The goals of this project are: (1) to determine the spatial and temporal characteristics of auditory-visual integration in individuals with low vision; (2) to explore visual influence over auditory perception through audiovisual integration in late blind and low vision individuals using visual mental imagery; and (3) to directly assess the residual strength of crossmodal connections among the visual, auditory, and multisensory cortices in both low vision and late blind individuals using functional magnetic resonance imaging (fMRI).

For example, in order to determine the spatial and temporal characteristics of auditory-visual integration in individuals with low vision, we employ a number of crossmodal illusions, such as the Double Flash Illusion and the Illusory Audiovisual Rabbit Illusion, to evaluate the strength of crossmodal connections throughout the visual field of patients with low vision deriving from Retinitis Pigmentosa (RP), Age-Related Macular Degeneration (AMD), and Non-Arteritic Anterior Ischemic Optic Neuropathy (NAION), among other low vision conditions. 

In pilot studies, we showed in one patient that the strength of crossmodal interactions throughout the visual field in the impaired eye with a trauma-induced scotoma was significantly enhanced relative to that in the opposite eye with normal visual perception, and also relative to that in sighted controls.

We plan to correlate these intriguing results with a direct assessment of the residual strength of crossmodal connections among the visual, auditory, and multisensory cortices using functional magnetic resonance imaging (fMRI).