Contributed Talks I: Recruiting native visual representations in visual cortex for electrode array based vision...

The possibility to recruit native functional representations, such as orientation preference, by external stimulation in the visual cortex could greatly advance the field of visual prosthetics. However, in blind humans functional properties of neurons cannot be tested directly by measuring neural responses to visual input. A possible solution is based on the idea that functionally similar neurons tend to be more correlated also in the resting condition. Here we present a method to infer the orientation preference map from spontaneous activity recorded with a Utah array from the primary visual cortex of non-human primates. We validated this methods first in a detailed model of primary visual cortex, and subsequently on Utah array recordings from macaque V1. Finally, we applied this method to recordings from blind human volunteers implanted with a cortical visual prosthesis and found that both spatial and functional properties of the set of stimulated electrodes affect perception. Particularly, discrimination between two stimuli becomes easier the more spatially and functionally separated the two sets of stimulated sites are, demonstrating the functional relevance of the decoded visual representations on electrically evoked human perception.