Department of Psychology, University of Toledo, Toledo, OH 43606-3390, USA.
J Behav Med. 2011 Jun;34(3):208-17. doi: 10.1007/s10865-010-9301-9. Epub 2010 Nov 3.
In a laboratory study we examined the hypothesis that placebo expectations enhance the initial identification of placebo-relevant sensations over placebo-irrelevant sensations. Participants (N = 102) were randomly assigned to one of three expectation groups. In the first group, participants ingested a placebo capsule and were told it was caffeine (deceptive expectation). In a second group, participants ingested a placebo capsule and were told it may be caffeine or it may be a placebo (double-blind expectation). Participants in the third group were given no expectation. All participants then tallied the placebo-relevant and placebo-irrelevant sensations they experienced during a 7-min period. Participants in the deceptive expectation group identified more placebo-relevant sensations than placebo-irrelevant sensations. No-expectation participants identified more placebo-irrelevant sensations than placebo-relevant sensations. Participants given the double-blind expectation identified an equal amount of placebo-relevant and irrelevant sensations. The amount of both placebo-relevant and placebo-irrelevant sensations detected mediated the relationship between the expectation manipulation and subsequent symptom reports. These data support the position that expectations cause placebo responding, in part, by altering how one identifies bodily sensations.
在一项实验室研究中，我们检验了这样一个假设，即安慰剂预期增强了对安慰剂相关感觉的初始识别，而不是安慰剂不相关的感觉。参与者（N=102）被随机分配到三个预期组之一。在第一组中，参与者服用安慰剂胶囊，并被告知它含有咖啡因（欺骗性预期）。在第二组中，参与者服用安慰剂胶囊，并被告知它可能含有咖啡因，也可能是安慰剂（双盲预期）。第三组参与者没有预期。然后，所有参与者都在 7 分钟内记录下他们经历的安慰剂相关和不相关的感觉。欺骗性预期组比安慰剂不相关的感觉识别出更多的安慰剂相关感觉。无预期组比安慰剂相关感觉识别出更多的安慰剂不相关感觉。给予双盲预期的参与者识别出等量的安慰剂相关和不相关的感觉。检测到的安慰剂相关和安慰剂不相关感觉的数量调节了期望操纵和随后症状报告之间的关系。这些数据支持这样一种观点，即期望通过改变人们对身体感觉的识别方式，在一定程度上引起安慰剂反应。
