TY - JOUR
T1 - Grasping visual illusions
T2 - No evidence for a dissociation between perception and action
AU - Franz, Volker H.
AU - Gegenfurtner, K. R.
AU - Bülthoff, H. H.
AU - Fahle, M.
N1 - 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.
PY - 2000/1
Y1 - 2000/1
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=0033760864&partnerID=8YFLogxK
U2 - 10.1111/1467-9280.00209
DO - 10.1111/1467-9280.00209
M3 - Article
C2 - 11228838
AN - SCOPUS:0033760864
VL - 11
SP - 20
EP - 25
JO - Psychological Science
JF - Psychological Science
SN - 0956-7976
IS - 1
ER -