Matthias Nau

After several years of work, my lab is starting to put out our first papers on learning in a unicellular organism (Stentor coeruleus).

Here we show evidence for a form of associative learning in Stentor:
www.biorxiv.org/content/10.6...

A recent @natneuro.nature.com paper analyzed lesion network mapping and raised concerns about the validity of the method.
See below 👇 for our response.

www.biorxiv.org/content/10.6...

Compact deep neural network models of the visual cortex Nature - Parsimonious deep neural network models can be used for prediction of visual neuron responses.

DNN models of the brain are getting bigger. Are we replacing one complicated system in vivo with another in silico?

In new work, we seek the *smallest* DNN models of visual cortex, balancing prediction with parsimony.

It turns out these compact models are surprisingly small!

rdcu.be/e5H8G

1/7 Can infants recognise the world around them? 👶🧠 As part of the FOUNDCOG project, we scanned 134 awake infants using fMRI. Published today in Nature Neuroscience, our research reveals 2-month-old infants already possess complex visual representations in VVC that align with DNNs.

Amazing. Congratulations, Dileep!

Ida Momennejad, The Ontological Reversal of Computation and the Brain - PhilArchive The Brain Abstracted (2025) critiques treating abstractions in neuroscience as complete explanations of the brain, for their oversimplification and control-orientation. Chirimuuta argues that neurosci...

On the invitation for a commentary on Mazviita Chirimuuta's The Brain Abstracted, I had the pleasure of writing on equating the brain with computation.

The Ontological Reversal of Computation and the Brain

in Philosophy & the Mind Sciences.
Below see what I agree & disagree with in the book.
🧵 1/n

A 2D Gabor-wavelet baseline model out-performs a 3D surface model in scene-responsive cortex Author summary To gain a more complete picture of human visual processing, it is critical to understand the precise format of representations of naturalistic visual scenes. Recent work has approached ...

Excited that this work with @serences.bsky.social and @timbrady.bsky.social is now out! Our Gabor-wavelet model better predicted voxel responses in scene regions than 3D models. Does this mean that scene areas aren’t “for” processing 3D scene structure? NO, we argue. 1/
dx.plos.org/10.1371/jour...

US applications for prestigious European research grants surge Rush for funds to relocate laboratories to Europe is latest sign of a US brain drain.

I've written two @nature.com stories this week looking at whether EU efforts to lure US scientists are working 🧪

They are: the number of US applicants wanting to take up ERC grants has doubled. www.nature.com/articles/d41...

Thrilled to finally share this work! 🧠🔊

Using a new reinforcement-free task we show mice (like humans) extract abstract structure from sound (unsupervised) & dCA1 is causally required by building factorised, orthogonal subspaces of abstract rules.

Led by Dammy Onih!
www.biorxiv.org/content/10.6...

Another good one! :)

Adaptive episodic memory: how multiple memory representations drive behavior in humans and nonhumans | Physiological Reviews | American Physiological Society Episodic memory is a declarative long-term memory of a specific past experience. As such, it is multifaceted, encompassing both the objective and subjective components of that experience. These components can be flexibly represented at different levels of granularity, from precise, context-specific details to generalized, gistlike representations. In this review, we suggest that 1) multiple representations of an episodic memory at different levels of granularity are simultaneously encoded into a memory trace and 2) the relative weighting of these representations determines the extent to which a memory is reconstructed or reproduced at retrieval. We propose that this representational flexibility drives adaptive behavior by prioritizing reconstruction or reproduction depending on the age of the memory, its relationship to prior knowledge, current attentional goals or task demands, and individual differences. Drawing on research in humans and nonhuman animals, we show a close correspondence between psychological and neural representations of a memory across encoding, consolidation, and retrieval. Specifically, we discuss how hippocampal activity in humans and engram formation and activation in rodents support the reproduction of detailed memory representations, whereas schema formation across species, mediated by the medial prefrontal cortex, facilitates reconstruction and generalization to guide behavior. Finally, we consider how species- and individual-level differences shape episodic memory representations. By integrating findings across species, we illustrate how the correspondence between neural and psychological representations enables multiple memory representations to balance stability and flexibility, ultimately driving adaptive behavior.

How do memories guide behaviour?

Multiple memory representations, from detailed to gist-like, let us flexibly reconstruct or reproduce past experiences to behave adaptively across species.

Now out in Physiological Reviews with Morris Moscovitch, Melanie Sekeres & @brianlevine.bsky.social!

Building compositional tasks with shared neural subspaces Nature - The brain can flexibly perform multiple tasks by compositionally combining task-relevant neural representations.

Thrilled that my paper is out in the @nature.com. We explored how the brain builds complex tasks by compositionally combining simpler sub-task representations. The brain flexibly performs multiple tasks by dynamically reusing neural subspaces for sensory inputs and motor actions

rdcu.be/eRVUk

neuroAI comparisons of ANNs to brains do have a range of problems. Even more than I had realized. And I was worried before: www.biorxiv.org/content/10.1...

