The helmet succeeded in generating unusual, mystical-like sensations in half of them. In 20 people, the experience was exceptionally intense, research leader David Maij from the University of Amsterdam relates. Ten people indicated afterwards that they had felt contact with some ‘ultimate reality’; seven subjects had an experience that they called ‘holy’. Others could no longer move their body, were deeply emotionated or even claimed to have had an out-of-body experience. ‘One person saw themselves partaking in the experiment from a distance’.
What they didn’t know was that the helmet was fake, nothing more than a motorcycle helmet with a few wires held together by duct tape; the participants had all fooled themselves. More commentary here.