In the present study we attempted to determine the nature of the visual analysis that is performed on an object in order to grasp it. We required eight healthy subjects to reach and grasp a wooden bar which was superimposed over the shaft of the Müller-Lyer illusion. Vision of both the hand and the bar was allowed. Three different bar lengths were used. Two additional control tasks in which the subjects were required to reproduce the length of the shafts were carried out. The results showed that hand shaping while grasping the bar was influenced by the illusion configurations on which it was superimposed. However, this effect was smaller than that observed in the two tasks of length reproduction. These results support the notion that visual analysis performed on the object of a grasp movement is global and takes into account the object itself, as well as its relationships with surrounding cues. We propose, as suggested previously for reaching movements (Gentilucci, M. et al., Neuropsychologia, 1996, 34, 369-376), two partially independent stages during visuo-motor integration for grasping an object. In the first stage, the object is coded inside an object-centred frame of reference. In the second stage it is transposed in an egocentric frame of reference, in which the spatial relations between object and agent are computed. In this second stage the influence of cues surrounding the target is minimized.
Daprati, E., & Gentilucci, M. (1997). Grasping an illusion. NEUROPSYCHOLOGIA, 35(12), 1577-1582 [10.1016/S0028-3932(97)00061-4].
|Tipologia:||Articolo su rivista|
|Citazione:||Daprati, E., & Gentilucci, M. (1997). Grasping an illusion. NEUROPSYCHOLOGIA, 35(12), 1577-1582 [10.1016/S0028-3932(97)00061-4].|
|IF:||Con Impact Factor ISI|
|Settore Scientifico Disciplinare:||Settore BIO/09|
|Revisione (peer review):||Sì, ma tipo non specificato|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1016/S0028-3932(97)00061-4|
|Stato di pubblicazione:||Pubblicato|
|Data di pubblicazione:||dic-1997|
|Titolo:||Grasping an illusion|
|Autori:||Daprati, E; Gentilucci, M|
|Appare nelle tipologie:||01 - Articolo su rivista|