Cerebral processing of words and the development of chronic pain

The processing of pain-related, body-related, and neutral words was assessed in individuals with prechronic pain and matched healthy controls. Integrated surface electromyogram, heart rate, skin conductance level, and visual event-related potentials from 11 electrode sites were recorded during the presentation of three word types at perception threshold. Startle responses were recorded from words presented above perception threshold. The patient and control groups did not differ in recognition performance. Pain-related words evoked an enhanced early component (N100) of the visual event-related potential only in the prechronic pain group. In both groups the late slow wave and the startle response were enhanced for body- and pain-related words compared with those for neutral words. All word types elicited larger late positivities in the prechronic pain group and in the right compared with the left hemisphere. These data suggest differential cortical processing of pain-related material in persons at a prechronic pain stage.