Unperceived motor actions of the balance system interfere with the causal attribution of self-motion

Unperceived motor actions of the balance system interfere with the causal attribution of self-motion

Tisserand, Romain (University of British Columbia; Université de Poitiers; Université Tours)
Rasman, Brandon G. (Erasmus MC; University of Otago)
Omerovic, Nina (Erasmus MC)
Peters, Ryan M. (University of British Columbia; University of Calgary)
Forbes, P.A. (TU Delft Biomechanical Engineering; Erasmus MC)
Blouin, Jean Sébastien (University of British Columbia)

Biomechanical Engineering

2022

The instability of human bipedalism demands that the brain accurately senses balancing self-motion and determines whether movements originate from self-generated actions or external disturbances. Here, we challenge the longstanding notion that this process relies on a single representation of the body and world to accurately perceive postural orientation and organize motor responses to control balance self-motion. Instead, we find that the conscious sense of balance can be distorted by the corrective control of upright standing. Using psychophysics, we quantified thresholds to imposed perturbations and balance responses evoking cues of self-motion that are (in)distinguishable from corrective balance actions. When standing immobile, participants clearly perceived imposed perturbations. Conversely, when freely balancing, participants often misattributed their own corrective responses as imposed motion because their balance system had detected, integrated, and responded to the perturbation in the absence of conscious perception. Importantly, this only occurred for perturbations encoded ambiguously with balance-correcting responses and that remained below the natural variability of ongoing balancing oscillations. These findings reveal that our balance system operates on its own sensorimotor principles that can interfere with causal attribution of our actions, and that our conscious sense of balance depends critically on the source and statistics of induced and self-generated motion cues.

perception
action
standing
postural sway
balance control
psychophysics
perturbation
OA-Fund TU Delft

http://resolver.tudelft.nl/uuid:7a972596-c121-49d1-a081-a215c092bd04

https://doi.org/10.1093/pnasnexus/pgac174

2752-6542

PNAS Nexus, 1 (4), 1-13

Institutional Repository

journal article

© 2022 Romain Tisserand, Brandon G. Rasman, Nina Omerovic, Ryan M. Peters, P.A. Forbes, Jean Sébastien Blouin