Hypnosis Test Participant (IMAGE) Friedrich-Schiller-Universitaet Jena Caption While under hypnosis, the test participants had to react on various symbols. In order to observe brain activity, the participants were linked up to an EEG. In this way, the psychologists were able to find out how hypnosis influences specific regions of the brain while it receives a visual stimulus. Credit Jan-Peter Kasper/FSU Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.