Illusory spatial perception induced by the temporal discrepancy between modalities in dynamic vision-haptics integration
Single Paper Presentation

Kohske Takahashi
Graduate School of Informatics, Kyoto University

Jun Saiki
Graduate School of Human and Environmental Studies, Kyoto University

     Abstract ID Number: 142
     Full text: Not available
     Last modified: March 19, 2006
     Presentation date: 06/18/2006 4:00 PM in Hamilton Building, Foyer
     (View Schedule)

Abstract
We demonstrated that the illusory spatial perception occurred because of the temporal discrepancy between modalities when the dynamic event was estimated through vision and haptics.
The observers estimated the amount of deformation of an object which was looked at and touched, and the perceived amount of deformation was measured. The stimulus was a rectangular solid object with 40 mm depth that compressively deformed along the depth axis. The observers asked to answer the interval of the larger deformation (2IFC paradigm).
In experiment 1, the duration of deformation was 500 ms and the temporal asynchrony between modalities (+/- 60, 30, 0 ms) was introduced in one interval. The larger asynchrony made the perceived amount of deformation smaller than the physical amount. The illusory perception was quantitatively predicted by the modified weighted linear summation model. In experiment 2, the asynchrony was +/- 60 ms and the duration of deformation was different between modalities (500 ms for haptic and 500, 440, 380 ms for vision). The different duration between modalities induced the different illusory effect, suggesting that the different dynamics between modalities destructed the linear integration. The discrepancy of the dynamics between modalities affects the integration process, resulting in the illusory spatial perception.