Influence of visual constraints in the trajectory formation of grasping movements

Richard Palluel-Germain (1) , Frédéric Boy (1) , Jean-Pierre Orliaguet (1) , Yann Coello

1 LPNC - Laboratoire de Psychologie et NeuroCognition

The main objective of the present study is to show that the visual context can influence the trajectory formation of grasping movements. We asked participants to reach and grasp a cylinder disposed at three different positions: −20°, 0° and 20° of eccentricity with respect to the midsagittal axis. Grasping movements were performed in a direct and in an indirect visual feedback condition (i.e., controlled through a vertical video display). Results revealed that for grasping movements directed toward objects located at −20° and 0°, path curvatures of the wrist, the thumb and the index finger were significantly straighter in the indirect visual feedback condition. However, no significant difference concerning hand path curvature was observed when the movement was directed toward the object located at 20°. This suggests that grasping movements controlled through a remote visual feedback tend to be planned in extrinsic space and that the effect of the visual context on movement planning appears to be not isotropic over the workspace

Mots clés: Natural grasp; Motor planning; Visual feedback; Video-controlled movements; Context effect

Domaines: Psychologie

Richard Palluel-Germain, Frédéric Boy, Jean-Pierre Orliaguet, Yann Coello. Influence of visual constraints in the trajectory formation of grasping movements. Neuroscience Letters, 2006, 401 (1-2), pp.Pages 97-102. ⟨10.1016/j.neulet.2006.02.072⟩. ⟨hal-00175902⟩