Controlling brain activity and perception in primates

The activity of neurons in the primate brain is directly linked to perception. We propose to investigate whether we can replace elements of visual experience in the form of complex visual percepts. Indeed, this is a pre-requisite for any visual prosthesis. In order to achieve this, we will use a new kind of laminar probe that is able to do multisite recordings or stimulation across all layers of the visual cortex. Probes will be implanted in healthy non-human primates' primary visual cortex (V1) or used acutely in extrastriate area V5/MT. In both areas, we will collect high-resolution electrophysiology recordings. Recordings will be used to design stimulation patterns adapted to each target. In an initial experiment, we will show that our system is able to evoke visual percept, called phosphenes, by electrically stimulating V1 by making the animal perform a detection task. To progress from phosphenes to complex percepts, will also test whether electrical V1 microstimulation can skew the monkey's perception of a more complex visual stimulus. In V5/MT, we will do multisite recordings to understand better how a complex stimulus (eg. combining motion and disparity) is coded and how the stimulation across several sites can alter its perception. Complementarily, we will use fMRI to evaluate how much of the visual system is recruited by each target's stimulation, and the effect of chronic stimulation on the visual cortex's connectivity.

This project fits in the frame of the Bioscience for Health BBSRC priority area. Indeed, this framework sets for aim the discovery of deep, integrated understanding of the 'healthy system' at multiple levels. Nowadays, the UK has to face the challenges linked to an ageing population. Therefore, four key challenges have been defined: Nutrition and Health, One Health, Biotechnology for Health and Lifelong Health which aims to correct the diseases, like vision impairment, linked to ageing by the understanding of the young healthy subject.

BfH, ENWW