Auditory-visual spatial receptive fields in ferret auditory cortex
Poster Presentation

Jennifer Bizley
Deparment of Physiology, Anatomy and Genetics, University of Oxford

Andrew King
Deparment of Physiology, Anatomy and Genetics, University of Oxford

     Abstract ID Number: 78
     Full text: Not available
     Last modified: May 30, 2007
     Presentation date: 07/06/2007 10:00 AM in Quad Maclauren Hall
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Abstract
We have recently shown that neurons in ferret auditory cortex can be driven, or have their auditory responses modulated, by simultaneously presented visual stimuli (Bizley et al., 2007, Cerebral Cortex). These multisensory responses are widespread in non-primary areas, but also exist in primary fields. Measures of mutual information (MI) revealed that bimodal stimulation increases the stimulus-related information transmitted by the neurons and that this information is present in the timing as well as the number of evoked spikes. We have now characterized the spatial receptive fields of multisensory neurons in all the auditory cortical fields that have been identified by carrying out single- and multi-unit recordings in anaesthetized ferrets. Stimuli comprised 100 ms broadband noise bursts presented in virtual acoustic space and/or 100 ms visual stimuli presented from LEDs that were positioned in front of the animal to match the virtual locations of the auditory stimuli. The extent to which individual neurons were spatially tuned to either stimulus modality was quantified using an MI analysis. Visual receptive fields were broad throughout auditory cortex, but particularly in the primary fields, suggesting that the greater incidence of multisensory convergence in non-primary areas may be related to the processing of spatial information.