Consistent visuomotor adaptations and generalizations can be achieved through different rotations of robust motor modules

Humans have a remarkable ability to modify their motor commands in response to alterations in the environment. These motor commands are thought to be adaptively tuned by combining different motor primitives, a characteristic that allows for adaptations to be generalized also to relevant untrained scenarios. A complementary theory of motor primitives has shown that natural movements can be described by the combination of relatively invariant sets of muscle synergies. Synergistic structures have been shown to be maintained and tuned during motor adaptations. Here we studied the influence of synergistic organization of movement at the muscular level on the way in which adaptations to a 45{degrees} clockwise visuomotor rotation are achieved and generalized. We confirm that adaptation is achieved by tuning a set of robust muscle synergies and we show that the same biomechanical adaptation can be achieved by differentially tuning the same synergies. We demonstrate that this differential tuning ...