Abstract
With respect to motor control, scientists have long assumed, on the basis of both clinical findings and neuropsychological studies, that there are interhemispheric asymmetries in the human cerebrum. The left hemisphere has been reported to be dominant for feedforward aspects of motor control as well as for speech processing. On the other hand, the right hemisphere is dominant for closed-loop motor processes, facial recognition, and attentional monitoring. The present review presents experimental evidence for interactions between the cerebral hemispheres in the bimanual control of muscle force and movement timing and bilateral transfer of perceptual-motor information for motor skill. First, the asymmetrical control of force and the symmetrical control of timing in bimanual simultaneous hand movements are discussed. Second, the entrainment of force in bimanual simultaneous hand movements with asymmetrical forces is described. Third, the author addresses the lateralization of transfer of visuomotor information between the right and left hands. During unimanual hand movements with visual feedback, whereas positive transfers from the left to the right hand were observed for right-handers, left-handers showed the opposite direction for positive transfers. Thus, because the hemispheres differ in the kinds of perceptual-motor information they most effectively encode, they complement each other.
