Department of Psychology, New York University, 6 Washington Place, New York, NY 10003, United States.
Neurosci Lett. 2012 Jun 29;520(2):140-8. doi: 10.1016/j.neulet.2012.03.039. Epub 2012 Mar 21.
Pain is highly modifiable by psychological factors, including expectations. However, pain is a complex phenomenon, and expectations may work by influencing any number of processes that underlie the construction of pain. Neuroimaging has begun to provide a window into these brain processes, and how expectations influence them. In this article, we review findings regarding expectancy effects on brain markers of nociception and how expectations lead to changes in subjective pain. We address both expectations about treatments (placebo analgesia and nocebo effects) and expectations about the environment (e.g. expectations about pain itself). The body of work reviewed indicates that expectancies shape pain-intensity processing in the central nervous system, with strong effects on nociceptive portions of insula, cingulate and thalamus. Expectancy effects on subjective experience are driven by responses in these regions as well as regions less reliably activated by changes in noxious input, including the dorsolateral prefrontal cortex and the orbitofrontal cortex. Thus, multiple systems are likely to interact and mediate the pain-modulatory effects of expectancies. Finally, we address open questions regarding the psychological processes likely to play an intervening role in expectancy effects on pain.
疼痛可以通过心理因素高度调节，包括期望。然而，疼痛是一种复杂的现象，期望可能通过影响构成疼痛的任何数量的过程起作用。神经影像学开始为这些大脑过程以及期望如何影响它们提供了一个窗口。在本文中，我们回顾了关于期望对伤害感受的大脑标志物的影响的发现，以及期望如何导致主观疼痛的变化。我们既涉及到对治疗方法的期望（安慰剂镇痛和反安慰剂效应），也涉及到对环境的期望（例如对疼痛本身的期望）。综述的工作表明，期望在中枢神经系统中塑造疼痛强度处理，对岛叶、扣带回和丘脑的伤害感受部分有强烈影响。期望对主观体验的影响是由这些区域以及对伤害性输入变化不太可靠地激活的区域的反应驱动的，包括背外侧前额叶皮层和眶额皮层。因此，多个系统可能相互作用并介导期望对疼痛的调节作用。最后，我们讨论了关于可能在期望对疼痛的影响中起中介作用的心理过程的开放性问题。
