Where's the Floor?

ABSTRACT

Visual and balance cues concerning the relative orientation of ourselves and our environment combine to direct our steps to select a secure footing. How are visual cues used to select the best support surface? Here we show that, when exposed to tilted, rectangular rooms of various aspect ratios, subjects do not necessarily choose the surface with its normal oriented closest to the gravity-defined vertical. Rather their decision is also strongly biased by the visual area subtended by each candidate surface.