CMU Neural Engineering Virtual Seminars
Abstract: Blindness affects 40 million people worldwide, and a neuroprosthesis may restore functional vision in the future. We developed a 1024-channel, chronically implantable prosthesis for the monkey visual cortex, using electrical stimulation to elicit percepts of dots of light (‘phosphenes’) across hundreds of electrodes. Phosphene locations matched the receptive fields of stimulated neurons, and V4 activity predicted phosphene detection during stimulation in V1. Next, we stimulated multiple electrodes simultaneously to generate percepts composed of multiple phosphenes. The monkeys could immediately recognize simple phosphene shapes, directions of motion, and letters. We developed techniques such as semi-automatic phosphene mapping and current thresholding, to expedite calibration of a prosthesis. Finally, we tested and validated several of our stimulation and calibration methods in blind human volunteers, demonstrating the potential of electrical stimulation to restore life-enhancing vision in the blind.
About the Speaker: Xing Chen is an Assistant Professor at the University of Pittsburgh Medical Center, specializing in brain-computer interfaces, visual neuroscience, blindness, and chronic recording from and microstimulation of the brain in non-human primates. She obtained her Bachelors in Neuroscience at the University of Southern California on a Trustee Scholarship in 2008, before obtaining her PhD in Neuroscience at Newcastle University in 2014 in the lab of Alexander Thiele. She carried out her postdoctoral work in the lab of Pieter Roelfsema at the Netherlands Institute for Neuroscience, becoming Senior Researcher in 2020. There, she developed 3D modeling and printing techniques to create customized cranial implants to improve implant stability and animal welfare. She co-developed a 1024-channel prosthesis for recording and electrical stimulation of the cortex, establishing proof-of-concept for the feasibility of artificial vision in the blind, winning a Best Poster Award in 2018 at the Amsterdam Neuroscience Meeting and the NIN Brain Award for Scientific Excellence in 2021. In 2019, she co-founded Phosphoenix, a neurotech startup which aims to develop clinical devices that allow profoundly blind people to regain functional vision. Her work has been featured in international and national newspapers, radio and television, including CNN, Science Magazine, Science Podcasts, Scientific American, Het Parool, De Volkskrant, Het Financieele Dagblad, El PaÃs, NOS, NPO Radio, and RTL News.