Pieter Roelfsema
Netherlands institute for neuroscience, Amsterdam, The Netherlands.
RESEARCH INTEREST:
Pieter studies visual perception, learning and memory in the visual system in humans, laboratory animals and artificial neural networks. He studies how nerve cells in different brain areas cooperate in tasks that require us to think about what we see. He wants to know how cells in brain areas cooperate and how they form during the learning of a new task.
An important goal of his lab is to develop a visual prosthesis that would allow people who have become blind to regain a simple form of sight. Pieter coordinates NeuroTech-NL, and the INTENSE grant from NWO to develop new neurotechnology
Keynote Talk: Creating a visual prosthesis by interfacing with the visual thalamus
A long-standing dream of scientists is to be able to directly project images from the outside world onto the visual brain, bypassing the eyes. This method could provide a solution for blind and visually impaired patients. It is the only possible solution for patients in whom the connection between eye and brain is lost so that a prosthesis in the eye is not an option.
I will first give an overview of the functioning of the LGN and visual cortex, where lower level brain regions analyze simple visual features and higher areas more complex properties such as object category and faces. I will then discuss the mechanisms that determine whether a visual stimulus will reach consciousness or not. It is well established that the electrical stimulation of electrodes in the visual brain leads to artificial percepts called "phosphenes". This method also works in patients who have been blind for decades. The goal of our own research is to bring a prosthesis for the visual brain closer. We implanted 1000 electrodes in the visual cortex to generate complex visual patterns. We demonstrated that this stimulation leads to interpretable images, in the same way that pixels form recognizable patterns on a screen. We are now looking into possibilities to interface with the LGN, which would facilitate clinical translation. These new neurotechnological developments take important steps in the direction of prostheses that can restore a rudimentary form of vision.
