What evidence have researchers found to suggest that hypnosis can produce changes in neural activity that are consistent with an altered state of consciousness? Areas involved in memory formation show decreased levels of activity when someone is led by a hypnotist to relive an incident from his or her past. Areas of the brain that process color can be activated through hypnotic suggestion, even if someone is looking at a grey picture. Areas that regulate emotional functioning show decreased activity after a person receives a course of hypnosis therapy, compared to pretreatment levels.