title: Visual control of braking in goal-directed action and sport.
abstract: Reaching a moving object, avoiding an obstacle, or controlling a rotation are common requirements of experts in sport and goal-directed action. Since the original analysis of optic flow, a large number of studies have addressed the problem of perception and control of braking. In this paper, the perception-action strategies described for deceleration control are reviewed; driving, docking, landing, somersaulting, running and reaching are analysed. The role played by 'tau dot', the first temporal derivative of tau, is shown to be critical. However, the so-called constant tau-dot strategy proposed to explain how we regulate our deceleration in such circumstances is critically examined and rejected. New directions in the problem of braking control are proposed that emphasize: (1) the advantage of tau-dot over other kinematic variables; (2) the task specificity of tau-dot; (3) the need to consider tau-dot as a control variable; and (4) the role played by the controller dynamics in the perception-action loop. Several directions for future research are suggested.
authors.affiliation: Movement and Perception Laboratory, Faculty of Sport Sciences, University of the Mediterranean, Marseille, France.
authors.forename: B G
authors.initials: BG
authors.lastname: Bardy
authors.forename: W H
authors.initials: WH
authors.lastname: Warren
mesh_terms: D000818:Animals; D001132:Arm / Q000502:physiology; D001334:Automobile Driving; D001717:Birds / Q000502:physiology; D003654:Deceleration; D005426:Flight, Animal / Q000502:physiology; D006173:Gymnastics / Q000502:physiology; D006801:Humans; D008124:Locomotion / Q000502:physiology; D009039:Motion Perception / Q000502:physiology; D009068:Movement / Q000502:physiology; D012399:Rotation; D012420:Running / Q000502:physiology; D013028:Space Perception / Q000502:physiology; D013177:Sports / Q000502:physiology*; D013647:Task Performance and Analysis; D014796:Visual Perception / Q000502:physiology*