Brain structures related to active and passive finger movements in man

A PET study was performed in six normal volunteers to elucidate the functio nal localization of the sensory afferent component during finger movement. Brain activation during the passive movement driven by a servo-motor was co mpared with that during an auditory-cued active movement which was controll ed kinematically in the same way as the passive one. A newly developed devi ce was used for selectively activating proprioception with a minimal contri bution from tactile senses. Active movement was associated with activation of multiple areas, including the contralateral primary sensorimotor cortex, premotor cortex, supplementary motor area (SMA), bilateral secondary somat osensory areas and basal ganglia and ipsilateral cerebellum. In contrast, o nly the contralateral primary and secondary somatosensory areas were activa ted by the passive movement. It is likely that the contribution of proprioc eptive input to the activation of the premotor cortex, SMA, cerebellum and basal ganglia, if any, is small. However, the present results do not rule o ut the possibility that the cutaneous afferent input or the combination of cutaneous and proprioceptive input participates in the activation of those areas during the active movement.