Depth Perception in Driving: Alcohol Intoxication, Eye Movement Changes, and the Disruption of Motion Parallax

Abstract

Motion parallax, the ability to recover depth from retinal motion, is acrucial part of the visual information needed for driving. Recent work indicatesthat the perception of depth from motion parallax relies on the slow eyemovement system. It is well known that that alcohol intoxication reduces the gainof this slow eye movement system, the basis for the horizontal gaze nystagmusfield sobriety test. The current study shows that alcohol intoxication also impairsthe perception of depth from motion parallax due to its influence on the slow eyemovement system. Observer thresholds in both active and passive motion parallaxtasks are significantly increased by acute alcohol intoxication. Perhaps such afailure of motion parallax plays a role when intoxicated drivers must make quickjudgements with what could be inaccurate or missing perceptual information aboutthe location of obstacles around them.