Suggested visual hallucination without hypnosis enhances activity in visual areas of the brain

• Published in: Consciousness and cognition 2012-03, Vol.21 (1), p.100-116
• Main Authors: McGeown, William J., Venneri, Annalena, Kirsch, Irving, Nocetti, Luca, Roberts, Kathrine, Foan, Lisa, Mazzoni, Giuliana
• Format: Article
• Language: English
• Subjects: Adult; Biological and medical sciences; Brain - physiology; Brain imaging; Brain Mapping; Cognition & reasoning; Color; Color Perception - physiology; Eyes & eyesight; Female; Fundamental and applied biological sciences. Psychology; Hallucinations - psychology; Humans; Hypnosis; Italy; Magnetic Resonance Imaging; Male; Medical sciences; Middle Aged; Perception; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Psychopathology. Psychiatry; Relaxation. Biofeedback. Hypnosis. Selfregulation. Meditation; Sensory perception; Suggestibility; Suggestion; Treatments; Vision
• ISSN: 1053-8100; 1090-2376
• DOI: 10.1016/j.concog.2011.10.015

► Color perception can be altered without using hypnosis as well as with hypnosis. ► Hypnosis provides a moderate but significant boost to color altering ability. ► The deeper the level of hypnosis the greater the ability to alter perception. ► The ability to be hypnotized deeply relates to more color change out of hypnosis. ► Less default mode activity in hypnosis at rest correlated with activity on the task. This functional Magnetic Resonance Imaging (fMRI) study investigated high and low suggestible people responding to two visual hallucination suggestions with and without a hypnotic induction. Participants in the study were asked to see color while looking at a grey image, and to see shades of grey while looking at a color image. High suggestible participants reported successful alterations in color perception in both tasks, both in and out of hypnosis, and showed a small benefit if hypnosis was induced. Low suggestible people could not perform the tasks successfully with or without the hypnotic induction. The fMRI results supported the self report data, and changes in brain activity were found in a number of visual areas. The results indicate that a hypnotic induction, although having the potential to enhance the ability of high suggestible people, is not necessary for the effective alteration of color perception by suggestion.