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Image: Dystrophic Corticospinal Rat Neurons Following Spinal Cord Injury – Blue- Nathaniel Peters

Greg Horwitz, PhD

Professor
HSB I714, I728, G230

Neural Basis of Visual Perception

Vision is the result of computations occurring in the eye and brain. We want to understand what these computations are and how they are implemented by neurons.

Our current research focuses on color vision. Thanks to decades of physiological and psychophysical studies, we know a great deal about how color is processed in the eye and about human color perception. We know relatively little, however, about the links between the two, that is, how color is processed in the cerebral cortex. Our primary experimental techniques are electrophysiological (single neuron recording and electrical microstimulation), psychophysical (measurement of detection thresholds), and computational (analysis of spike-triggered stimulus distributions). We are particularly interested in interactions between visual pathways that may serve to enhance color perception at luminance edges.

We are also exploring gene delivery techniques to manipulate components of the visual system and thereby tease apart their contributions to perception. We are developing in vivo assays of gene products that enhance or suppress neuronal signaling, and we are investigating methods for targeting virally mediated gene expression to specific subclasses of neurons.