Or Shafran retweeted
Presenting EMBER tomorrow at #EMNLP2026! 🔥
📍Hall H · Session B· 4:00 PM
Come chat about concept erasure in LLMs, or stop by to say hi (and wish me a happy birthday! 🎈🎂)
New Preprint📢
Removing knowledge from LLMs is hard. Preventing models from relearning it is even harder.
In our new paper with @megamor2 and @OrShafran, we show that existing erasure methods have a blind spot: token embeddings.
The solution? EMBER🔥
🧵👇
Here for 40 hours! 🇭🇺 #EMNLP2026
Will be joining the plenary panel tomorrow, then presenting work with @dhgottesman and @ClaraSuslik on understanding and erasing knowledge representations in LLMs. Come say hi!
dhgottesman.github.io/LMEnt/
arxiv.org/abs/2606.03695
Or Shafran retweeted
Replying to @YNikankin @COLM_conf
xitter.cf/YNikankin/status/20665…
I'll be presenting our work on internal representations of step importance in reasoning models (Session 6, Imperial#70), come by to chat about interp in reasoning and other large-scale setups
New preprint: 🔥 Latent Information Feedback Transformers (LIFT) 🔥
Information in LM generation propagates downward (high to low layers) only through the decoded token, creating a bottleneck. Removing it via state propagation makes the model recurrent, which is not scalable for training.
Can we teach LMs to propagate state while keeping pretraining fully parallel? YES!
LIFT is a Transformer-based architecture + teacher-supervised training approach that enables Transformer LMs to exploit deep-to-shallow feedback, while keeping training parallel.
LIFT models consistently outperform standard Transformers and baselines on language modeling, downstream reasoning tasks, and procedural tasks under a token-matched budget, while being on par with or ahead of compute-matched Transformers. LIFT also outperforms Transformers trained on 8x more data on a state-tracking task, even when trained with the states of a Transformer that fails it!
Work by the amazing @TiroshDor and @AmosaurusRex
Paper: arxiv.org/abs/2609.38149
Detailed post + visualizations + code + models coming soon!
Three papers from our lab at #NeurIPS2026, spanning LLM reasoning faithfulness, belief formation, and interpretability of MoEs:
⭐ Faithfulness Metrics Don't Measure Faithfulness: A Meta-Evaluation with Ground Truth
arxiv.org/abs/2605.25052
We introduce a benchmark for CoT faithfulness metrics, and find that existing metrics are either close to random or prohibitively expensive to run
@GurYoav @anmarasovic
⭐ Indications of Belief-Guided Agency and Meta-Cognitive Monitoring in Large Language Models
arxiv.org/abs/2602.02467
An interdisciplinary collaboration applying the HOT-3 indicator of consciousness to LLMs using interpretability tools, revealing surprising patterns in belief formation and action selection in LLMs
@noam_steinmetz @GoldsteinYAriel @Liad_Mudrik
⭐ Routers Learn the Geometry of Their Experts: Geometric Coupling in Sparse Mixture-of-Experts
arxiv.org/abs/2605.12476
We find a geometric coupling between routers and their corresponding experts in MoEs, explaining how routers form assignments that support an effective division of labor
@sageaarc @noyahochwald
Or Shafran retweeted
New paper! 🫡
We introduce Matryoshka Attribution, a new attribution method which uses gradient descent to find which parts of a neural network are responsible for a behaviour.
MAttr is #1 on the Mechanistic Interpretability Benchmark by a wide margin (2.9× the runner up).
Or Shafran retweeted
Silico, the platform for ambitious AI research, is publicly available today.
AI is advancing fast. The tools to understand it need to advance even faster. Silico lets you interpret and train your models at frontier scale.
Learn more + get access 🧵
Excited to present today at ICML our work:
From Directions to Regions
where we show that LLM activations are better understood not as isolated directions, but as local low-rank geometries — and introduce an unsupervised method to uncover them.
📍 Thu, July 9 · Session 8 · 17:00–18:45 · Poster 3409
Also I’ll be around all week, happy to chat or grab coffee. Feel free to reach out!
Or Shafran retweeted
Our work on Block-Sparse Featurizer is out 🧊 :)
We revive an old idea from the structured sparsity literature and use it to carve activation space into meaningful regions.
It's a first concrete answer to the question our concept manifolds work left open ! :)
I’m excited to be at #ACL2026 today presenting our paper on how matrix factorization can reveal compositional groups of neurons and hierarchies in MLPs!
📍 If you’re around, stop by our poster in Session C, 16:00–17:30. I’d love to chat!
