17h30 |
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| online | no |
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| location_info | 1er étage, salle de réunion 1.013 |
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| summary | Humans are selfish, but also care about the welfare of others. Counter to the predictions of influential economic models, humans often act against their own self-interest, incurring personal costs to help cooperators and punish cheaters. These so-called ‘reciprocal’ behaviours are highly variable, both between individuals and across situations, and the mechanisms that drive this variability are not well understood. One potential mechanism governing the context-dependent variability of reciprocity is neuromodulation by the neurotransmitter serotonin (5-HT), which responds to environmental stressors and shapes activity in brain regions implicated in social decision-making. Supporting this hypothesis, decades of research have linked 5-HT to prosocial behaviour across species; however, the specific motivational processes mediating this relationship have not yet been elucidated. Here, I present a series of studies designed to examine the influence of 5-HT on negative reciprocity. Our first experiment indicated that temporarily lowering 5-HT function increases the occurrence of negative reciprocity. In a second study, we showed that enhancing 5-HT function decreases the occurrence of negative reciprocity specifically through effects on harm aversion. Finally, a third study demonstrated that 5-HT depletion reduced the response of the ventral striatum to fairness, while simultaneously enhancing the response of the dorsal striatum to punishing unfairness, suggesting that changes in 5-HT neurotransmission mediate tradeoffs between the rewards of cooperation and the satisfaction of revenge. Overall, these findings provide strong evidence implicating 5-HT in human reciprocal behaviour, and begin to clarify the influence of interacting neuromodulatory systems on social decision-making. |
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| responsibles | San-Galli |
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