Contingent Negative Variation in the Parasylvian Cortex Increases During Expectancy of Painful Sensorimotor Events: A Magnetoencephalographic Study.

Previous evidence relating to somatosensory-evoked magnetic fields has shown that the human parasylvian cortex (PC) is affected by ongoing painful sensorimotor interactions. In the present magnetoencephalographic study, the activity of the PC was investigated to evaluate the hypothesis of anticipatory processes preceding painful sensorimotor interactions. Sensorimotor interactions were induced by warned painful electrical stimulations at the left hand concomitant with a motor task of the right hand. The anticipatory activity of the PC was probed via contingent negative variation. Compared with the control nonpainful condition, the anticipation of the painful sensorimotor interactions increased the PC activity over the hemisphere ipsilateral to the stimulation. Dipole modeling indicated that the center of gravity of the anticipatory activity in the PC was located in the secondary somatosensory cortex. These results suggest that anticipation of painful sensorimotor interactions engages the human PC, especially in the hemisphere ipsilateral to upcoming painful stimuli and contralateral to preparatory motor commands. [ABSTRACT FROM AUTHOR]