Department of Psychiatry, Ann Arbor, Michigan, USA.
Depress Anxiety. 2013 Apr;30(4):353-61. doi: 10.1002/da.22091.
Generalized social anxiety disorder (GSAD) is characterized by excessive fear of public scrutiny and reticence in social engagement. Previous studies have probed the neural basis of GSAD often using static, noninteractive stimuli (e.g., face photographs) and have identified dysfunction in fear circuitry. We sought to investigate brain-based dysfunction in GSAD during more real-world, dynamic social interactions, focusing on the role of reward-related regions that are implicated in social decision-making.
Thirty-six healthy individuals (healthy control [HC]) and 36 individuals with GSAD underwent functional magnetic resonance imaging (fMRI) scanning while participating in a behavioral economic game ("Trust Game") involving iterative exchanges with fictive partners who acquire differential reputations for reciprocity. We investigated brain responses to reciprocation of trust in one's social partner, and how these brain responses are modulated by partner reputation for repayment.
In both HC and GSAD, receipt of reciprocity robustly engaged ventral striatum, a region implicated in reward. In HC, striatal responses to reciprocity were specific to partners who have consistently returned the investment ("cooperative partners"), and were absent for partners who lack a cooperative reputation. In GSAD, modulation of striatal responses by partner reputation was absent. Social anxiety severity predicted diminished responses to cooperative partners.
These results suggest abnormalities in GSAD in reward-related striatal mechanisms that may be important for the initiation, valuation, and maintenance of cooperative social relationships. Moreover, this study demonstrates that dynamic, interactive task paradigms derived from economics can help illuminate novel mechanisms of pathology in psychiatric illnesses in which social dysfunction is a cardinal feature.
广泛性社交焦虑障碍（GSAD）的特征是过度害怕公众审视和在社交互动中沉默寡言。先前的研究常使用静态、非互动的刺激（如人脸照片）来探究 GSAD 的神经基础，并发现了恐惧回路的功能障碍。我们试图在更真实的、动态的社会互动中研究 GSAD 中的大脑功能障碍，重点关注与社会决策相关的奖励相关区域的作用。
36 名健康个体（健康对照组[HC]）和 36 名 GSAD 患者在进行功能磁共振成像（fMRI）扫描的同时，参与了一项涉及与虚构伙伴进行迭代交流的行为经济学游戏（“信任游戏”），这些伙伴具有不同的互惠声誉。我们研究了对社交伙伴信任的回报的大脑反应，以及这些大脑反应如何受到伙伴的还款声誉的调节。
在 HC 和 GSAD 中，互惠的回报都强烈地激活了腹侧纹状体，这是一个与奖励相关的区域。在 HC 中，纹状体对互惠的反应是针对那些一直回报投资的伙伴（“合作伙伴”）的，而对于没有合作声誉的伙伴则没有。在 GSAD 中，伙伴声誉对纹状体反应的调节则不存在。社交焦虑严重程度预测了对合作伙伴的反应减弱。
这些结果表明，GSAD 中与奖励相关的纹状体机制存在异常，这可能对合作社交关系的启动、评估和维持很重要。此外，这项研究表明，源自经济学的动态、互动任务范式可以帮助阐明以社交功能障碍为主要特征的精神疾病中的新的病理机制。
