Your hand movements in my somatosensory cortex: a visuo-kinesthetic function in human area 2.

Does viewing someone's actions activate a viewer's somatosensory cortex? We tested if visual information of limb movements activated limb sections in somatosensory areas that are normally engaged in kinesthetic processing of the limb. We showed, with functional magnetic resonance imaging in 17 right-handed healthy subjects, that passive observation of flexion-extension movements of an experimenter's right hand activated the observer's contralateral hand section of area 2 which is involved in kinesthetic processing of right hand movements. This could be interpreted as a pragmatic function of the brain that permits visual information to reach the somatosensory area, and suggests human area 2 has an association function between kinesthesia and vision.