Alex van Meegen
@avm.bsky.social
260 followers 360 following 5 posts
Theory of Neural Networks (how the heck do they work?) | Postdoc @EPFL, prev. Swartz Fellow @Harvard and PhD @FZJuelich | https://alexvanmeegen.github.io | Background art by https://bettina-hachmann.de
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Reposted by Alex van Meegen
bio-emergent.bsky.social
🎉 "High-dimensional neuronal activity from low-dimensional latent dynamics: a solvable model" will be presented as an oral at #NeurIPS2025 🎉

Feeling very grateful that reviewers and chairs appreciated concise mathematical explanations, in this age of big models.

www.biorxiv.org/content/10.1...
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Reposted by Alex van Meegen
gerstnerlab.bsky.social
Lab members are at the Bernstein conference @bernsteinneuro.bsky.social with 9 posters! Here’s the list:

TUESDAY 16:30 – 18:00

P1 62 “Measuring and controlling solution degeneracy across task-trained recurrent neural networks” by @flavioh.bsky.social
avm.bsky.social
Awesome. Congratulations!!
Reposted by Alex van Meegen
roxana-zeraati.bsky.social
Check out our new preprint where we analyzed the dynamics of over ten thousand neurons across 223 brain areas and found a surprising universal principle that describes the organization of intrinsic timescales across the entire mouse brain, including subcortical structures!
#neuroskyence
shiyanliang.bsky.social
Excited to share our new preprint on the brain-wide organization of intrinsic timescales at single neuron resolution. Work w/ @roxana-zeraati.bsky.social, @intlbrainlab.bsky.social, Anna Levina, @engeltatiana.bsky.social : www.biorxiv.org/content/10.1...
Reposted by Alex van Meegen
neurovenki.bsky.social
Excited to share new computational work, led by @jzv.bsky.social, driven by Juan Carlos Fernandez del Castillo + contribution from Farhad Pashakanloo. We recover 3 core motifs in the olfactory system of evolutionarily distant animals using a biophysically-grounded model + efficient coding ideas!
Convergent motifs of early olfactory processing are recapitulated by layer-wise efficient coding
The architecture of early olfactory processing is a striking example of convergent evolution. Typically, a panel of broadly tuned receptors is selectively expressed in sensory neurons (each neuron exp...
www.biorxiv.org
Reposted by Alex van Meegen
antihebbiann.bsky.social
I wrote a Comment on neurotheory, and now you can read it!

Some thoughts on where neurotheory has and has not taken root within the neuroscience community, how it has shaped those subfields, and where we theorists might look next for fresh adventures.

www.nature.com/articles/s41...
Theoretical neuroscience has room to grow
Nature Reviews Neuroscience - The goal of theoretical neuroscience is to uncover principles of neural computation through careful design and interpretation of mathematical models. Here, I examine...
www.nature.com
Reposted by Alex van Meegen
david-g-clark.bsky.social
Wanted to share a new version (much cleaner!) of a preprint on how connectivity structure shapes collective dynamics in nonlinear RNNs. Neural circuits have highly non-iid connectivity (e.g., rapidly decaying singular values, structured singular-vector overlaps), unlike classical random RNN models.
Connectivity structure and dynamics of nonlinear recurrent neural networks
Studies of the dynamics of nonlinear recurrent neural networks often assume independent and identically distributed couplings, but large-scale connectomics data indicate that biological neural circuit...
arxiv.org
Reposted by Alex van Meegen
sussillodavid.bsky.social
Coming March 17, 2026!
Just got my advance copy of Emergence — a memoir about growing up in group homes and somehow ending up in neuroscience and AI. It’s personal, it’s scientific, and it’s been a wild thing to write. Grateful and excited to share it soon.
Reposted by Alex van Meegen
violapriesemann.bsky.social
Physik studieren? Oder ein anderes Fach?

In Göttingen geht jetzt beides, mit dem "Bachelor Interdisziplinär", der Physik mit spannenden Disziplinen Eurer Wahl, wie z.B. Künstlicher Intelligenz, Philosophie, Neurowissenschaften, ... kombiniert.

www.uni-goettingen.de/de/studium/6...
Studiengang Physik interdisziplinär - Georg-August-Universität Göttingen
Webseiten der Georg-August-Universität Göttingen
www.uni-goettingen.de
Reposted by Alex van Meegen
engeltatiana.bsky.social
Out today in @nature.com: we show that individual neurons have diverse tuning to a decision variable computed by the entire population, revealing a unifying geometric principle for the encoding of sensory and dynamic cognitive variables.
www.nature.com/articles/s41...
Reposted by Alex van Meegen
david-g-clark.bsky.social
(1/23) In addition to the new Lady Gaga album "Mayhem," my paper with Manuel Beiran, "Structure of activity in multiregion recurrent neural networks," has been published today.

PNAS link: www.pnas.org/doi/10.1073/...

(see dclark.io for PDF)

An explainer thread...
Structure of activity in multiregion recurrent neural networks | PNAS
Neural circuits comprise multiple interconnected regions, each with complex dynamics. The interplay between local and global activity is thought to...
www.pnas.org
avm.bsky.social
Interested in high-dim chaotic networks? Ever wondered about the structure of their state space? @jakobstubenrauch.bsky.social has answers - from a separation of fixed points and dynamics onto distinct shells to a shared lower-dim manifold and linear prediction of dynamics.
jakobstubenrauch.bsky.social
(1/3) How to analyse a dynamical system? Find its fixed points, study their properties!

How to analyse a *high-dimensional* dynamical system? Find its fixed points, study their properties!

We do that for a chaotic neural network! finally published: doi.org/10.1103/Phys...
Fixed point geometry in chaotic neural networks
Understanding the high-dimensional chaotic dynamics occurring in complex biological systems such as recurrent neural networks or ecosystems remains a conceptual challenge. For low-dimensional dynamics...
doi.org
Reposted by Alex van Meegen
david-g-clark.bsky.social
I'll be presenting this at #cosyne2025 (poster 3-50)!

I'll also be giving a talk at the "Collectively Emerged Timescales" workshop on this work, plus other projects on emergent dynamics in neural circuits.

Looking forward to seeing everyone in 🇨🇦!
Reposted by Alex van Meegen
olveczky.bsky.social
Excited to present the latest from the lab out today in Cell www.cell.com/cell/fulltex.... See Thread! 1/8
Reposted by Alex van Meegen
stefanofusi.bsky.social
We always see that 1) neural responses are very diverse 2) the shattering dimensionality is as high as it can be. Now also in an extensive analysis of the IBL dataset. Wonderful collaboration with @lorenzoposani.com, Shuqi Wang, Samuel Muscinelli, Liam Paninski. Many new analyses in this new version
Reposted by Alex van Meegen
engeltatiana.bsky.social
Our new paper with @chrismlangdon is just out in @natureneuro.bsky.social! We show that high-dimensional RNNs use low-dimensional circuit mechanisms for cognitive tasks and identify a latent inhibitory mechanism for context-dependent decisions in PFC data.
www.nature.com/articles/s41...
Reposted by Alex van Meegen
bellecguill.bsky.social
Pre-print 🧠🧪
Is mechanism modeling dead in the AI era?

ML models trained to predict neural activity fail to generalize to unseen opto perturbations. But mechanism modeling can solve that.

We say "perturbation testing" is the right way to evaluate mechanisms in data-constrained models

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