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Maxence Pajot

@maxencepajot.bsky.social
68 followers 83 following 21 posts

PhD student with Stanislas Dehaene and Yair Lakretz. I’m interested in mathematical cognition and AI

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Maxence Pajot @maxencepajot.bsky.social · 21/09/2026
It's possible yes! We go in more detail in the discussion of the paper, but even if the successes are impressive, models might still lack something to fully model human perception of geometric shapes.
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Maxence Pajot @maxencepajot.bsky.social · 20/09/2026
It's an interesting suggestion! I ran a quick test with the available weights on the quadrilateral task. The DVD seems to improve alignment over the baseline within your pipeline. However all models trained with this pipeline were less aligned with human behavior than the classically trained resnet.
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Maxence Pajot @maxencepajot.bsky.social · 07/09/2026
Thank you!
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Maxence Pajot @maxencepajot.bsky.social · 02/09/2026
Full paper: doi.org/10.1371/jour... Work done at @unicog.bsky.social. Big thanks to co-authors @theomorfoisse.bsky.social, @mathiassablemeyer.bsky.social, Yair Lakretz, @standehaene.bsky.social. 8/8
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Can neural networks model the human perception of geometric shapes?
Author summary Recent neural networks have achieved remarkable success across a wide range of visual tasks, often rivaling or surpassing human performance. Yet, it remains unclear whether these system...
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Maxence Pajot @maxencepajot.bsky.social · 02/09/2026
The third task is the most demanding: matching a photograph with a minimalist drawing of the same item, for instance a fish drawn as an ellipse and a triangle. Humans find this trivial. No model does, although the best ones get close to human performance. 7/8
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Maxence Pajot @maxencepajot.bsky.social · 02/09/2026
In the second task, we go beyond quadrilaterals, looking at the representations of a broader set of 68 shapes. Alignment with humans was again mainly driven by training set size. However, adding symbolic information did bring the best models closer to humans. 6/8
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Maxence Pajot @maxencepajot.bsky.social · 02/09/2026
In the first experiment, we model an outlier detection task on quadrilaterals. Best models now correlate highly with human behaviour, above the symbolic model. Adding symbolic features did not improve alignment. What drives this is training set size, not architecture or number of parameters. 5/8
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Maxence Pajot @maxencepajot.bsky.social · 02/09/2026
We compared human behaviour on three tasks to a wide range of models: CNNs and Vision Transformers, from 20M to 7B parameters, trained on datasets ranging from ImageNet-1k to LAION-2B, using classification, CLIP or DINO. 4/8
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Maxence Pajot @maxencepajot.bsky.social · 02/09/2026
A lot has changed since. Campbell et al. (2024) found that recent large-scale models seem to behave in a more human-like way on geometric tasks. We revisit this, while also looking at the factors driving these abilities. 3/8
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Maxence Pajot @maxencepajot.bsky.social · 02/09/2026
In 2021, Sablé-Meyer et al. showed that vision models did not model human behaviour on quadrilaterals accurately: their representations were in fact closer to those of baboons than of humans. Human behaviour was best captured by a symbolic model, encoding right angles, parallel sides, etc. 2/8
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Maxence Pajot @maxencepajot.bsky.social · 02/09/2026
New AI models now show incredible math skill, solving problems that had stumped mathematicians for years. But what about basic geometric abilities? In our new paper in PLOS Computational Biology, we investigate this in vision models: doi.org/10.1371/jour... 1/8
doi.org
Can neural networks model the human perception of geometric shapes?
Author summary Recent neural networks have achieved remarkable success across a wide range of visual tasks, often rivaling or surpassing human performance. Yet, it remains unclear whether these system...
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Reposted by Maxence Pajot
Lucas Benjamin @lucaswbenjamin.bsky.social · 24/08/2026
