Human standing balance relies on self-motion estimates that are used by the nervous system to detect unexpected movements and enable corrective responses and adaptations in control. These estimates must accommodate for inherent delays in sensory and motor pathways. Here, we used a robotic system to simulate human standing in the anteroposterior direction about the ankles and impose sensorimotor delays into the control of balance. Imposed delays destabilized standing, but through training, participants adapted and re-learned to balance with the delays. Before training, imposed delays attenuated vestibular contributions to balance and triggered perceptions of unexpected standing motion, suggesting increased uncertainty in the internal self-motion estimates. After training, vestibular contributions partially returned to baseline levels and larger delays were needed to evoke perceptions of unexpected standing motion. Through learning, the nervous system accommodates balance sensorimotor delays by causally linking whole-body sensory feedback (initially interpreted as imposed motion) to self-generated balance motor commands.
We have created a Dataverse link for the source files needed to generate the group result figures. This can be found at https://doi.org/10.5683/SP2/IKX9ML. Source files will be published and publicly available upon acceptance for publication.
Data and code for Learning to stand with unexpected sensorimotor delaysScholars Portal Dataverse, doi:10.5683/SP2/IKX9ML.
- Brandon G Rasman
- Patrick A Forbes
- Jean-Sebastien Blouin
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Human subjects: The experimental protocol was verbally explained before the experiment and written informed consent was obtained. The experiments were approved by the University of British Columbia Human Research Ethics Committee and conformed to the Declaration of Helsinki, with the exception of registration to a database.
- Noah J Cowan, Johns Hopkins University, United States
- Received: November 22, 2020
- Accepted: August 4, 2021
- Accepted Manuscript published: August 10, 2021 (version 1)
© 2021, Rasman 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.