title: The role of haptic exploration of ground surface information in perception of overhead reachability.
abstract: The authors performed an experiment in which participants (N = 24) made judgments about maximum jump and reachability on ground surfaces with different elastic properties: sand and a trampoline. Participants performed judgments in two conditions: (a) while standing and after having recently jumped on the surface in question and (b) while standing on a third control surface, eliminating haptic exploration of the surface in question. There was a high correlation between perceived maximum reachable height and actual maximum reachable height in all conditions. Judging performance on the basis of visual and haptic exploration of ground surface information was slightly overestimated, whereas performance on the basis of visual information alone was underestimated and variable for the different surfaces. The authors discuss possible causes for the observed errors. They emphasize that there is a considerable nonvisual aspect to the nature of the information specifying affordances for overhead reach and jumping and that perceptual performance is degraded when spontaneous exploratory movement is restricted.
authors.affiliation: Center for Human Movement Sciences, University Center for Sport, Exercise and Health, and Center for Sports Medicine, University Medical Center Groningen, University of Groningen, The Netherlands. g.j.pepping@sport.umcg.nl
authors.forename: Gert-Jan
authors.initials: GJ
authors.lastname: Pepping
authors.forename: François-Xavier
authors.initials: FX
authors.lastname: Li
mesh_terms: D001132:Arm; D004215:Distance Perception / Q000502:physiology*; D004548:Elasticity; D006801:Humans; D007600:Judgment; D007699:Kinesthesis / Q000502:physiology*; D008297:Male; D009068:Movement; D011597:Psychomotor Performance / Q000502:physiology*; D012016:Reference Values; D013037:Spatial Behavior / Q000502:physiology*; D013499:Surface Properties; D014110:Touch / Q000502:physiology*; D055815:Young Adult