Spatial-contingency effect on illusory flash perception induced by sound and touch
Single Paper Presentation

Michiteru Kitazaki
Research Center for Future Vehicle, Toyohashi University of Technology

Ai Hirata
Department of Knowledge-based Information Engineering, Toyohashi University of Technology

Naoyuki Matsuzaki
Research Center for Future Vehicle, Toyohashi University of Technology

     Abstract ID Number: 20
     Full text: Not available
     Last modified: March 3, 2007
     Presentation date: 07/07/2007 8:40 AM in Quad General Lecture Theatre
     (View Schedule)

Abstract
A single flash is perceived as double with simultaneous presentation of two sounds or two touches (Shams, Kamitani and Shimojo, 2000; Violentyev, Shimojo and Shams, 2005). We investigated the effect of spatial contingency of flash and sound, and that of flash and touch on this phenomenon. Two visual stimuli were presented left and right of the fixation point. One of them was actual double flash (two successive brief flashes), and the other was a single flash. Subjects were asked to judge whether the double flash was right or left. In addition to visual stimuli, a single or double sound was presented at various positions with manipulating sound pressures of two loudspeakers in Experiment 1. In Experiment 2, a double touch was presented on either the left or right index finger, which was behind of the visual stimuli. In results, the flash at the same orientation of the double sounds (Experiment 1) or of the double touch (Experiment 2) was more likely perceived as double flashes. These results suggest that the cross-modal flash illusion was not limited to the temporal dimension, but can be modulated with the spatial contingency.