A novel interface for cortical columnar neuromodulation with multi-point infrared neural stimulation

Cutting edge advances in electrical visual cortical prosthetics have evoked perception of shapes, motion, and letters in the blind. Here, we present an alternative optical approach using pulsed infrared neural stimulation. To interface with dense arrays of cortical columns with submillimeter spatial precision, both linear array and 100-fiber bundle array optical fiber interfaces were devised. We delivered infrared stimulation through these arrays in anesthetized cat visual cortex and monitored effects by optical imaging in contralateral visual cortex. INS modulation of response to ongoing visual oriented gratings produced enhanced responses in orientation-matched domains and suppressed responses in non-matched domains, consistent with a known higher order integration mediated by callosal inputs. Controls included dynamically applied speeds, directions and patterns of multipoint stimulation. This provides groundwork for a distinct type of prosthetic targeted to maps of visual cortical columns.