Table 1.

Model parameters and their definitions

Model Parameters	Definition
σHP	Width of the head-in-space prior, centered at upright
βHS	Uncertainty of the vestibular signal when head is upright
αHS	Increase in uncertainty of vestibular signal with head tilt
σver	Uncertainty in the vertical cardinal axis of the upright frame
σhor	Uncertainty in the horizontal cardinal axis of the upright frame
τ	Rate of increase/decrease of σver and σhor with frame tilt
λ	Lapse rate, accounting for noninformed responses