Motion afereffect in a multimodal sensory system
Single Paper Presentation

Tatjana Seizova-Cajic
School of Psychology, University of Sydney

W L Ben Sachtler
University of New South Wales

     Abstract ID Number: 37
     Full text: Not available
     Last modified: March 5, 2007
     Presentation date: 07/07/2007 11:30 AM in Quad General Lecture Theatre
     (View Schedule)

Abstract
Motion perception in vision is influenced by other senses that inform about head and eye movements. Indeed, illusory motion of a visual target can be induced by propriceptive stimulation (neck vibration) that provides a false signal about head movement. When vibration stops, a motion aftereffect is perceived. We asked whether the site responsible for the aftereffect is purely proprioceptive or is instead bimodal (an area where retinal input is combined with the input from proprioceptors to give egocentric target position). In the critical condition, the neck was vibrated in total darkness for variable periods of time. Bimodal structures should be silent during vibration in darkness; nevertheless, the visual motion aftereffect occurred, showing that a solely proprioceptive adaptation site was responsible. However, the motion aftereffect was stronger in the condition in which the target was visible during vibration, revealing that bimodal structures also adapt. We conclude that adaptation to visual motion occurs at different levels of a multimodal sensory system, and that it is greatest at the level where multimodal inputs combine.