title: Visual control of braking: a test of the tau hypothesis.
abstract: Deceleration during braking could be controlled by (a) using the time derivative of the relative rate of optical expansion, relative to a -0.5 margin value of tau-dot (D.N. Lee, 1976) or (b) computing the required deceleration from spatial variables (i.e., perceived distance, velocity, or object size). Participants viewed closed-loop displays of approach to an object and regulated their deceleration with a brake. The object appeared on a checkerboard ground surface (providing velocity, distance, and size information) or with no background (providing only optical expansion). Mean tau-dot during braking was -0.51, and estimates of the critical value of tau-dot based on brake adjustments were -0.44 and -0.52, close to the expected value. There were no overall effects of the ground surface or object size. The results are consistent with a tau-dot strategy, where the direction and magnitude of brake adjustments are regulated using tau-dot.
authors.affiliation: Department of Cognitive and Linguistic Sciences, Brown University, Providence, Rhode Island 02912, USA.
authors.forename: E H
authors.initials: EH
authors.lastname: Yilmaz
authors.forename: W H
authors.initials: WH
authors.lastname: Warren
mesh_terms: D000054:Acceleration; D000328:Adult; D001334:Automobile Driving / Q000523:psychology*; D003196:Computer Graphics; D003198:Computer Simulation; D003654:Deceleration; D004215:Distance Perception; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D009039:Motion Perception; D009949:Orientation; D011597:Psychomotor Performance; D011601:Psychophysics; D011930:Reaction Time