Hypnosis And Neuroimaging :
Neuroimaging refers to a technique of examining which areas of the brain are active at any one time and can tell us something about how hypnosis works it involves the use of very expensive equipment which can display images of brain activity when the brain is involved with various tasks. I will start off by looking at neuroimaging in relation to the brain’s experience of pain.
NEUROIMAGING AND THE EXPERIENCE OF PAIN:
A study by Rainville et al (1997), using a brain imaging technique, showed that when a HYPNOTIZED subject was given the HYPNOTIC SUGGESTION THAT HE WOULD EXPERIENCE PAIN (ie he wasn’t exposed to a real painful stimulus), the degree of activity in a brain regions associated with the experience of real pain (SOMATOSENSORY CORTICAL AREAS) could be increased and decreased by the experimenter making the suggestions that the subject was experiencing more or less pain respectively.
Another study, by Derbyshire et al (2004), again using NEUROIMAGING, found that subjects given the hypnotic suggestion that they were experiencing pain showed a similar response in brain acivity. However, those subjects merely instructed to IMAGINE PAIN (WITHOUT HYPNOSIS) did NOT display the activity.
These studies suggest that, under hypnosis, without the application of a real painful stimulus, subjects can be caused to experience pain by the hypnotic suggestion that they will experience it. It seems, too, hypnosis is having a real effect, as merely telling the subject to imagine pain (without use of hypnosis, does not have the same effect).
It seems as if, according to such studies, effects of hypnotic suggestion are GENUINE, not only at the subjective level, but also in as far as they have been shown to EFFECT BRAIN FUNCTION IN A MANNER WHICH SHOWS UP VIA NEUROIMAGING: it appears that hypnotically suggested experiences CAN CAUSE SIMILAR BRAIN ACTIVITY PATTERNS TO THOSE WHICH WOULD BE CAUSED IF THE EXPERIENCE WERE REAL.
If hypnotically suggested experiences have a similar effect on the brain as real ones, there follow implications for treatment of conditions that make use of exposure therapy, such as phobias (ie the person suffering from the phobia could be given the hypnotic suggestion that s/he was exposed to the feared object as part of the DESENSITIZATION PROCESS; that is, getting used to the object feared so that the fear it induces gradually diminishes over time.
A caveat, however, is that studies of brain imaging in relation to hypnosis have not given consistent results; more studies into this area of research need to be conducted.
NEUROIMAGING, HYPNOSIS AND MOOD:
Marquet et al (1999), using a neuroimaging technique, discovered that subjects given the instruction, under hypnosis, to re-experience pleasant memories from their own lives showed significantly more activation in related brain regions (eg the PREFRONTAL CORTEX and OCCIPITAL LOBE) than when they they were merely instructed to imagine the same events (not under hypnosis); again, this suggests that the HYPNOTIC EFFECT IS A REAL ONE, with real, OBSERVERABLE effects on brain activity. Again, however, a lot more research needs to be conducted in order to clarify the relationship between hypnosis and its effect upon brain activity.
David Hosier BSc Hons; MSc; PGDE(FAHE).