Institute of Neuroradiology, University of Lübeck, Neuroimage Nord (NIN), Germany.
Eur J Pain. 2012 Apr;16(4):496-508. doi: 10.1016/j.ejpain.2011.07.010.
Perceived control over pain can attenuate pain perception by mechanisms of endogenous pain control and emotional reappraisal irrespective of whether this control is exerted or only perceived. Self-initiated termination of pain elicits different expectations of subsequent pain relief as compared to perceived pain control. It is unknown whether and how this perceived vs. exerted control on pain differs and affects subsequent pain relief. Using fMRI, we studied two factors of pain control on pain relief: the (i) sense of control (perceived control but no execution) and (ii) the execution of control (exerted control). To account for the impact of factual execution of pain control on pain relief we applied bearable short and hardly bearable long contact-heat stimuli which were applied either controllable or not. Using controllability as factor, there was dissociable neural activity during pain relief: following the perceived control condition neural activity was found in the orbitofrontal and mediofrontal cortex and, following the exerted control condition, in the anterolateral and dorsolateral prefrontal cortex and posterior parietal cortex. We conclude that (i) pain controllability has an impact on pain relief and (ii) the prefrontal cortex shows dissociable neural activity during pain relief following exerted vs. perceived pain control. This might reflect the higher grade of uncertainty during pain relief following perceived pain control mediated by the orbitofrontal and medial prefrontal cortex and processes of working memory and updating expectations during pain relief following exerted control mediated by the lateral prefrontal cortex.
对疼痛的控制感知可以通过内源性疼痛控制和情绪重新评估的机制来减轻疼痛感知，而不管这种控制是施加的还是仅仅被感知到的。与感知到的疼痛控制相比，自我引发的疼痛终止会引发对后续疼痛缓解的不同期望。目前尚不清楚这种对疼痛的感知控制与施加控制是否存在差异，以及它们如何影响后续的疼痛缓解。我们使用 fMRI 研究了疼痛控制缓解疼痛的两个因素：（i）控制感（感知控制但未执行）和（ii）控制的执行（施加控制）。为了考虑到实际执行疼痛控制对疼痛缓解的影响，我们应用了可承受的短时间和难以承受的长时间接触热刺激，这些刺激可以是可控的或不可控的。使用可控性作为因素，在疼痛缓解期间有可分离的神经活动：在感知控制条件下，眶额和中额皮质中发现了神经活动，而在施加控制条件下，前外侧和背外侧前额皮质以及后顶叶皮质中发现了神经活动。我们得出结论：（i）疼痛可控性对疼痛缓解有影响，（ii）前额叶皮质在施加和感知疼痛控制缓解疼痛时表现出可分离的神经活动。这可能反映了在感知到的疼痛控制缓解期间，由于眶额和内侧前额皮质介导的不确定性更高，以及在施加控制缓解期间由外侧前额皮质介导的工作记忆和更新期望的过程。
