Auditory-visual interactions affect subsequent visual responsiveness: An electrical neuroimaging study using rudimentary stimuli
Poster Presentation

Raphaël Meylan
The Functional Electrical Neuroimaging Laboratory, Neuropsychology Division, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland

Micah M. Murray
The Functional Electrical Neuroimaging Laboratory, Neuropsychology Division and Radiology Service, Centre Hospitalier Universitaire Vaudois, Lausanne Switzerland

     Abstract ID Number: 65
     Full text: Not available
     Last modified: March 16, 2006
     Presentation date: 06/19/2006 4:00 PM in Hamilton Building, Foyer
     (View Schedule)

Abstract
The effects of multisensory interactions on the later treatment of other incoming sensory input remain relatively unknown. We investigated whether multisensory interactions between rudimentary auditory and visual stimuli (3.5kHz beeps and circular flashes; 13ms duration) affect subsequent visual processing. A 2x2 design varied the number of beeps (0 or 1) with the number of flashes (1 or 2) presented on each trial, such that ‘1b2f’ refers to the presentation of 1 beep with 2 flashes. Beeps, when present, were synchronous with the first flash, and pairs of flashes were separated by a 52ms ISI. Subjects indicated the number of flashes presented on each trial. Electrical neuroimaging of 128-channel event-related potentials assessed both the electric field strength and topography. Contrasting the difference between the 0b2f and 0b1f conditions with the difference between the 1b2f and 1b1f conditions [(0b2f-0b1f) vs. (1b2f-1b1f)] isolated the response to the second flash and removed responses to the initial flash or multisensory pair. We found significant differences beginning ~170ms after the onset of the second flash. The treatment of subsequent visual information was attenuated when preceded by a multisensory event. Multisensory events thus affect later sensory processing. (Supported by the Swiss National Science Foundation and Leenaards Foundation)