Help Privacy Policy Disclaimer
  Advanced SearchBrowse


  Looking During Grasping

Brouwer, A.-M., Franz, V., Kerzel, D., & Gegenfurtner, K. (2005). Looking During Grasping. Poster presented at 8th Tübinger Wahrnehmungskonferenz (TWK 2005), Tübingen, Germany.

Item is


show Files




Brouwer, A-M1, 2, Author           
Franz, V, Author           
Kerzel, D, Author
Gegenfurtner, KR, Author           
1Department Human Perception, Cognition and Action, Max Planck Institute for Biological Cybernetics, Max Planck Society, ou_1497797              
2Max Planck Institute for Biological Cybernetics, Max Planck Society, ou_1497794              


Free keywords: -
 Abstract: In a grasping task, Johansson et al. [1] found that subjects look at the position to which the finger tips are guided. However, in their experiment, only the contact position of the thumb
was visible. We investigated what happens if the contact positions of both finger and thumb are
visible. We recorded eye and finger movements. In a first experiment, subjects always grasped
with the index finger at the top and the thumb at the bottom of a flat shape that was mounted on
a horizontal bar. In order to see whether a salient feature of a shape would affect the fixation
positions, we presented an (asymmetric) cross in 4 orientations (with the crossing of the bars
representing the salient feature). In order to see whether gaze is attracted to the position where
the finger has to be guided relatively precisely, we presented a triangle in two orientations that
subjects had to contact at the base and at the pointed top (i.e., a higher required precision to
contact the top than the base). We found that the crossing of the bars attracted the gaze whereas
the top of a triangle did not. A prominent result was that subjects fixated above the center of
the shape. In order to distinguish between subjects fixating the upper part of the shape versus
being attracted by the index finger, we mounted a square and a triangle in two orientations on a
vertical bar. We asked subjects to grasp first with one hand and then with the other so that the
shape remained constant but the contact positions of the index finger and thumb were reversed.
Subjects still looked above the center. In addition, for the square the gaze was now attracted to
the thumb so that the average fixation location was to the left or to the right half of the square,
depending on the used hand. The latter result indicates that gaze not only depends on the shape
but also on features of the grasp. This is also supported by the finding that the variability in
fixation locations was more in the horizontal direction for the second experiment than for the
first, i.e. the variability tends to be along the grasping axis. We conclude that both features of
the shape and the grasp affect gaze location.


 Dates: 2005-02
 Publication Status: Published in print
 Pages: -
 Publishing info: -
 Table of Contents: -
 Rev. Type: -
 Identifiers: BibTex Citekey: BrouwerFKG2005
 Degree: -


Title: 8th Tübinger Wahrnehmungskonferenz (TWK 2005)
Place of Event: Tübingen, Germany
Start-/End Date: 2005-02-25 - 2005-02-27

Legal Case


Project information


Source 1

Title: 8th Tübingen Perception Conference: TWK 2005
Source Genre: Proceedings
Bülthoff, HH1, Editor           
Mallot, HA, Editor           
Ulrich, R, Editor
Wichmann, FA1, Editor           
1 Max Planck Institute for Biological Cybernetics, Max Planck Society, ou_1497794            
Publ. Info: Kirchentellinsfurt, Germany : Knirsch
Pages: - Volume / Issue: - Sequence Number: - Start / End Page: 161 Identifier: -