Krystel Huxlin, Ph.D.
James V. Aquavella Professor of Ophthalmology
University of Rochester

Vision Restoration after Occipital Stroke: Challenging the Limits of Adult Plasticity

In humans, occipital strokes invariably damage the primary visual cortex (V1), causing a loss of conscious vision over large regions of the visual field, referred to as cortically induced blindness (CB). This unfortunate “experiment of nature” afflicts between ¼ to ½ of stroke victims, with rates rising worldwide. Yet, unlike early-onset physical therapies prescribed to rehabilitate motor cortex strokes, there are no accepted vision restoration therapies for CB. Only over the last 2 decades has the assumption that damaged, adult visual systems cannot recover begun to be challenged by accumulating evidence from research in both humans and animal models. This body of work points to one method consistently able to restore a range of visual perceptual abilities after V1 damage: visual training to detect or discriminate stimuli in the blind field. Our group was responsible for key developments in this approach, leading to mechanistic insights, including finding potential redundancies as well as plasticity in the processing of basic visual attributes by residual visual circuits. However, we also uncovered important challenges. Among them, recovery typically requires tens of thousands of trials, and the vision restored is not completely normal; specifically, it appears to be low-contrast, coarse and restricted to the blind field perimeter, limiting its usefulness in everyday life. In this talk, I will summarize evidence for these limitations and explore our initial inroads into overcoming them.

Faculty Host: Kristina Nielsen