不反应是有待揭示的正念起效机制。最新的理论假说认为，正念培育的不反应，通过将刺激与其习惯化反应的分离，促进适应性反应。初步研究表明，正念干预过程中，不反应显著提升；并且只有不反应显著中介正念训练和情绪症状的关系。当前，不反应是否是正念起效机制，及其认知神经基础是什么，尚未揭示，有望成为研究重点。结合已有基础，申请者提出，若正念干预过程中，不反应的提升与压力缓解强相关；不反应的提升先于并且预测压力缓解；不反应的提升降低负性刺激回避倾向，增强疼痛耐受性；不反应的干预剂量增加，压力缓解效果增强；则说明不反应是正念起效的机制。为验证上述假设，本研究将以八周和短期正念训练为主要方法，采用情绪趋避任务、疼痛冷压任务、压力皮质醇等客观指标，通过功能核磁共振手段，探讨不反应和干预效果的强相关、时间优先、特定性和梯度准则，以明确不反应是正念干预起效的机制，为循证的正念干预方案完善和发展提供有效依据。

Non-reactivity might be the mechanism for the action of mindfulness, which remains to be revealed. The latest theories propose that non-reactivity cultivated by mindfulness promotes adaptive responses by dissociating the stimulus from its habitualized response. Preliminary studies have shown that during the eight-week mindfulness training, non-reactivity is significantly improved. Further studies have proved that only non-reactivity significantly mediates the relationship between mindfulness training and mood symptoms. Lately, whether non-reactivity is the mechanism of action for mindfulness and what its cognitive neural basis is, will become the focus of research hopefully. Based on the existing research foundations, the applicant proposes four hypotheses indicating that non- reactivity is the mechanism for the action of mindfulness. First, during the mindfulness training, whether the improvement of non-reactivity strongly associates with stress reduction. Second, whether the improvement of non-reactivity is prior to and predicts the reduction of stress. Third, whether the improvement of non-reactivity reduces the avoid tendency of negative stimulus and enhances pain tolerance. Four, during mindfulness training, whether increased dosages of the non-reactivity element have an incremental effect on stress reduction. In order to verify the above hypotheses, the present study will take the eight-week and short-term mindfulness training as the main strategies. Moreover, we will use objective measures such as the affective approach-avoid task, the cold-pressure task, and the pressure cortisol, combined with the functional magnetic resonance imaging method to explore evidences from multiple levels of analysis. To examine whether non-reactivity and the intervention outcomes meet the criteria of “strong correlation”, “time priority”, “specificity” and “gradient effect”, helps to clarify that whether non-reactivity is the mechanism for mindfulness intervention. Our study may have significant contributions in providing an effective basis for the improvement and development of evidence-based mindfulness intervention programs.