The Role of Vestibular Perception in Learning a Novel Locomotor Task

Healthy locomotion is characterized by an optimal level of movement. A walking pattern needs to be stable enough to be performed relatively effortlessly, yet have enough variation to allow for adaptation to environmental changes. Learning new movements is characterized by such variation that allows greater exploration of the environment till a stable movement pattern with low variation emerges. Locomotor adaptation requires input from the visual, somatosensory and vestibular systems. During locomotion, vestibular input gives the perception of walking in a straight line. Disrupting this system causes instabilities during locomotion. Increases in variability will stimulate errors during treadmill adaptation, which may lead to improvements in learning a new task and retaining the learned movement strategies after the training is completed. During this project, 18 subjects walked on a split-belt treadmill which drove one leg significantly faster than the other, with (n=9) or without (n=9) mastoid vibration. The vibration was expected to cause instabilities in locomotion through vestibular perturbation. Limb excursion, step length, and double stance time were then analyzed specifically for variability measures. Step length showed a variation between right and left leg while learning a new task, however, vestibular stimulation did not disrupt the learning of the split belt adaptation task. Multisensory integration allowed other sensory systems (vision and somatosensory) to improve their gain and recalibrate sensorimotor organization to allow motor learning to proceed without disruption