Context-Dependent Dual Adaptation to Opposing Visuomotor Rotations

When reaching towards objects, the human central nervous system (CNS) can actively compensate for two different perturbations simultaneously (dual adaptation), though this does not simply occur upon presentation. Dual adaptation is made more difficult when the desired trajectories and targets are identical and hence do not cue the impending perturbation. In cases like this, the CNS requires contextual cues in order to predict the dynamics of the environment. Not all cues are effective at facilitating dual adaptation. In two experiments we investigated the efficacy of hand and body posture contextual cues that are intrinsic to the CNS. For the hand posture experiment, we also look at the role of extended training. We found that how people held the tool or oriented their body while reaching is sufficient for concurrently adapting separate visuomotor mappings such that over time, reach errors significantly decrease. Extended practice did not lead to further benefits though.