Back to publications

Wraga, M., Creem, S. H., & Proffitt, D. R. (2000). Perception-action dissociations of a walkable Muller-Lyer configuration. Psychological Science, 11, 239-243.

These studies examined the role of spatial encoding in inducing perception-action dissociations in visual illusions. Participants were shown a large-scale Muller-Lyer configuration with hoops as its tails. In Experiment 1, participants either made verbal estimates of the extent of the Muller-Lyer shaft (verbal task) or walked the extent without vision in an offset path (blind-walking task). For both tasks, participants stood a small distance away from the configuration, to elicit object-relative encoding of the shaft with respect to its hoops. A similar illusion bias was found in the verbal and motoric tasks. In Experiment 2, participants stood at one endpoint of the shaft in order to elicit egocentric encoding of extent. Verbal judgments continued to exhibit the illusion bias, whereas blind-walking judgments did not. These findings underscore the importance of egocentric encoding in motor tasks for producing perception-action dissociations.

Back to Top


For more information on the Proffitt Perception Lab, please email the webmaster.
102 Gilmer Hall  Box 400400  Charlottesville, VA 22904
(434) 982-4744
Driving Directions