School of Physical Education, Sport, and Exercise Sciences, University of Otago, Dunedin, New Zealand; Department of Neuroscience, Erasmus MC, University Medical Center Rotterdam, Rotterdam, Netherlands; School of Kinesiology, University of British Columbia, Vancouver, Canada
Department of Neuroscience, Erasmus MC, University Medical Center Rotterdam, Rotterdam, Netherlands
Ryan M Peters
School of Kinesiology, University of British Columbia, Vancouver, Canada; Faculty of Kinesiology, University of Calgary, Calgary, Canada; Hotchkiss Brain Institute, Calgary, Canada
Oscar Ortiz
School of Kinesiology, University of British Columbia, Vancouver, Canada; Faculty of Kinesiology, University of New Brunswick, Fredericton, Canada
Ian Franks
School of Kinesiology, University of British Columbia, Vancouver, Canada
J Timothy Inglis
School of Kinesiology, University of British Columbia, Vancouver, Canada; Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
Romeo Chua
School of Kinesiology, University of British Columbia, Vancouver, Canada
School of Kinesiology, University of British Columbia, Vancouver, Canada; Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada; Institute for Computing, Information and Cognitive Systems, University of British Columbia, Vancouver, Canada
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 about the ankles in the anteroposterior direction 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.
