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Topic: collective dynamics

Seminar
5 seminars

In Dynamical Systems and Computational Neuroscience

Seminar · Computational Neuroscience

The role of sub-population structure in computations through neural dynamics

Srdjan Ostojic · École normale supérieure

Fri, May 19, 2023 · 06:30 UTC

Neural computations are currently conceptualised using two separate approaches: sorting neurons into functional sub-populations or examining distributed collective dynamics. Whether and how these two aspects interact to shape computations is currently unclear. Using a novel approach to extract computational mechanisms from recurrent networks trained on neuroscience tasks, we show that the collective dynamics and sub-population structure play fundamentally complementary roles. Although various tasks can be implemented in networks with fully random population structure, we found that flexible i

Seminar · Computational Neuroscience

The role of population structure in computations through neural dynamics

Alexis Dubreuil · French National Centre for Scientific Research (CNRS), Bordeaux

Wed, Nov 2, 2022 · 06:00 UTC

Neural computations are currently investigated using two separate approaches: sorting neurons into functional subpopulations or examining the low-dimensional dynamics of collective activity. Whether and how these two aspects interact to shape computations is currently unclear. Using a novel approach to extract computational mechanisms from networks trained on neuroscience tasks, here we show that the dimensionality of the dynamics and subpopulation structure play fundamentally com- plementary roles. Although various tasks can be implemented by increasing the dimensionality in networks with ful

Seminar · Computational Neuroscience

When and (maybe) why do high-dimensional neural networks produce low-dimensional dynamics?

Eric Shea-Brown · Department of Applied Mathematics, University of Washington

Thu, Nov 18, 2021 · 16:00 UTC

There is an avalanche of new data on activity in neural networks and the biological brain, revealing the collective dynamics of vast numbers of neurons. In principle, these collective dynamics can be of almost arbitrarily high dimension, with many independent degrees of freedom — and this may reflect powerful capacities for general computing or information. In practice, neural datasets reveal a range of outcomes, including collective dynamics of much lower dimension — and this may reflect other desiderata for neural codes. For what networks does each case occur? We begin by exploring bottom-up

Seminar · Computational Neuroscience

Tuning dumb neurons to task processing - via homeostasis

Viola Priesemann · Max Planck Institute for Dynamics and Self-organization

Fri, Oct 8, 2021 · 12:30 UTC

Homeostatic plasticity plays a key role in stabilizing neural network activity. But what is its role in neural information processing? We showed analytically how homeostasis changes collective dynamics and consequently information flow - depending on the input to the network. We then studied how input and homeostasis on a recurrent network of LIF neurons impacts information flow and task performance. We showed how we can tune the working point of the network, and found that, contrary to previous assumptions, there is not one optimal working point for a family of tasks, but each task may requir

Seminar · Biophysics

Neural network-like collective dynamics in molecules

Arvind Murugan · University of Chicago

Fri, Nov 27, 2020 · 14:00 UTC

Neural networks can learn and recognize subtle correlations in high dimensional inputs. However, neural networks are simply many-body systems with strong non-linearities and disordered interactions. Hence, many-body physical systems with similar interactions should be able to show neural network-like behavior. Here we show neural network-like behavior in the nucleation dynamics of promiscuously interacting molecules with multiple stable crystalline phases. Using a combination of theory and experiments, we show how the physics of the system dictates relationships between the difficulty of the