Motor adaptation is a form of motor learning, described as a process of acquiring and restoring movement skills. The Central nervous system adapt to environmental forces, in order to eliminate kinematic errors.
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Motor adaptation theory
Acquiring motor patterns is the most primal learning process in animal development – in evolution and maturation. The primacy of the learning process led to the development of instincts. The primary instinct in any encounter with a new environment of forces is to overcome and adjust in order to achieve results. In the process of adjustment – learning of new motor patterns is gradually achieved. Adaptation is sometimes viewed as a process in which the nervous system learns to predict and cancel effects of a novel environment, returning movements to near baseline (unperturbed) conditions. During motor adaptation the nervous system constantly uses error information to improve future movements.
After-effects
As demonstrated in the chart, when the environmental forces are removed, the subject reserves, for a limited time, the adaptive movement pattern (stage 4). This motor after-effect demonstrates that the learner does not merely react to environmental changes but also anticipates the expected dynamics of the new environment and moves according to a new set of expectations. Therefore, motor adaptation appears to rely on an update in the internal representation (internal model) of the external environment.
Internal model
The after-effects phenomena suggests that prior to the movement, the CNS generates an internal-model, a sort of internal-map that guides the body in the course of the movement, and adapt to environmental forces. This observation suggests that in programming the motor output to the muscles of the arm, the CNS uses an internal model (Wolpert et al., 1995b) to predict the mechanical dynamics of the task.