Psychological aspects of components of pain.

The present study investigated the inhibitory effects of acupuncture on the separate sensory and emotional components of pain and their relation to each other. Electro-acupuncture as practiced in China was applied to the same nerve used for initiating pain, and the responses of 9 adult volunteers (5 males, 4 females) were assessed. The results indicate that (a) pain involves at least two related but different components (the sensory component and the emotional component) and (b) electro-acupuncture has a stronger inhibitory effect on the emotional component of pain. The findings provide a new outlook for the improvement of the clinical effects of acupuncture and for further study of the pain mechanism.