Speakers > Yoram Burak
Yoram Burak is an Associate Professor at the Racah Institute of Physics and the Safra Center for Brain Sciences, at the Hebrew University of Jerusalem, where he is the incumbent of the William N. Skirball Chair in Neurophysics. Before joining the Hebrew University in 2012, he was a Swartz postdoctoral fellow in theoretical neuroscience at the Center for Brain Science at Harvard University, and a postdoctoral research associate at the Kavli Institute for Theoretical Physics at UCSB. His research aims to identify how neural circuits in the brain implement computational functions.
Stochastic dynamics of neural representations residing in low dimensional manifolds: from motor control to spatial cognition
One of the most fundamental concepts in theoretical neuroscience is that of an attractor neural network, in which recurrent synaptic connectivity constraints the joint activity of neurons into a highly restricted repertoire of population activity patterns. In continuous attractor networks, these activity patterns span a continuous, low-dimensional manifold. I will survey research from my group which is related to this concept, focusing on two recent works. In one work we examined for the first time the joint dynamics of grid cells in the entorhinal cortex of rats that belong to different modules, using high density silicon probe recordings. We hypothesized that in order for grid cells to implement together an efficient coding scheme for position, network mechanisms must coordinate the activity of different grid cell modules, even when the internal representation of position in the brain deviates from the true position of the animal. To test this hypothesis, we analyzed the activity of hundreds of grid cells that were simultaneously recorded in animals that were foraging in the dark. The second work is concerned with fixational eye drifts, a form of eye motion that occurs between saccades and is characterized by smooth, yet random, diffusive-like motion. Fixational drift has been identified at least as early as the 19th century, and has been extensively studied since then, yet its mechanistic origins remained unknown. I will present experimental and theoretical evidence that the main drive for the motion is in the oculomotor integrator, a continuous attractor network which is responsible for maintaining a fixed activation of the ocular muscles between saccades.
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