Cerebellar patients have intact feedback control that can be leveraged to improve reaching
Abstract
It is thought that the brain does not simply react to sensory feedback, but rather uses an internal model of the body to predict the consequences of motor commands before sensory feedback arrives. Time-delayed sensory feedback can then be used to correct for the unexpected—perturbations, motor noise, or a moving target. The cerebellum has been implicated in this predictive control process. Here we show that the feedback gain in patients with cerebellar ataxia matches that of healthy subjects, but that patients exhibit substantially more phase lag. This difference is captured by a computational model incorporating a Smith predictor in healthy subjects that is missing in patients, supporting the predictive role of the cerebellum in feedback control. Lastly, we improve cerebellar patients’ movement control by altering (phase advancing) the visual feedback they receive from their own self movement in a simplified virtual reality setup.
Data availability
All data generated or analyzed during this study will be openly on the JHU Data Archive under DOI 10.7281/T1/BCARLC.The data will be available here: https://archive.data.jhu.edu/dataverse/LIMBS
Article and author information
Author details
Funding
National Institutes of Health (HD040289)
- Amy J Bastian
- Noah J Cowan
Applied Physics Laboratory Graduate Fellowship
- Amanda M Zimmet
National Science Foundation (1825489)
- Di Cao
- Amy J Bastian
- Noah J Cowan
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Human subjects: The experimental protocol was approved by the Institutional Review Board at Johns Hopkins University School of Medicine (protocol # IRB00182673) and all participants gave informed consent prior to joining this study, according to the Declaration of Helsinki.
Reviewing Editor
- Richard B Ivry, University of California, Berkeley, United States
Publication history
- Received: November 1, 2019
- Accepted: October 6, 2020
- Accepted Manuscript published: October 7, 2020 (version 1)
- Version of Record published: October 21, 2020 (version 2)
Copyright
© 2020, Zimmet et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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