Institute of Psychology, Social and Affective Neuroscience, University of Basel, Basel, Switzerland,
Psychopharmacology (Berl). 2014 Jan;231(1):135-41. doi: 10.1007/s00213-013-3210-x. Epub 2013 Jul 31.
People often face decisions that pit self-interested behavior aimed at maximizing personal reward against normative behavior such as acting cooperatively, which benefits others. The threat of social sanctions for defying the fairness norm prevents people from behaving overly selfish. Thus, normative behavior is influenced by both seeking rewards and avoiding punishment. However, the neurochemical processes mediating the impact of these influences remain unknown. Several lines of evidence link the dopaminergic system to reward and punishment processing, respectively, but this evidence stems from studies in non-social contexts.
The present study investigates dopaminergic drug effects on individuals' reward seeking and punishment avoidance in social interaction.
Two-hundred one healthy male participants were randomly assigned to receive 300 mg of L-3,4-dihydroxyphenylalanine (L-DOPA) or a placebo before playing an economic bargaining game. This game involved two conditions, one in which unfair behavior could be punished and one in which unfair behavior could not be punished.
In the absence of punishment threats, L-DOPA administration led to more selfish behavior, likely mediated through an increase in reward seeking. In contrast, L-DOPA administration had no significant effect on behavior when faced with punishment threats.
The results of this study broaden the role of the dopaminergic system in reward seeking to human social interactions. We could show that even a single dose of a dopaminergic drug may bring selfish behavior to the fore, which in turn may shed new light on potential causal relationships between the dopaminergic system and norm abiding behaviors in certain clinical subpopulations.
人们经常面临这样的决策，即需要在以最大化个人回报为目的的自利行为与合作行为等规范行为之间做出选择，而后者有利于他人。对违反公平规范的社会制裁的威胁阻止了人们表现得过于自私。因此，规范行为受到寻求奖励和避免惩罚的影响。然而，介导这些影响的神经化学过程尚不清楚。有几条证据分别将多巴胺能系统与奖励和惩罚处理联系起来，但这些证据来自非社会背景下的研究。
本研究调查了多巴胺能药物对个体在社会互动中寻求奖励和避免惩罚的影响。
201 名健康男性参与者被随机分配在接受 300 毫克 L-3,4-二羟基苯丙氨酸（L-DOPA）或安慰剂之前玩经济讨价还价游戏。这个游戏有两种情况，一种是不公平的行为可以被惩罚，另一种是不公平的行为不能被惩罚。
在没有惩罚威胁的情况下，L-DOPA 的给药导致了更自私的行为，这可能是通过增加对奖励的追求来介导的。相比之下，当面临惩罚威胁时，L-DOPA 的给药对行为没有显著影响。
这项研究拓宽了多巴胺能系统在人类社会互动中对奖励寻求的作用。我们可以证明，即使是单次剂量的多巴胺能药物也可能使自私行为显现出来，这反过来可能为多巴胺能系统与某些临床亚群中遵守规范行为之间的潜在因果关系提供新的线索。
