Salient findings: summaries of key findings in the research literature.

There is considerable evidence now that many regions of the cerebral cortex are activated by pain, and that if we are to understand the exceedingly complex phenomenon of pain we must examine the contributions of each of these areas. This study attempted to locate the cortical structures associated with the suffering (as distinct from the sensory) component of the pain experience. Positron emission tomography (PET) scans were conducted during conditions of alert control, hypnosis control, and hypnotic suggestion for increased unpleasantness and decreased unpleasantness. Tracking regional cerebral blood flow across these conditions revealed that perceived suffering was associated with activation levels within the anterior cingulate cortex (ACC). Hypnotic suggestions for reduced suffering were associated with reduced activation in the ACC. Furthermore, subject ratings of reductions in suffering were linked to reductions in ACC activity, r = .42, p < .005. The results demonstrate that shifts in pain-related activity in ACC parallel selective changes in perceived unpleasantness of painful stimuli. There now appears to be direct evidence linking frontal-lobe limbic activity with pain affect, thereby supporting previous clinical lesion studies. Thus, this research supports the notion that the anterior cingulate gyrus is involved in pain and emotions. In turn, the findings may explain where and how hypnotic analgesia can sometimes secure dramatic relief for those suffering from pain.