Here we go! ✈️ 🇺🇸🇰🇷 If you're attending #ACL2026 and/or #ICML2026 check out recent work from our group with collaborators:
📍Jul 5 14:00-15:30: Matan will present his TACL work "Universal Jailbreak Suffixes Are Strong Attention Hijackers" @matanbt @mahmoods01
arxiv.org/abs/2506.12880
📍Jul 5 16:00-17:30: My student Or will show how matrix factorization can reveal compositional neuron groups and hierarchies in MLPs. @OrShafran
arxiv.org/abs/2506.10920
📍Jul 6 9:00-10:30: Tomer will talk about "MoNaCo: More Natural and Complex Questions for Reasoning Across Dozens of Documents" @TomerWolfson
arxiv.org/abs/2508.11133
📍Jul 7 14:00-15:45: Hadas will present our position: "Interpretability Can Be Actionable" @OrgadHadas
arxiv.org/abs/2605.11161
(will also appear at the MI workshop)
📍Jul 8 10:30-12:15: I will be presenting a position work with @_galyo and @ymatias on metacognition as a way to move beyond hallucinations
arxiv.org/abs/2605.01428
📍Jul 9 17:00-18:45: Or (after a transpacific flight from ACL) will present MFA: an unsupervised approach to disentangle representations of LLMs at scale using local geometry @OrShafran
arxiv.org/abs/2602.02464
(will also appear at the MI workshop)
Or Shafran retweeted
New Preprint📢
Removing knowledge from LLMs is hard. Preventing models from relearning it is even harder.
In our new paper with @megamor2 and @OrShafran, we show that existing erasure methods have a blind spot: token embeddings.
The solution? EMBER🔥
🧵👇
What's in a neuron? 💫 (an atypically long, almost personal post)
Neurons in LMs have always been a fascinating object to study. I've been studying them since 2020, viewing them as key-value memory cells, analyzing what they capture in vocabulary space, and how they compose together to form features.
arxiv.org/abs/2012.14913
arxiv.org/abs/2203.14680
arxiv.org/abs/2501.08319
arxiv.org/abs/2506.10920
But many neurons still remain opaque! They do many things.
Our recent work led by @AsafAvrahamy tackles this challenge by decomposing neuron weights in vocabulary space. We do this by taking the neuron weight vector and learning different ways to rotate it (just a bit) to reveal monosemantic vocabulary channels that it captures. The nice thing about our method ROTATE is that it's data-free and super efficient, relying only on vocabulary kurtosis as a search signal.
I've been thinking about this idea since 2024, proposed it to multiple students, but only Asaf was brave enough to take this ;)
Very happy with the final outcome. Check out the paper! 👇
arxiv.org/abs/2604.06005
Or Shafran retweeted
Can we tell when LLMs are being unfaithful in their chains of thought?
We evaluated 8 methods claiming to do this, and found that most perform near chance!
But evaluating this requires us to have ground-truth labels for CoT faithfulness. How can we obtain these?
Or Shafran retweeted
1/ New preprint!
Linear directions are everywhere in mech interp. But a bag of linear directions fails to capture meaningful structure! Could there be more going on?
We revisit OthelloGPT, which is known to have linear representations but is trained in a highly structural domain of the board game Othello.
Originally, @NeelNanda5 and I found 192 linear directions (64 squares x 3 colors) that can decode the entire board-state.
In this work we use tensor product representation probes (TPRs) to decompose these linear directions into role (board) embeddings, filler (color) embeddings, and a binding matrix that compose the two to reconstruct board-state (see last tweet for technical details).
(Note that this does NOT mean the model has a separate board / color subspace. This is not our claim - rather, a set of linear directions can be factorized into structurally meaningful components.)
MFA (Mixture of Factor Analyzers) is a new unsupervised approach to disentangle representations of LLMs at scale, using local geometry
MFAs outperform large-scale SAEs in localization and steering while providing interpretable decompositions
To be presented at #ICML2026 🇰🇷
Code and trained MFAs are available at:
github.com/ordavid-s/decompo…
Still using SAEs?
It's time to move on from dictionary learning to✨local geometry✨
xitter.cf/OrShafran/status/20194…
@OrShafran Shaked Ronen @OmriFahn @ravfogel @atticus_geiger
Or Shafran retweeted
😻New preprint! As an interp researcher, I often ask “why did the model attend to this token?” We study this by decomposing the query-key (QK) space into interpretable low-rank subspaces. When these subspaces of Qs and Ks align, the model produces high attention scores.
1/N
It's time to look past dictionary learning for decomposing LM activations.
What happens when we instead leverage local geometry?
We find a natural region-based decomposition that yields better steering and localization 🧵 1/
Fine-grained Steering 🏎️
We often see a causal split: 1️⃣ Centroids promote broad topics (e.g., "Superheroes"). 2️⃣ Local variation captures specific sub-concepts (e.g., "Batman" vs. "Superman"). 7/
MFA offers a new lens on activation decomposition, shifting the focus from fitting global directions to uncovering the local geometry that actually organizes model behavior. 8/
🔗 Paper: arxiv.org/pdf/2602.02464v1
🔗 Code and MFA models: github.com/ordavid-s/decompo…























