Faculty of Psychology and Neuroscience, Department of Neuropsychology & Psychopharmacology. EURON, Maastricht University, Maastricht, The Netherlands.
Hum Psychopharmacol. 2023 May;38(3):e2869. doi: 10.1002/hup.2869. Epub 2023 May 4.
Although the placebo effect is well known to affect many behaviors, the effects on cognitive performance are less well investigated.
In this study, the effects of a placebo and a nocebo manipulation on cognitive performance was investigated in healthy young participants in an unblinded between-subjects study. In addition, the participants were asked about their subjective experience in the placebo and nocebo condition.
The data suggested that the placebo condition induced the feeling of being more attentive and more motivated and the nocebo condition induced a feeling of being less attentive and alert and that they performed less well than normal. However, no placebo or nocebo effects were found on the actual performance on word learning, working memory, Tower of London task, or spatial pattern separation.
These findings further support the notion that placebo or nocebo effects are not likely to occur in young healthy volunteers. However, other studies suggest that placebo effects can be found in implicit memory tasks and in participants with memory problems. Further placebo/nocebo studies are indicated using different experimental designs and different populations in order to better understand the placebo effect on cognitive performance.
尽管安慰剂效应已广为人知，会影响许多行为，但对其认知表现的影响却知之甚少。
在这项研究中，采用非盲法、分组对照的研究方法，对健康年轻参与者进行了安慰剂和反安慰剂操作对认知表现的影响的研究。此外，要求参与者在安慰剂和反安慰剂条件下描述自己的主观体验。
数据表明，安慰剂组会产生更专注、更有动力的感觉，而反安慰剂组会产生不那么专注、警觉的感觉，且表现不如正常状态。然而，在单词学习、工作记忆、伦敦塔任务或空间模式分离等实际表现上，并未发现安慰剂或反安慰剂效应。
这些发现进一步支持了这样一种观点，即安慰剂或反安慰剂效应不太可能在年轻健康志愿者中发生。然而，其他研究表明，在隐性记忆任务和有记忆问题的参与者中，可以发现安慰剂效应。为了更好地理解安慰剂对认知表现的影响，需要采用不同的实验设计和不同的人群进行进一步的安慰剂/反安慰剂研究。
