Audio-visual recalibration is spatially specific, in external coordinates.
David Burr, Roberto Arrighi, Marco Cicchini, David Aagten-Murphy

Date: 2012-06-20 04:00 PM – 05:30 PM
Last modified: 2012-04-24

Abstract


When visual and auditory stimuli are displayed with a spatial offset, the sound is heard at or near the visual stimulus (ventriloquist effect). After an adaptation period of repeated exposure to spatially offset audio-visual stimuli, sounds presented alone are perceived spatially displaced, in the direction of the adapting offset (ventriloquist aftereffect: Recanzione, 1998), pointing to recalibration of audio-visual alignment. Here we show that the recalibration is spatially selective. Adapting, one visual hemifield to (say) a leftward offset, and the other to a rightward (or zero) offset produces two separate spatially localized aftereffects, in opposite directions. If a large (30 deg) eye-movement is interposed between adaptation and test, the spatial specificity remains in head-centered coordinates. [We are currently repeating the experiment with head-movements, to test whether the specificity is head-centered or truly spatiotopic (and will have the answer within a week to modify the abstract)]. The results provide further evidence for the existence of spatiotopic (or at least craniotopic) spatial maps, which are subject to continual recalibration.

References


Recanzione, GH (1998) Rapidly induced auditory plasticity: The ventriloquism aftereffect. Proc. Natl. Acad. Sci., 95, 869-875

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