Dissociable Effects of Serotonin and Dopamine on the Valuation of Harm in Moral Decision Making.

Dissociable Effects of Serotonin and Dopamine on the Valuation of Harm in Moral Decision Making. Curr Biol. 2015 Jul 1; Authors: Crockett MJ, Siegel JZ, Kurth-Nelson Z, Ousdal OT, Story G, Frieband C, Grosse-Rueskamp JM, Dayan P, Dolan RJ Abstract An aversion to harming others is a core component of human morality and is disturbed in antisocial behavior [1-4]. Deficient harm aversion may underlie instrumental and reactive aggression, which both feature in psychopathy [5]. Past work has highlighted monoaminergic influences on aggression [6-11], but a mechanistic account of how monoamines regulate antisocial motives remains elusive. We previously observed that most people show a greater aversion to inflicting pain on others than themselves [12]. Here, we investigated whether this hyperaltruistic disposition is susceptible to monoaminergic control. We observed dissociable effects of the serotonin reuptake inhibitor citalopram and the dopamine precursor levodopa on decisions to inflict pain on oneself and others for financial gain. Computational models of choice behavior showed that citalopram increased harm aversion for both self and others, while levodopa reduced hyperaltruism. The effects of citalopram were stronger than those of levodopa. Crucially, neither drug influenced the physical perception of pain or other components of choice such as motor impulsivity or loss aversion [13, 14], suggesting a direct and specific influence of se...
Source: Current Biology - Category: Biology Authors: Tags: Curr Biol Source Type: research