title: Intercepting free falling objects: better use Occam's razor than internalize Newton's law.
abstract: Several studies have recently provided empirical data supporting the view that gravity has been embodied in a quantitative internal model of gravity thereby permitting access to exact time-to-contact (TTC) when intercepting a free falling object. In this review, we discuss theoretical and methodological concerns with the experiments that supposedly support the assumption of a predictive and accurate model of gravity. Having done so, we then propose that only a "qualitative implicit physics knowledge" of the effects of gravity is used as an approximate pre-information that influences timing of interceptive actions in the specific case of free falling objects. Clear evidence remains to be provided to define how this knowledge is combined with optical information for on-line timing of interceptive actions.
authors: Université Paris-Sud, UPRES EA 4042, Contrôle Moteur et Perception, 91405, Orsay, France. robin.baures@u-psud.fr
authors: Robin
authors: R
authors: Baurès
authors: Nicolas
authors: N
authors: Benguigui
authors: Michel-Ange
authors: MA
authors: Amorim
authors: Isabelle Anne
authors: IA
authors: Siegler
mesh_terms: D004576:Electromyography; D006112:Gravitation; D006801:Humans; D008960:Models, Psychological; D009039:Motion Perception; D011597:Psychomotor Performance; D011601:Psychophysics; D011930:Reaction Time; D013998:Time Perception; D014584:User-Computer Interface; D014796:Visual Perception