疼痛调节奖赏的认知和神经机制

Pain is found to modulate cognition and emotion in humans. Specifically, acute pain promotes reinforcement learning and induces risk-taking behavior; whereas chronic pain patients are vulnerable to negative emotions such as anxiety and depression. However, it is not clear about how pain result in these cognitive bias and affective disorders. We propose that the modulations of pain on motivation and reward neural circuitry are crucial to the consequences of pain. By combining behavioral measurements with functional magnetic resonance imaging technique, we plan to investigate the modulation of pain on reward in three studies. Study one is to investigate the cognitive mechanisms of pain effects on reward. It is hypothesized that acute pain promotes the motivation of pursuing incentives and lead individual to self-interest behaviors. Study two is to investigate the neural mechanisms of pain effects on reward. It is hypothesized that acute pain facilitates reward neural circuitry, e.g., enhancing neural responses to reward experience and/or to reward anticipation. Study three aims to assess possible differences between the modulations of acute pain and chronic pain on reward neural circuitry. We hypothesize that the reward neural circuitry will be habituated or inactivated under long term chronic pain, which will lead to typical depressive symptoms like anhedonia. Our interdisciplinary approach to study the influences of pain on reward will uncover the mechanisms of how pain modulates human cognition and emotion, as well as of how acute pain transforms to chronic disease. It may also provide rational strategies for the diagnosis and intervention of chronic pain in clinic.

疼痛影响人的认知和情感，具体表现为急性疼痛促进强化学习，诱发冒险行为；慢性痛患者容易引发焦虑、抑郁情绪。然而，疼痛如何引起这些认知偏向和情感障碍的机制并不清楚。我们认为，疼痛对奖赏动机及其脑网络的调节可能是其重要内在机制。因此，本项目融合行为测量、功能磁共振成像等手段，分三个部分研究疼痛对奖赏的调节作用。研究一考察疼痛调节奖赏的认知机制，假设急性疼痛增强个体追求奖赏的动机，促使个体做出利己行为。研究二考察疼痛调节奖赏的神经机制，假设急性疼痛易化奖赏脑网络，增强个体对奖赏刺激或奖赏预期的神经响应。研究三考察急、慢性疼痛对奖赏脑网络影响的异同，假设慢性疼痛使奖赏脑网络钝化，由此导致愉悦感缺乏等典型抑郁症状。多学科交叉地研究疼痛对奖赏的调节作用，将揭示疼痛影响人类认知和情感，并演变为慢性病的可能机制；并为临床上对疼痛病症诊断和康复测评提供科学依据。

本项目聚焦疼痛对奖赏的调节作用，揭示疼痛调节奖赏与奖赏学习的认知和神经机制，已发表三项主要研究成果。.先前研究表明，疼痛影响人的认知、情感和社会行为。然而，疼痛如何引起这些认知与行为的机制并不清楚。我们认为，疼痛对奖赏追求动机及其脑网络的调节可能是其重要内在机制。因此，本项目融合行为测量、功能磁共振成像、功能近红外成像等手段，分三个部分研究疼痛对奖赏的调节作用。研究一探究疼痛影响个体追求奖赏的动机和行为表现，研究二探究疼痛影响奖赏刺激引发的脑活动，研究三探究疼痛促进合作行为中奖赏学习的多脑协同机制。.基于实验与数据分析，得到了研究成果。成果一表明急性疼痛增强个体追求奖赏的动机，促使个体做出利己行为，揭示了疼痛调节奖赏的认知机制（Wang et al., 2018, European Journal of Pain）。成果二表明急性疼痛易化奖赏脑网络，增强个体对奖赏刺激或奖赏预期的神经响应，揭示了疼痛调节奖赏的神经机制（Wang et al., 2019b, Human Brain Mapping）。成果三从奖赏动机的角度表明疼痛促进双人同步按键任务这一社会互动中的奖赏学习过程，揭示了疼痛促进奖赏学习的多脑同步机制（Wang et al., 2019a, Human Brain Mapping）。.多手段、多角度地研究疼痛对奖赏的调节作用，为阐明疼痛影响人类认知、情感和社会行为提供了一种可能的疼痛-奖赏理论。研究结果加深了我们对疼痛的认知神经机制的理解，也推进了对疼痛的社会性维度的认识。后续研究将进一步聚焦大脑奖赏系统在疼痛慢性化过程中的可能机制。