Combining Vision and Touch in Object Length Perception
Poster Presentation

Kazunori Terada
Gifu University

Akinori Kumazaki
Gifu University

Akira Ito
Gifu University

     Abstract ID Number: 88
     Full text: Not available
     Last modified: March 17, 2006
     Presentation date: 06/20/2006 10:00 AM in Hamilton Building, Foyer
     (View Schedule)

Abstract
When a human recognize length of an object while exploring it with their index finger, haptic and visual sensation both provide information for estimating the length of the object. The present study examined the contribution of tactile and visual cues to the subjective estimation of object length. The subject's index finger was passively moved laterally along a straight path by an apparatus driven by a linear actuator with slide guides. The subjects see his/her hand through a LCD which was located at about chest level horizontally. The visual stimulus velocity was controlled by a real time image processing system so that the subject could perceive different visual length from tactile length. The finger pad touched the raised dot surface during each trial and edge of the stimulus object both beginning and completion of stimulus presentation. Then the subject gave a magnitude estimate of the length. The subjects were tested under two experimental conditions: (1) bimodal condition in which visual and tactile length varied from 10 to 15 cm respectively; (2) unimodal condition in which only visual or tactile length was presented (control condition). The results were as follows: (1) mltisensory enhancement was not observed when the visual and tactile presented length was the same; (2) visual cues were weighted 69% and tactile cues 31% in the bimodal judgements.