They
also found when the volunteers were asked to simply imagine, that they
felt the same pain, but had significantly different brain activity than
under hypnotised and physical pain conditions.
Volunteers
were chosen using the Harvard Group Scale of Hypnotic Susceptibility and
were hypnotised with a simple imagery induction such as going down stairs
or descending in a lift.
Details
of the study are published in the journal NeuroImage under the
joint authorship of Dr. David Oakley, Director of UCL's Hypnosis Unit
and Dr Stuart Derbyshire, assistant professor of anaesthesiology and radiology
at Pittsburgh University.
As part
of the study eight volunteers were placed a magnetic resonance brain scanner
and pictures of their brain function taken while they were hypnotised.
They
experienced periods of rest, periods of noxious heat delivered to the
hand and periods when they were told the heat was coming but none was
actually delivered. During this third period all the volunteers reported
still experiencing heat and most of these non-stimuli were experienced
as painful. None reported believing the probe was switched off - though
it was,
Dr.
Derbyshire explained: "Thus we were able to present images of the
brain during an experience of pain based on actual delivery of a noxious
stimulus and during a hypnotically induced experience of pain when no
stimulus was actually delivered."
He claimed
the study provided direct evidence of the brain generating pain in the
absence of any actual noxious input. "That
is significant because many functional disorders, such as fibromyalgia,
might rely upon similar mechanisms."
Dr Oakley
commented: "The fact that hypnosis was able to induce a genuine painful
experience suggests that some pain really can begin in our minds. People
reporting this type of pain are not simply imagining it."
He added:"A
lot of people have been dismissed as malingerers. But the research findings
should reassure people suffering these types of pain that they were not
imagined É You shouldn't treat the patient as if the pain is just imagined.
"If
this pain has an origin in the brain it suggests that you can use other
therapies, such as hypnosis, to alleviate the pain."
Dr Oakley
recognised though there would inevitably be cases of people making up
symptoms, for example to avoid going back to work.
He believes
studies such as this, published in reputable scientific journals, offer
evidence that hypnosis has moved "out of the Dark Ages" to become
a valuable research tool.
"Hypnosis
offers a safe way of altering a person's experience of themselves or of
the world around them," he added. |
