Chichilnisky Lab

Systems Neurobiology and Sloan-Swartz Center, The Salk Institute

The goal of our research is to understand how neural processing in the retina contributes to visual perception. We exploit unique 512-electrode recordings from the primate retina to examine how the visual scene is encoded by the electrical activity in hundreds of retinal ganglion cells (RGCs) of several distinct types. Some questions under active investigation include:

• How do spatio-temporal patterns of activity in many RGCs signal visual motion to the brain?
• Does synchronized firing in RGCs influence the encoding of visual information?
• How is color information processed and represented in RGCs?
• How reliably can visual stimuli be inferred from RGC activity?
• How do the receptive fields of different RGC types sample the visual scene?
• Can the population activity of many RGCs be understood with simple models?
• Can visual responses of RGCs be reproduced by electrical stimulation?

With these studies we aim to elucidate the nature of population encoding at the first major stage of visual processing. We also hope that our investigation of electrical stimulation will contribute to the development of prosthetic devices for the visually impaired.

We are fortunate to have several active collaborations that greatly enhance our work:

• Alan Litke, University of California, Santa Cruz - technology development and identification of new cell types
• Fred Rieke, University of Washington - fidelity of encoding of photoreceptor activity in the RGC population
• Eero Simoncelli, New York University - models of RGC responses and encoding of natural scene statistics
• Marla Feller, University of California, San Diego - development of retinal circuits
• Tom Albright, Salk Institute - neural processing of color information in visual cortex
• Second Sight, LLC - electrical stimulation for development of visual prostheses

View PBS TV Segment -- January, 2008