Abstract
A primary organizing principle of visual cortical organization is the visual field map: neurons with visual receptive fields next to one another in visual space are located next to one another in cortex, forming one complete representation of visual space. Similarly, we have shown that auditory cortex is organized into auditory field maps: neurons with auditory receptive fields that prefer a unique combination of spectral and temporal acoustic dimensions lie next to similarly specialized neurons. Here we investigate the cross-sensory activation of visual field mapping stimuli within auditory field maps and vice versa. We first defined visual field maps V1-hV4 using fMRI and population receptive field (pRF) modeling (Dumoulin & Wandell, 2008). Eleven auditory field maps were defined independently in these same subjects, using tonotopic and periodotopic stimuli with the fMRI travelling wave method modified into a sparse-sampling paradigm (Barton et al, 2012). We then measured activation of visual field maps V1-hV4 by the auditory stimuli and activation of the 11 auditory field maps by the visual stimuli. We find significant activation by auditory stimuli in visual field maps V1-hV4 and significant visual activation of the 11 core and belt auditory field maps. Such similar, efficient organization may be ideal for combining visual and auditory information into a single percept.