How Systematic Misperceptions of Space Might be Useful

Frank Durgin, Swarthmore College

It has long been suspected that the perceptual experience of space is systematically biased. Hills seem steeper than they are, and visual distances are underestimated. Theorists usually attribute these errors to perceptual failure or cognitive error. Many scientists assume that accurate/successful actions indicate the (co-)existence of an undistorted (but possibly unconscious) perceptual representation. Across dozens of experiments, we have documented that a newly-discovered systematic distortion of angular perceptual variables, such as the perceived declination of gaze, provides a quantitatively precise account of a variety of errors in the perception of locomotor space. These angular distortions are consistent with a theory of efficient coding based on principles of information theory. We emphasize that successful locomotor actions do not require an accurate perceptual representation of locomotor space. Our actions are successful insofar as they are calibrated to the systematic and stable perceptual distortions inherent in the information-maximizing coding scheme our data imply.