Auditory-somatosensory multisensory interactions: Effects of space and posture
Poster Presentation

Massimiliano Zampini
Department of Cognitive Sciences and Education, University of Trento, Italy

Diego Torresan
Department of Cognitive Sciences and Education, University of Trento, Italy

Charles Spence
Department of Experimental Psychology, University of Oxford, UK

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

     Abstract ID Number: 173
     Full text: Not available
     Last modified: March 19, 2006
     Presentation date: 06/19/2006 4:00 PM in Hamilton Building, Foyer
     (View Schedule)

Abstract
Combined sensory information facilitates perception and behaviour. In terms of auditory-somatosensory interactions, facilitative effects on simple reaction times and brain responses have thus far been demonstrated both when stimuli are presented to the same spatial location and also when stimuli are separated by ~100°. One implication is that brain regions mediating auditory-somatosensory interactions contain large spatial receptive fields. To further investigate this possibility as well as the question of whether auditory-somatosensory interactions are restricted to frontal spatial locations, 12 subjects performed a simple reaction time task to auditory, somatosensory, or simultaneous auditory-somatosensory pairs. Their posture was such that one arm was in front of them and the other behind them. Similarly, one loudspeaker was situated frontally and the other behind. Thus, there were a total of 8 stimulus conditions – 4 unisensory and 4 multisensory – to include all of the combinations of posture and loudspeaker location. Arms positions were counterbalanced across blocks of trials. Responses were made via a foot pedal. Our results indicate a significant facilitation of reaction times following multisensory stimulation, irrespective of the location of either the auditory or somatosensory stimuli. We interpret these results in terms of the likely receptive field properties of auditory-somatosensory brain regions.