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|Title:||Visual Perception of Biological Motion|
|Author(s):||Scully, Deirdre Maire|
|Doctoral Committee Chair(s):||Newell, Karl M.|
|Department / Program:||Kinesiology|
|Degree Granting Institution:||University of Illinois at Urbana-Champaign|
|Abstract:||This dissertation explored recent theoretical propositions for linking theories of visual perception and action. Two experiments were conducted to examine the roles played by relative and absolute motion components in the visual pick-up of information about activity identification and speed estimation. A human performer produced 7 actions ranging from overarm throwing to overarm bowling, at 5 different speeds. A Selspot System recorded actual movement parameters while a video camera simultaneously recorded the visual stimuli. Kinematic data showed 7 distinct relative motion patterns, each invariant despite scaling up of pattern across speeds. Observers in Experiment 1 identified activities on the basis of invariant topological properties of displays. Category judgments were not significantly affected by actual movement speed or by display conditions. Speed estimations appeared to be linked to scaling properties of absolute motion components. Experiment 2 temporally manipulated point-light video display presentations of the same actions. Observers' category judgments were not significantly affected by either actual movement speed or temporal manipulation. Speed estimations were highly correlated with actual movement velocities rather than absolute durations alone.
Results were interpreted as suggesting that the topological invariant distinguishing throwing and bowling is the perceived amount of change in upper- and lower-arm angular relationships while speed estimations reflect scaling properties of absolute motion components. Results of both experiments suggest that all of the necessary information for activity identification and speed estimation is provided by the transformational invariants with little contribution provided by the perception of structural cues.
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1987.
|Date Available in IDEALS:||2014-12-16|
This item appears in the following Collection(s)
Dissertations and Theses - Kinesiology and Community Health
Graduate Dissertations and Theses at Illinois
Graduate Theses and Dissertations at Illinois