Current Research and Scholarly Interests
The goal of our research is to develop an artificial retina -- an electronic implant that will restore vision to people blinded by retinal degeneration. We focus on a combination of basic and applied research to develop an implant that can reproduce the electrical signals that the retina normally transmits to the brain. To accomplish this goal, we work closely with collaborators in fields spanning neurophysiology, electrical engineering, materials science, retinal surgery, visual behavior, and computational neuroscience. This collaboration constitutes the Stanford Artificial Retina Project, funded in part by the Stanford Neurotechnology Initiative.
The design of the implant is based on knowledge acquired in our unique laboratory setting. We use large-scale multi-electrode recording from the retina to study normal light-evoked activity in hundreds of retinal ganglion cells of multiple types simultaneously, and then evoke similar patterns of activity by electrical stimulation. This approach provides a laboratory prototype for the artificial retina. We focus on several questions:
• what visual signals are transmitted by the diverse ganglion cell types to the brain?
• what computational models can accurately reproduce these diverse retinal signals?
• how can we precisely electrically stimulate retinal ganglion cells using an implant?
• how can retinal cell types be recognized and separately targeted by the implant?
• what are the constraints and algorithms for the electronic circuitry in the implant?
• how faithfully can the implant reproduce normal visual sensations in blind patients?
We anticipate that in addition to restoring vision, the artificial retina will allow us to transmit visual information to the brain in ways that are not possible with light stimulation, opening the door to visual augmentation -- creating visual sensations that were never before possible. It will also provide a unique and powerful research instrument for studying the diverse retinal pathways and how they contribute to vision. In the long run, our understanding of the retinal circuitry and how to interface to it effectively will be relevant for developing other interfaces to the brain – for treating disease, and for augmenting human capabilities.
