Egocentric and allocentric cues affect visual-auditory fusion in space
Single Paper Presentation

David Hartnagel
IMASSA - Université Paris 8

Alain Bichot
IMASSA

Corinne Roumes
IMASSA

     Abstract ID Number: 132
     Full text: Not available
     Last modified: March 18, 2006
     Presentation date: 06/18/2006 5:30 PM in Hamilton Building, McNeil Theatre
     (View Schedule)

Abstract
Space perception implies egocentric and allocentric cues from multiple sensory modalities. In a luminous environment, the position of the eyes in head affects visual-auditory (VA) fusion in space, the reference frame of VA fusion space is neither head-centered nor eye-centered but is instead the result of an integration phenomenon (Hartnagel et al. 2004). This gaze shift effect appears in total darkness where no allocentric visual cues are available (Hartnagel et al. 2005). Experiments on Induced Roelofs Effect (Bridgeman et al. 1997) showed that visual localization depends on the surrounding visual frame. The present experiment investigates effects of visual allocentric cues on VA fusion space when the reference frames are aligned or dissociated. To ensure that reference frames are aligned or dissociated, the subject’s head was maintained by a bite-board and eye position was checked by an eye-tracker. Two types of allocentric visual cues were tested, the edges of the visual display and 2 broken lines (vertical/ horizontal). A broadband noise burst and a 1° spot of light, 500ms duration, were simultaneously presented with a random spatial disparity. Participants had to judge about their unity. Results showed that AV fusion is dependant of egocentric as allocentric sensory cues.