Visual Perception of Biological Motion

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.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Kinesiology

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2014

Author dc:creator

• Scully, Deirdre Maire

Contributors dc:contributor

• Newell, Karl M.

• Psychology, Experimental

Identifier

(UMI)AAI8803196

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/71075