Getting absorbed in experimentally induced extraordinary experiences: Effects of placebo brain stimulation on agency detection.

Previous work demonstrated that placebo brain stimulation can function as an experimental tool to elicit mystical and quasi-mystical (i.e., extraordinary) experiences. However, it has not yet been investigated whether these effects result from mere sensory deprivation and individual differences in suggestibility, or whether expectancy manipulations are crucial in eliciting these effects. In this study, we showed that extraordinary experiences could be systematically manipulated by means of an expectancy manipulation using a within-subjects design, while controlling for suggestibility effects. We further observed that participants' score on the Tellegen absorption scale, an individual difference measure reflecting people's propensity to get immersed in external stimuli or mental imagery, is related to the frequency and intensity of such experiences. Finally, we investigated the relationship between extraordinary experiences and agency detection, which has been hypothesized to be associated to supernatural beliefs and experiences. The experimental induction of extraordinary experiences did not result in increased agency detection.