Kelsey Han

cell.comHigh-dimensional structure underlying individual differences in naturalistic visual experienceHan 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...

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Chris Baker

@cibaker.bsky.social

A new method for translating functional brain responses between species - Spatiotemporal Hyperalignment projects shared information into a common representational space Led by @kbraunlich.bsky.social Marianne Duyck with @bevilconway.bsky.social www.biorxiv.org/content/10.6...

biorxiv.orgTranslating functional brain activity between humans and monkeysComparing brain responses across species is essential for identifying models of human cognition and testing theories of brain evolution, but differences in brain size, measurement techniques, and sign...

Kelsey Han reposted

Earl K. Miller

@earlkmiller.bsky.social

The brain uses dimensionality reduction as a built-in feature of its wiring. Network geometry shapes the transformation of task representations across the human cortex www.nature.com/articles/s41... #neuroscience

nature.comNetwork geometry shapes the transformation of task representations across the human cortex - Nature NeuroscienceThe dimensionality of intrinsic brain connectivity systematically shapes how task representations compress and expand across the cortex, and activity flow modeling shows the active role of network geo...

Kelsey Han reposted

Jane Han

@jane-han.bsky.social

Finally the ‘new’ paper in Nature Communications! 🧠🎬 @samnastase.bsky.social @haxbylab.bsky.social Action purpose & social content explain cortical representational geometry better than visual & word-embedding models, even in ventral temporal cortex. www.nature.com/articles/s41... 1/6 🧵👇

nature.comBehaviorally-relevant features of observed actions dominate cortical representational geometry in natural vision - Nature CommunicationsHan et al. show that behavioral judgments of action meaning better capture brain activity than models of semantic and visual content across much of cortex, including the action observation network and...

Kelsey Han reposted

Kathy Garcia

@gkathy.bsky.social

What dimensions organize how we see social interactions? We learn them from 53,000+ human judgments of naturalistic social clips. They explain 2× the variance of pre-labeled annotations & better predict visual cortex, EBA, and pSTS New preprint w @lisik.bsky.social 🧵 osf.io/preprints/ps...

Kelsey Han reposted

Erica Busch

@elbusch.bsky.social

11 June

Our new paper is out this week in Nature Neuroscience! www.nature.com/articles/s41... We built a BCI that works with the brain's natural geometry — and we found that people could learn to play a video game with their brains in <1 hr of training. This efficiency is groundbreaking & here's why:

nature.comHuman learning of noninvasive brain–computer interfaces via manifold geometry - Nature NeuroscienceBusch et al. use nonlinear neural manifolds to help humans gain rapid control over a noninvasive brain–computer interface, allowing them to learn how to play a video game with real-time fMRI neurofeed...

Kelsey Han reposted

Erica Busch

@elbusch.bsky.social

29 May

🎉🎉🎉🎉 I'm thrilled and humbled to share some major updates! (A 🧵 but TLDR: graduated from Yale, joining Sungkyunkwan University in South Korea as an IBS Young Scientist Fellow this summer, and starting as an assistant professor in Vanderbilt's College of Connected Computing in Fall 2027!)

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Hayoung Song

@hayoungsong.bsky.social

23 Mar

Attention fluctuates over time and across contexts—how is this reflected in the brain?🧠 Fitting a dynamical systems model to fMRI data, we show that the geometry of neural dynamics along the attractor landscape reflects changes in attention. Out in @natcomms.nature.com www.nature.com/articles/s41...

nature.comGeometry of neural dynamics along the cortical attractor landscape reflects changes in attention - Nature CommunicationsAttention fluctuates over time and across contexts—how is this reflected in the brain? Fitting a dynamical systems model to fMRI data, Song and colleagues show that the geometry of neural dynamics alo...

Kelsey Han reposted

Alex Williams

@itsneuronal.bsky.social

19 Mar

Cosyne invited me to give a long tutorial (4 hours!) on methods to quantify differences high-d neural recordings across animals, brain regions, deep neural nets, etc. The recording is up on youtube. I hope it inspires more research on this fundamental topic! www.youtube.com/watch?v=n44x...

youtube.comCosyne 2026 - Cosyne Tutorial: Comparative Analysis of Neural Population CodesYouTube video by Cosyne Talks

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Andrew Lampinen

@lampinen.bsky.social

17 Mar

Pleased to share that our paper "Representation Biases: Variance is Not Always a Good Proxy for Importance" is now out as Theory/New Concepts paper in eNeuro! www.eneuro.org/content/13/3... 1/

eneuro.orgRepresentation Biases: Variance Is Not Always a Good Proxy for ImportanceA central approach in neuroscience is to analyze neural representations as a means to understand a system's function, through the use of methods like principal component analysis, regression, and repr...

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The upshot: your subjective experience isn't encoded in a low-dimensional subspace of cortical activity. It emerges from the full high-dimensional geometry of cortical population responses—most of which we've been missing with conventional approaches.

So yes—high-dimensional neural codes do shape behavior. Not only do stimulus representations scale unboundedly, individual differences span the full dimensional capacity of cortical codes. We're only beginning to understand the rich structure that makes each brain unique.

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These neural differences matter! Fine-grained structure in higher dimensions of cortical activity predicts behavioral differences during recall—even after accounting for coarse-scale effects captured by standard methods.

We also found that neural dimensionality is related to the concreteness of each subject’s recollection. Subjects who focus on concrete details, as opposed to abstract aspects of the movies, tend to share more dimensions with others.

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Recent work from our lab revealed the scale-free structure of cortical image representations in large-scale studies of humans and monkeys. Stimulus-related information is distributed across thousands of dimensions, extending far beyond the few dominant components typically studied.

Mick Bonner@mickbonner.bsky.social

Dimensionality reduction may be the wrong approach to understanding neural representations. Our new paper shows that across human visual cortex, dimensionality is unbounded and scales with dataset size—we show this across nearly four orders of magnitude. journals.plos.org/ploscompbiol...

In our new work, we find that the ways individual brains differ are *not* constrained to a few dominant patterns. We find distinct patterns in how individual brains process natural movies along many latent dimensions, and these differences are reliable across different movies.