Our new paper is now out in @pnas.org! How does the (baby) brain extract regularities from sequences from what-follows-what up to large-scale network structure? What if it all came from a single mechanism? www.pnas.org/doi/abs/10.1...
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Barbu Revencu @barbu-revencu.bsky.social · 12/06/2026
Representations of geometric shapes have syntactic structure w/ @maxencepajot.bsky.social and @standehaene.bsky.social is out & open-access in JEP:General doi.org/10.1037/xge0.... For an overview, see thread below!
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APA PsycNet
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Alireza Karami | علیرضا کرمی @alirezakr.bsky.social · 04/05/2026
Our new study (Debray*, Karami* et al.) explores how the brain encodes basic math concepts (integers, fractions, shapes). Samuel Debray led the 7T fMRI & behavioral work; I led the MEG. @danielavalerio.bsky.social @chrplr.bsky.social @standehaene.bsky.social www.biorxiv.org/content/10.6...
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Maxence Pajot @maxencepajot.bsky.social · 17/07/2025
Definitely, thanks for the suggestion!
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Maxence Pajot @maxencepajot.bsky.social · 15/07/2025
In short: number frequencies show consistent patterns across languages. A simple model grounded in a Language of Thought—recursively using +, ×, and 1—captures these patterns remarkably well. This supports the idea that number concepts are built compositionally in the mind. doi.org/10.1016/j.co...
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Maxence Pajot @maxencepajot.bsky.social · 15/07/2025
With the cumulative model, we get an added benefit: it yields precise hypotheses about the mental representation of each number. For instance, 24 is most likely represented as 4×6, but also as 2×12, 3×8, or the successor of 23—in that order.
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Maxence Pajot @maxencepajot.bsky.social · 15/07/2025
Our model was actually missing a crucial ingredient: approximation. Locutors experience a tradeoff between accuracy of the expressed quantity and length of the expression. Adding a parameter to account for this accurately models the whole curve.
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Maxence Pajot @maxencepajot.bsky.social · 15/07/2025
Fitting our models to the data, we find that both models accurately captured the downward trend as well as some local peaks, yet it failed to do so for decade numbers. Why?
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Maxence Pajot @maxencepajot.bsky.social · 15/07/2025
We developed two models to explain how often a number appears: - Shortest-path: only the simplest construction determines frequency - Cumulative: all valid constructions contribute to frequency, weighted by their complexity Here's how:
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Maxence Pajot @maxencepajot.bsky.social · 15/07/2025
Building on this, we tested a new cognitive model based on a Language of Thought (LoT) introduced by Dehaene et al., 2025. The idea: number concepts are constructed in the mind using simple building blocks—1, +, and ×.
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Maxence Pajot @maxencepajot.bsky.social · 15/07/2025
Some of this isn’t new. Dehaene & Mehler (1992) already showed that number word frequencies follow a ~1/n² law. They suggested that while cultural or environmental factors could explain some of the frequency curve, the psychological organization of number concepts must play a major role.
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Maxence Pajot @maxencepajot.bsky.social · 15/07/2025
Using the Google N-grams database, we looked at the frequency of number words from 1 to 99 in 6 languages. Across the board, we found two patterns: 🔻 Frequency drops with size 📈 Local spikes at certain numbers—especially round ones and those with many small divisors
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Maxence Pajot @maxencepajot.bsky.social · 15/07/2025
Some numbers seem to show up everywhere. Think of 10, 12, 24, 36... Others—like 26 or 34—don’t get the same attention.Why? In our new paper with @standehaene.bsky.social and @mathiassablemeyer.bsky.social, we argue it's because of how the mind builds number concepts. 🧵 doi.org/10.1016/j.co...
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Barbu Revencu @barbu-revencu.bsky.social · 28/02/2025
Preprint alert (link below)! @maxencepajot.bsky.social, @standehaene.bsky.social, and I show that human adults, but not convolutional or transformer networks, encode geometric shapes in hierarchically structured representations. TL;DR: Geometric-shape representations have internal syntax! 1/8
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