感激和负债感影响受惠者回馈行为的认知神经基础：个体差异视角

Reciprocal behavior is one of the most important human prosocial behaviors. Although previous studies have focused on individuals’ positive emotions after receiving help (e.g., gratitude) and their subsequent reciprocal behaviors, little is known about individuals’ negative emotions (e.g., indebtedness) after receiving help and their influences on reciprocal behaviors. Previous studies have suggested gratitude and indebtedness as important emotional motivations behind the beneficiaries' reciprocal behaviors to the benefactors. Our previous works have shown that, the extents of the influence of gratitude and the influence of indebtedness on reciprocity vary largely across individuals. This individual difference may be closely related to various social phenomena, such as the absence of gratitude-induced reciprocity and bribery among human relationship network. The current project combines multiple research approaches and aims to investigate the neurocognitive bases underlying this individual difference from the perspectives of personality, social learning, and brain-behavior association. Our project consists of three closely connected parts. Study 1 will employ the questionnaire investigation method to reveal the association between personalities and the extents of the influences of these two emotional motivations on reciprocal behaviors. Study 2 will apply behavioral tests and functional magnetic resonance imaging (fMRI) to investigate how social learning modulates the extents of the influences of these two emotional motivations on reciprocal behaviors and the underlying neural bases. Study 3 will introduce high-definition transcranial direct current stimulation (HD-tDCS) approach to examine the causal relationship between the neural correlates and the extents of the influences of these two emotional motivations on reciprocal behaviors. The project will make significant contributions to explaining and predicting individuals’ reciprocal behaviors at the level of its underlying mechanisms.

回馈行为是人类重要的亲社会行为。虽然已有研究关注了受惠者接受帮助后的正性情绪（如感激）及后续回馈行为，但甚少关注其接受帮助后的负性情绪（如负债感）及后续行为。感激和负债感均能作为情感动机促进受惠者对施惠者的回馈行为。申请人研究发现，受惠者回馈行为在何种程度上受感激的影响、何种程度上受负债感的影响存在较大的个体差异，该个体差异与感恩缺失、人情受贿等现象密切相关。本项目综合多种研究手段，从人格特质、社会学习、脑区-行为关联等角度，系统探讨个体差异背后的认知神经基础。项目由三部分有机组成：研究一采用问卷调查，考察两种情感动机对回馈行为的影响程度与人格特质的关系；研究二采用行为和脑成像研究，考察社会学习如何改变两种情感动机对回馈行为的影响程度及其神经基础；研究三采用高精度经颅直流电刺激技术，验证种子脑区与两种情感动机对回馈行为影响程度的关联。本项目研究成果有利于在机制层面上解释和预测人类回馈行为。

回馈行为是人类重要的亲社会行为。以往研究发现，个体接受帮助后所产生的负债感包含两种成分：内疚和义务感。内疚，连同感激，产生于受助者在帮助中感受到的善意意图，并作为交往动机促进回馈行为；义务感产生于受助者对帮助者策略性意图的评价，并作为义务动机促进回馈行为。受助者回馈行为在何种程度上受交往动机的影响、何种程度上受义务动机的影响存在较大个体差异，该个体差异与感恩缺失、人情受贿等现象密切相关。本项目旨在应用多种研究手段系统探讨该个体差异背后的认知神经基础。.研究一从特质因素和发展规律等角度出发，采用问卷追踪研究和发展研究发现，受助者具有留守经历、处于抑郁状态或者童年中期内疚和义务感发展的异常，均可能会导致其回馈行为受义务动机的相对影响程度增加，进而影响其回馈偏好。.研究二从后天学习的角度出发，采用行为实验和计算建模，揭示了回馈行为的社会学习效应以及个体初始回馈偏好和被观察者身份的调节作用。个体初始回馈行为受义务动机的影响程度越大，其回馈行为因观察他人而发生的改变越多。初始回馈行为受义务动机影响低的被试在观察更具权威的人物行为后社会学习效应更强；而回馈行为受义务动机影响高的被试则无此效应。.研究三从神经机制的角度出发，通过fMRI多体素模式分析，揭示了回馈效率影响回馈行为的个体差异及其认知神经基础。当利他和策略性帮助者的回馈效率相等时，回馈决策的个体差异表征主要涉及左侧眶额皮层；当利他帮助者的回馈效率更高时，个体回馈决策中对交往动机的考虑权重增加，此个体差异表征主要涉及腹内侧前额叶；当策略性帮助者的回馈效率更高时，个体回馈决策中对义务动机的考虑权重增加，此个体差异表征主要涉背内侧前额叶。tDCS实验发现，背内侧前额叶活动的抑制削弱了意图评价对于情感动机的影响，进而影响回馈决策。.本项目研究成果有助于在机制层面上解释和预测人类回馈行为，为相关障碍的风险评估及循证矫正提供理论指导和定量化行为-大脑指标。