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Louis Pezon

@lpezon.bsky.social
85 followers 21 following 11 posts

PhD student in computational & theoretical neuroscience, with Wulfram Gerstner @ EPFL. Theories of computation via low-dimensional dynamics in recurrent neural networks.

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Louis Pezon @lpezon.bsky.social · 28/09/2026
How can RNNs re-use the same dynamics across different tasks to implement compositional computation? What are the consequences for network connectivity & activity? If you're interested, come and find out at the Bernstein Conference, poster session III-#48!
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Reposted by Louis Pezon
GerstnerLab @gerstnerlab.bsky.social · 29/06/2026
How can the brain learn the hidden hierarchical structure from high dimensional data? In our latest work, we use synthetic datasets to analyze two classes of bio-plausible learning rules: variants of Direct Feedback Alignment, and local self-supervised learning. We find only the latter succeeds.
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Louis Pezon @lpezon.bsky.social · 30/06/2026
Finally, how do 𝑠ℎ𝑎𝑟𝑒𝑑 latent components enable 𝑡𝑎𝑠𝑘-𝑑𝑒𝑝𝑒𝑛𝑑𝑒𝑛𝑡 computation? Our framework explicitly identifies several potential loci at which task-dependence can be resolved. This yields a qualitative, interpretable description of compositional computation in RNNs.
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Louis Pezon @lpezon.bsky.social · 30/06/2026
We derive consequences of such shared 𝑙𝑎𝑡𝑒𝑛𝑡 components: (i) They are compatible with task-dependent activity, observed consistently in brains and RNNs. (ii) They constrain connectivity statistics and neural representations, and are detectable via specific experiments.
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Louis Pezon @lpezon.bsky.social · 30/06/2026
We develop a theory of compositional computation in low-rank RNNs. Low-rank nets perform computation via low-dimensional latent dynamics. We propose that “shared components” exist at this level — more precisely, that networks re-use 𝑎𝑢𝑡𝑜𝑛𝑜𝑚𝑜𝑢𝑠 𝑙𝑎𝑡𝑒𝑛𝑡 𝑑𝑦𝑛𝑎𝑚𝑖𝑐𝑠 across tasks.
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Louis Pezon @lpezon.bsky.social · 30/06/2026
Both brains and RNNs can re-use components of computation across similar tasks or contexts. But what exactly are those “shared components”? How can they be used to solve several tasks? We address these questions in a new preprint with @avm.bsky.social! Link: www.biorxiv.org/content/10.6...
biorxiv.org
Interpretable compositional computation with recurrent neural networks
Flexible cognition utilizes reusable components to enable rapid adaptation of behavior to different contexts or tasks. Analysis of artificial neural networks trained on multiple tasks suggested that t...
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Reposted by Louis Pezon
Flavio Martinelli @flavioh.bsky.social · 10/06/2026
NEW PAPER. Why do larger networks train better? "Because they contain more candidate *sub*networks that can learn the task" → lottery tickets This popular explanation uses an appealing but misleading metaphor🧵 We propose an intuitive alternative grounded in theory: escape dimensions
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Reposted by Louis Pezon
Valentin Schmutz @bio-emergent.bsky.social · 08/05/2026
Unbelievably honoured to read Tatiana Engel's (@engeltatiana.bsky.social) wonderfully written Preview on our work "Linking neural manifolds to circtuit structure in recurrent networks" (with @lpezon.bsky.social & @gerstnerlab.bsky.social) in this issue of Neuron www.cell.com/neuron/fullt... 🙏
cell.com
Finding clues to circuit structure in population dynamics and single-neuron selectivity
In this issue of Neuron, Pezon et al. introduce neural circuit models with flexible connectivity structure that can generate low-dimensional population dynamics with different distributions of single-...
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Louis Pezon @lpezon.bsky.social · 13/03/2026
Presenting a poster tomorrow at Cosyne 26: [3-033] Compositional computation via shared latent dynamics in low-rank RNNs. With @avm.bsky.social, we explore how RNNs can re-use the same dynamics across different tasks, and what it implies for their connectivity and neural activity.
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Alexander van Meegen @avm.bsky.social · 12/03/2026
Travelling to COSYNE seems to be the perfect opportunity to announce that I started my own lab at RWTH Aachen University earlier this year, funded by NRW's Ministry of Culture and Science through its Return Program. If you are at COSYNE and want to chat please reach out!
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Louis Pezon @lpezon.bsky.social · 06/03/2026
[About the theory] To tackle this problem, we developed a unifying framework for the theory of neural fields and low-rank RNNs. We show that low-rank nets rely on an implicit spatial structure, and conversely, that neural fields obey latent dynamics akin to low-rank nets.
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Louis Pezon @lpezon.bsky.social · 06/03/2026
3. We find that the circuit structure – can impose symmetries on the network's low-dim. dynamics – constrains the topology of the set of all single-neuron responses. From the second point, we pinpoint topological features of neural activity relevant for comparing it with models.
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Louis Pezon @lpezon.bsky.social · 06/03/2026
2. We find that “function does not determine form”: the same computation (i.e., the same low-dim. dynamics) can be implemented by networks with different circuit structures. Yet, circuit structure imposes subtle constraints on neural activity (see next).
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Louis Pezon @lpezon.bsky.social · 06/03/2026
1. Neural activity is often analyzed in two ways: – low-dimensional dynamics in neural manifolds reflect computations – single-neuron response properties (e.g., tuning, selectivity) can describe how the neural population is organized. But it's not clear how this relates to network connectivity.
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Louis Pezon @lpezon.bsky.social · 06/03/2026
Excited to share our new paper to be published in Neuron! With Valentin Schmutz @bio-emergent.bsky.social and Wulfram Gerstner @gerstnerlab.bsky.social, we explore how circuit structure in RNNs shapes network computation and single-neuron responses. www.sciencedirect.com/science/arti...
sciencedirect.com
Linking neural manifolds to circuit structure in recurrent networks
Dimensionality reduction methods are widely used in neuroscience to investigate two complementary aspects of neural activity: the distribution of sing…
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