Our paper is out in @natneuro.nature.com!

www.nature.com/articles/s41...

We develop a geometric theory of how neural populations support generalization across many tasks.

@zuckermanbrain.bsky.social
@flatironinstitute.org
@kempnerinstitute.bsky.social

1/14

Congratulations, Ana! 🎉

High-dimensional structure underlying individual differences in naturalistic visual experience Han and Bonner reveal that individual visual experience arises from high-dimensional neural geometry distributed across multiple representational scales. By characterizing the full dimensional spectru...

Human visual cortex representations may be much higher-dimensional than earlier work suggested, but are these higher dimensions of cortical activity actually relevant to behavior? Our new paper tackles this by studying how different people experience the same movies. 🧵 www.cell.com/current-biol...

What is the brain for? Active inference is widely discussed as a unifying framework for understanding brain function, yet its empirical status remains debated. Our review identifies core predictions across the action-perception cycle and evaluates their empirical support: osf.io/preprints/ps...

Do goal-directed actions minimize prediction error? Together with @haslagter.bsky.social and @fahrenfort.bsky.social I identified falsifiable predictions of active inference and reviewed the extent to which they are supported by empirical results. Read the preprint here: tinyurl.com/2by8k3h6

Episodic memory facilitates flexible decision-making via access to detailed events - Nature Human Behaviour Nicholas and Mattar found that people use episodic memory to make decisions when it is unclear what will be needed in the future. These findings reveal how the rich representational capacity of episod...

Our experiences have countless details, and it can be hard to know which matter.

How can we behave effectively in the future when, right now, we don't know what we'll need?

Out today in @nathumbehav.nature.com , @marcelomattar.bsky.social and I find that people solve this by using episodic memory.

A unifying account of replay as context-driven memory reactivation A context-driven memory model simulates a wide range of characteristics of waking and sleeping hippocampal replay, providing a new account of how and why replay occurs.

Really thrilled that this paper led by @neurozz.bsky.social is now published in its final version in @elife.bsky.social!!

This is a memory-focused (as opposed to RL-focused) account of the detailed characteristics of forward and backward awake and sleep replay!

elifesciences.org/articles/99931

Pupil size reflects moment-to-moment fluctuations in mental imagery, but not (or hardly) individual differences in imagery Previous research has shown that the eyes' pupils are larger when imaging dark as compared to bright objects or scenes. Based on this, it has been claimed that pupil size is a sensitive marker of ment...

🚨 #Preprint alert 🚨 A multilab study led by Claire Vanbuckave investigated whether the strength of pupil responses to imagined brightness/ darkness reflect differences in vividness of mental imagery. We found … 👇 1/3 🧵 #psychology #aphantasia #pupillometry #mentalimagery
doi.org/10.64898/202...

The Mythology Of Conscious AI | NOEMA Why consciousness is more likely a property of life than of computation and why creating conscious, or even conscious-seeming AI, is a bad idea.

4/ The Mythology of Conscious AI is published now in @noemamag.com (many thanks to Tami Abdollah @latams.bsky.social for her patient & peerless editing) www.noemamag.com/the-mytholog...

For 15(!) years I’ve been teaching introductory #MRI to grad students, and struggled to find a textbook for a wide variety of backgrounds. I'm happy to share an online textbook I created, fully open source (including code for generating figures and plots shown):
larsonlab.github.io/MRI-educatio...

Amazing resource right here! 👇

“These findings provide clear evidence that data collected on MTurk simply cannot be trusted.”

This paper had a pretty shocking headline result (40% of voxels!), so I dug into it, and I think it is wrong. Essentially: they compare two noisy measures and find that about 40% of voxels have different sign between the two. I think this is just noise!

A meta-analysis of studies using Tolman’s sunburst maze suggests poor replicability and little evidence for shortcutting. Ouch! Definitely relevant reading for anyone interested in cognitive maps! 👇

"All intelligence is collective intelligence: each of us consists of a huge number of cells working together to generate a coherent cognitive being with goals, preferences, & memories that belong to the whole and not to its parts"

@drmichaellevin.bsky.social
paper pubmed.ncbi.nlm.nih.gov/37204591/

Great new tool for tracking animal behavior by @rijacobsen.bsky.social & @octoscience.bsky.social et al! 👇🐙

Rethinking the centrality of brain areas in understanding functional organization Nature Neuroscience - Parcellation of the cortex into functionally modular brain areas is foundational to neuroscience. Here, Hayden, Heilbronner and Yoo question the central status of brain areas...

New Perspective from myself, Sarah Heilbronner and @myoo.bsky.social . “Rethinking the centrality of brain areas in understanding functional organization” in Nature Neuroscience. 🧵

rdcu.be/eVZ1A