Hj. Crawford et al., EFFECTS OF HYPNOSIS ON REGIONAL CEREBRAL BLOOD-FLOW DURING ISCHEMIC PAIN WITH AND WITHOUT SUGGESTED HYPNOTIC ANALGESIA, International journal of psychophysiology, 15(3), 1993, pp. 181-195
Using Xe-133 regional cerebral blood flow (CBF) imaging, two male grou
ps having high and low hypnotic susceptibility were compared in waking
and after hypnotic induction, while at rest and while experiencing is
chemic pain to both arms under two conditions: attend to pain and sugg
ested analgesia. Differences between low and. highly-hypnotizable pers
ons were observed during air hypnosis conditions: only highly-hypnotiz
able persons showed a significant increase in overall CBF, suggesting
that hypnosis requires cognitive effort. As anticipated, ischemic pain
produced CBF increases in the somatosensory region. Of major theoreti
cal interest is a highly-significant bilateral CBF activation of the o
rbito-frontal cortex in the highly-hypnotizable group only during hypn
otic analgesia. During hypnotic analgesia, highly-hypnotizable persons
showed CBF increase over the somatosensory cortex, while law-hypnotiz
able persons showed decreases. Research is supportive of a neuropsycho
physiological model of hypnosis (Crawford, 1991; Crawford and Gruzelie
r, 1992) and suggests that hypnotic analgesia involves the supervisory
, attentional control system of the far-frontal cortex in a topographi
cally specific inhibitory feedback circuit that cooperates in the regu
lation of thalamocortical activities.