Seeing the Errors You Feel Enhances Locomotor Performance but Not Learning

• Published in: Current biology Vol. 26; no. 20; pp. 2707 - 2716
• Main Authors: Roemmich, Ryan T., Long, Andrew W., Bastian, Amy J.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 24.10.2016
• Subjects: adaptation; Adult; feedback; Feedback, Sensory; Female; Gait; Humans; Learning; locomotion; Male; Motor Activity; motor learning; split-belt treadmill; Vision, Ocular; Visual Perception; Walking; Young Adult; feedback; motor learning; split-belt treadmill; gait; walking; locomotion; adaptation
• ISSN: 0960-9822; 1879-0445
• DOI: 10.1016/j.cub.2016.08.012

In human motor learning, it is thought that the more information we have about our errors, the faster we learn. Here, we show that additional error information can lead to improved motor performance without any concomitant improvement in learning. We studied split-belt treadmill walking that drives people to learn a new gait pattern using sensory prediction errors detected by proprioceptive feedback. When we also provided visual error feedback, participants acquired the new walking pattern far more rapidly and showed accelerated restoration of the normal walking pattern during washout. However, when the visual error feedback was removed during either learning or washout, errors reappeared with performance immediately returning to the level expected based on proprioceptive learning alone. These findings support a model with two mechanisms: a dual-rate adaptation process that learns invariantly from sensory prediction error detected by proprioception and a visual-feedback-dependent process that monitors learning and corrects residual errors but shows no learning itself. We show that our voluntary correction model accurately predicted behavior in multiple situations where visual feedback was used to change acquisition of new walking patterns while the underlying learning was unaffected. The computational and behavioral framework proposed here suggests that parallel learning and error correction systems allow us to rapidly satisfy task demands without necessarily committing to learning, as the relative permanence of learning may be inappropriate or inefficient when facing environments that are liable to change. •People can use visual error feedback to acquire a new walking pattern faster•Visual error feedback triggers voluntary correction of walking errors•Voluntary correction and motor adaptation work in parallel to change walking•Voluntary correction monitors adaptation; adaptation learns from prediction error People can adapt their gait using proprioception to detect errors. When they also see their errors, adaptation appears to accelerate. However, Roemmich et al. show that visual and proprioceptive error feedback drive distinct mechanisms to change walking patterns. These mechanisms work in parallel to improve human gait.