Contribution of sensory and motor components to motor control asymmetries: an analytical model approach

Proprioceptive and motor information contribute to movement representation; however, the equivalence of homologous contralateral information has received little attention. In a recent study using the matching paradigm we showed that upper limb position sense, based on feedback control, is asymmetric and this asymmetry could be associated with a difference in gain between left (L) and right (R) sensorimotor systems. The current results also show that movement sense is asymmetric in males and this asymmetry is dependent on handedness. It is assumed that a difference in gain between each sensorimotor system may be associated with asymmetric kinesthetic representations in cortical areas. Outcomes of models representing position and velocity control respectively suggest that velocity matching may be primarily controlled in a feed forward mode. Furthermore, compatibility between the models representing position control and velocity control also indicate that i) a difference between the L and R motor gains alone is not possible and ii) there must be a difference between the L and R sensory gains. Hence, the results strongly suggest a difference in movement representation between the two hand/hemisphere systems.