It is suggested that the nervous system learns to predict and cancel effects of a novel environment, returning movements to near baseline (unperturbed) conditions.
Animals undergoing split-belt adaptation adjust their interlimb coordination pattern to regain overall gait symmetry.
[3][4][5] 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 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.
Using optogenetics the study, done by Dr. Mackenzie Mathis at Harvard University, using mice could also show that somatosensory cortex is involved in updating the internal model.