Behavioral and electrophysiological responses to fairness norm violations in antisocial offenders

Abstract

Antisocial personality disorder is characterized by a stable, lifelong pattern of disregard for and violation of others' rights. Disruptions in the representation of fairness norms may represent a key mechanism in the development and maintenance of this disorder. Here, we investigated fairness norm considerations and reactions to their violations. To examine electrophysiological correlates, we assessed the medial frontal negativity (MFN), an event-related potential previously linked to violations of social expectancy and norms. Incarcerated antisocial violent offenders (AVOs, n = 25) and healthy controls (CTLs, n = 24) acted as proposers in the dictator game (DG) and ultimatum game (UG) and received fair vs. unfair UG offers from either another human (social context) or a computer (non-social context). Results showed that AVOs made lower offers in the DG but not the UG, indicating more rational and strategic behavior. Most importantly, when acting as recipients in the UG, acceptance rates were modulated by social context in CTLs, while AVOs generally accepted more offers. Correspondingly, ERP data indicated pronounced MFN amplitudes following human offers in CTLs, whereas MFN amplitudes in AVOs were generally reduced. The current data suggest intact fairness norm representations but altered reactions to their violation in antisocial personality disorder.

Electrophysiological Markers of Fairness and Selfishness Revealed by a Combination of Dictator and Ultimatum Games

“…These results support the hypothesis that in UG the MFN amplitude of Responders is likely to be associated with the expectation of fairness on the part of the Proposers. Thus, the perception of the offers by the Responders —all participants of this study played the role of Responders— depended on the behavioral group, and not on the absolute value of the endowment share [47,52,114,125].…”

“…The MFN is a wave component that has been observed in association with some assessment of fairness [44][45][46][47], social status and altruistic bias [40,51,52,114], but only one study has reported quantitative ERP results in Allocators during DG [47]. However, these studies did not clearly distinguish between behavioral groups.…”

“…The lesser fair the offers in UG the larger the amplitude of the elicited MFN [32,34,37,49] and the longer its peak latency at parietal level in the Proposers receiving the feedback information [50]. In DG, MFN is associated with disadvantageous inequitable offers [47], but it is also dependent on the recipients’ social status and altruistic tendency [40,51,52]. In Responders playing UG, a positive wave (P300) peaked in the interval 300-600 at centro-parietal electrode sites in association with outcome evaluation [53,54].…”

Moral judgment modulates fairness consideration in the early outcome evaluation stage

“…结果 发现, 个体并不是按照利益最大化的理性原则提出分 配方案, 提议者往往会将一半左右的金额分配给对方, 而响应者通常会拒绝少于总金额中20%的提议 [9,13] . 进 一步研究发现, 响应者的公平决策受到社会情境的影 响, 如个体明确知道自己在与电脑进行博弈时, 对不公 平 提 议 的 拒 绝 率 显 著 低 于 与 真 实 人 类 进 行 的 博 弈 [11,14,15] . 因此, 研究者认为, 在UG中响应者拒绝不公 平提议反映了个体在社会决策情境下的公平偏好.…”

“…使用高时间分辨率的事件相关电位技术(event-related potential, ERP)研究UG任务中大脑对不同提议类 型的时间进程, 发现反馈相关负波(feedback-related negativity, FRN)和P300成分反映了个体对提议公平性的 不同评价阶段 [14,16,17] . [18,22] .…”