Abstract

Introduction

General Review

Conclusions

References

Discussion
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Hypnosis is effective in the relief of pain, yet we are only beginning to understand the neurophysiological processes involved in the successful reduction or elimination of conscious awareness of pain (for reviews, see Crawford, 1994a,b; Crawford & Gruzelier, 1992; Crawford, Knebel, & Vendemia, 1998). The successful inhibition of pain during hypnotic analgesia requires an ability to actively control inhibitory processing of incoming stimuli. Highly hypnotizable persons can more readily reduce or eliminate the perception of pain than can hypnotically nonresponsive persons. Our research supports the proposal that (1) hypnotic analgesia is an active inhibitory process that operates to reallocate thalamocortical activities, and (2) highly hypnotizable persons can better suppress pain because of their more effective frontal attentional and inhibitory systems. In scalp (Crawford et al., 1998a,b; under review) and intracerebrally (Kropotov, Crawford, & Polyakov, 1997) recorded somatosensory event-related potenti al (SERP) studies we demonstrate early time-locked effects in the anterior region due to early re-allocation of attention (enhanced negativity of N140 and N250) and later SERP changes (reduced P70, P200, P300) in the more posterior regions due to changes in the perception of intensity. Recent regional cerebral blood flow studies using xenon inhalation (Crawford et al., 1993) and positron emission tomography (Rainville et al., 1997; Wik et al., 1998) demonstrate significant changes in the anterior frontal cortex have been demonstrated during hypnotic analgesia.

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Presentation Number SAcrawford, h.j.0611
Keywords: pain, attention, hypnosis, evoked potentials, neuroimaging