Edvard I. Moser, Norwegian University of Science and Technology
In this Staudinger Lecture, Edvard Moser discussed recent advances in our understanding of the brain´s mechanisms for tracking space and time, brain functions that are generated not merely by integration of sensory inputs but rather by internal dynamics of the cortex. In mammals, space is mapped by complex neural networks in the hippocampus and medial entorhinal cortex. These brain areas contain specialized position-coding cell types, including the grid cells of the medial entorhinal cortex – cells that are active when animals are at specific locations that tile environments in a periodic hexagonal pattern. Moser showed how recent technological developments allow the dynamics of thousands of neurons to be monitored during behavior. Based on experiments with these new technologies, he showed how the dynamics of grid cells arises in interactions among large neural populations and how the joint activity of grid cells operates on a low-dimensional manifold with the topology of a torus, in agreement with continuous attractor network models of grid cells. He further showed how time and sequences are encoded across seconds to hours in the population state space of entorhinal neural networks and how specialized dynamics of the lateral part of entorhinal cell populations provides the brain with a neural code that uniquely expresses the passage of cumulative experience correlated with time.