Article

Balance control can be interpreted as a combination of state feedback control
with optimal state estimation. In this framework, state estimation uses an
internal model of body and sensor dynamics to process sensory information and
determine body orientation. The aim of this study was to assess the ability of
the brain to create accurate state estimation when the congruence between sensory
information was altered. Participants stood upright on a force platform with a monitor directly in front of them at eye level displaying their center of
pressure (CP) position in real-time. When a target appeared on the monitor,
participants had to move their CP as fast and as accurately as possible within
the target. Voluntary balance pointing movements were made with the head either
straight or rotated about the trunk, and mapping directions of the CP were
changed on the basis of experimental conditions. Manipulating the sensory
information congruency caused less accurate state estimation of the body motion
leading to larger signed and absolute angular errors and a greater area of the
final CP position were measured. These results suggest that performing
head-centered to trunk-centered sensorimotor transformation reduces the accuracy
in the state estimation of body motion during a balance pointing task.
CI - Crown Copyright (c) 2013. Published by Elsevier B.V. All rights reserved.

Langue : ANGLAIS