Recalibration of vision-haptics temporal simultaneity
Poster Presentation

Kohske Takahashi
Shimojo Implicit Brain Function Project, ERATO, Japan Science and Technology

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

Katsumi Watanabe
Research Center for Advanced Science and Technology, the University of Tokyo

     Abstract ID Number: 22
     Full text: Not available
     Last modified: March 4, 2007
     Presentation date: 07/05/2007 10:00 AM in Quad Maclauren Hall
     (View Schedule)

Abstract
Judgments of simultaneity are known to be a flexible process. Adaptation to a pair of stimulus with a fixed temporal lag can alter the point of subjective simultaneity (PSS). The effects of adaptation depend on the combination of sensory modalities used for the simultaneity judgments: lag adaptation in vision-audition, Bayesian adaptation in haptics-haptics, and no shift of PSS in haptics-audition. Here, we investigated the recalibration of vision-haptics temporal simultaneity. In the adaptation phase, subjects experienced visually and haptically deforming virtual objects with a fixed visual-haptic temporal lag (+/- 250 or 0 ms). In the following test phase, the same stimulus was presented with variable lag and subjects judged whether visual and haptic deformations occurred simultaneously. The results showed that the PSS (i.e., the mean of psychometric function) was shifted toward the adapted lag by 10-20 ms. In addition, the temporal window for simultaneity (i.e., the width of psychometric function) was larger when visual deformation preceded haptic deformation. These results suggest that the fashion of vision-haptics temporal recalibration is similar to the vision-audition lag adaptation, and there may be a temporal asymmetry in adaptation process with regard to which modality is preceding.


Acknowledgements
This research was supported by Shimojo Implicit Brain Function Project, ERATO, JST, Japan, PRESTO from JST, Japan, a Grant-in-Aid for Scientific Research, Ministry of Education, Science, and Culture of Japan, no. 16200020, and the 21st Century COE Program from MEXT (D-2 to Kyoto University), Japan.