Figure 1.
Sensory ambiguity influences postural behavior.
(A) Graphical model, a compact way of describing the assumptions made by a Bayesian model. is the velocity of body motion, while
is the velocity of the environment motion.
represents a noisy estimate of the body velocity that is sensed by kinesthetic and vestibular signals.
represents the visually perceived velocity of the relative motion between the body and the environment. The attribution model estimates
from these perceived cues. (B) Distribution of body velocities during unperturbed stance averaged across subjects tested in our experiment (C) Experimental data and model fits for healthy subjects tested in our experiment.
Figure 2.
Gain of the postural response of healthy subjects and patients with vestibular loss.
(A) and (B) represent the experimental data and model fits of healthy subjects and patients tested in ref. 5 (Mergner et al. 2005). (C) and (D) represent the experimental data and model fits of healthy subjects and patients tested in ref. 4 (Peterka and Benolken 1995).
Figure 3.
Alternative models of postural control.
(A) Model that predicts constant gain of the postural response. (B) Model where amplitude of the postural response increases logarithmically with visual scene velocity and then saturates. (C) Model where the gain is initially constant and then monotonically decreases with the visual scene velocity. Here represents the visual scene velocity,
represents the true body velocity and
indicates the estimate of the body velocity calculated by the models.