Abstract
Neuropsychological studies prompted the theory that the primate visual system might be organized into two parallel pathways, one for conscious perception and one for guiding action. Supporting evidence in healthy subjects seemed to come from a dissociation in visual illusions: In previous studies, the Ebbinghaus (or Titchener) illusion deceived perceptual judgments of size, but only marginally influenced the size estimates used in grasping. Contrary to those results, the findings from the present study show that there is no difference in the sizes of the perceptual and grasp illusions if the perceptual and grasping tasks are appropriately matched. We show that the differences found previously can be accounted for by a hitherto unknown, nonadditive effect in the illusion. We conclude that the illusion does not provide evidence for the existence of two distinct pathways for perception and action in the visual system.
| Original language | English |
|---|---|
| Pages (from-to) | 20-25 |
| Number of pages | 6 |
| Journal | Psychological Science |
| Volume | 11 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 2000 Jan |
Bibliographical note
Funding Information:We wish to thank M.S. Banks and M. Jeannerod for helpful comments on earlier versions of the manuscript. Also, we wish to thank M.A. Goodale and A.M. Haffenden for long and fruitful discussions about our opposite views. This work was supported by a grant from the Deutsche Forschungsgemeinschaft and by the Max-Planck Society.
ASJC Scopus subject areas
- General Psychology