Goal Activation, Expectations, and Placebo Analgesia

描述（由申请人提供）：大量的研究表明，安慰剂可以有很强的镇痛作用。尽管大量的研究将安慰剂作为实验对照，但直到最近，对安慰剂镇痛机制的实证研究相对较少。研究安慰剂镇痛机制的研究几乎完全集中在经典条件反射和期望作为偶然机制。第三个可能导致安慰剂镇痛的因素，动机，几乎没有受到关注。基于自动加工和无意识目标激活的社会认知文献，我们开发了一个安慰剂反应模型，该模型将动机作为因果变量，使我们能够更容易地辨别安慰剂何时以及如何产生镇痛效果。该模型提出，当个体持有一个可以通过确认安慰剂期望来实现的目标时，安慰剂效应最有可能发生。三个实验提出，以证明目标和安慰剂预期相互作用，导致安慰剂镇痛。在每个实验中，安慰剂预期和目标都会被操纵。该提案的一个独特之处在于我们将研究无意识的目标。无意识目标在确定目标对安慰剂镇痛的贡献方面特别有用，因为这些目标不太可能与期望和情绪变化等因素相混淆。为了进一步检验目标改变安慰剂镇痛的假设，我们还将检验研究结果是否显示了目标的两个主要品质。最后，我们还将测量对疼痛刺激的生理反应，作为拟议效应的潜在中介。有大量证据表明，治疗急性和慢性疼痛往往受益于强大的安慰剂镇痛效果。然而，对于安慰剂镇痛如何以及何时发生尚无共识。在三个实验中，将采用理论驱动的方法来确定一个人当前的动机如何以及何时改变安慰剂镇痛。更好地理解动机在安慰剂反应中的作用对未来的临床试验以及正在进行的减轻慢性和急性疼痛的努力具有重要意义。

DESCRIPTION (provided by applicant): A great deal of research indicates that placebos can have strong analgesic effects. Despite the large number of studies incorporating placebo as experimental controls, until recently, there have been relatively few empirical investigations into the mechanisms responsible for placebo analgesia. The research that has examined the mechanisms underlying placebo analgesia has focused almost solely on classical conditioning and expectations as the casual mechanisms. A third factor that may contribute to placebo analgesia, motivation, has received virtually no attention. Based on the social-cognitive literature on automatic processing and nonconscious goal activation, we have developed a model of placebo responding which incorporates motivation as a causal variable and should enable us to discern more readily when and how placebos will have analgesic effects. The model proposes that placebo effects are most likely to occur when individuals hold a goal that can be fulfilled by confirming a placebo expectation. Three experiments are proposed to demonstrate that goals and placebo expectancies interact in causing placebo analgesia. In each experiment both placebo expectations and goals will be manipulated. A unique feature of the proposal is that we will examine nonconscious goals. Nonconscious goals are particularly useful in determining the contribution of goals to placebo analgesia as these goals are unlikely to be confounded with factors such as changes in expectancies and moods. To further test of our hypothesis that goals alter placebo analgesia, we will also test whether the findings display two primary qualities of goal. Finally, we will also measure physiological reactions to the pain stimulus as a potential mediator of the proposed effects. There is substantial evidence that treatments for acute and chronic pain often benefit from powerful placebo analgesic effects. There is no consensus, however, on how and when placebo analgesia occurs. In three experiments, a theory-driven approach will be taken to determine how and when one's current motives alter placebo analgesia. A better understanding the role of motivation in placebo responding has important implications for future clinical trials as well as ongoing efforts to alleviate chronic and acute pain.