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Updated: Aug 11, 2026
09:49
Methods to Explore the Influence of Top-down Visual Processes on Motor Behavior
Published on: April 16, 2014
Are perception and action affected differently by the Titchener circles illusion?
F Pavani1, I Boscagli, F Benvenuti
1Dipartimento di Psicologia, Università degli Studi di Bologna, Italy. pavanif@psibo.unibo.it
Experimental Brain Research
|July 29, 1999
Summary
The Titchener circles illusion affects both perception and action, contrary to previous beliefs. Grip scaling during grasping is influenced by the illusion, showing interaction between perception and action pathways.
Area of Science:
- Cognitive Psychology
- Neuroscience
- Visual Perception
Background:
- The Titchener circles illusion (Ebbinghaus illusion) demonstrates size contrast, where identical circles appear different due to surrounding context.
- Previous research suggested a dissociation between perception and action, as grip aperture during grasping was not affected by the illusion.
Purpose of the Study:
- To investigate the influence of the Titchener circles illusion on both perception and action.
- To test the hypothesis that previous studies on action dissociation were flawed due to experimental design.
Main Methods:
- 18 subjects perceptually estimated and grasped a central disc.
- The disc was presented within a single annulus of surrounding circles to isolate the illusion's effect.
Main Results:
- Both perceptual estimates and grip aperture during grasping were significantly influenced by the Titchener circles illusion.
- A stronger perceptual illusion led to a greater effect on grip scaling.
Conclusions:
- The findings suggest an interaction between the functional pathways for perception and action, challenging the notion of a clear dissociation.
- The study provides evidence that visuomotor behavior is not independent of perceptual illusions.
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