Benno Krojer

Benno Krojer

@bennokrojer.bsky.social

AI PhDing at Mila/McGill. Happily residing in Montreal 🥯❄️ Academic stuff: language grounding, vision+language, interp, rigorous & creative evals, cogsci Other: many sports, urban explorations, puzzles/quizzes bennokrojer.com

2.6K followers1K following1.8K posts

If I had to summarize this paper in one philosophical question: Why do we call some things by the same name and others by different names? Related to old philosophy of logic/language is Quine's work (1960): en.wikipedia.org/wiki/Inscrut...

en.wikipedia.orgInscrutability of reference - Wikipedia
Benno Krojer@bennokrojer.bsky.social

My first last-author paper is out! If you saw this dog below and someone showed you the second image, would you consider them the same word/concept? (more examples in Ada's thread) We study if VLMs agree with humans on this and revisit old questions around shape vs. texture bias in vision

My first last-author paper is out! If you saw this dog below and someone showed you the second image, would you consider them the same word/concept? (more examples in Ada's thread) We study if VLMs agree with humans on this and revisit old questions around shape vs. texture bias in vision

Ada@adadtur.bsky.social

Super excited to finally announce my latest research “Would you still call this Dax? Novel Visual References in VLMs and Humans”! We studied how vision-language models (VLMs) adopt new visual concepts and map them to language compared to humans, and found that…

Benno Krojer reposted

I'll be presenting OvertonBench at #ICLR2026 in Rio later this week! 📍Sat, Apr 25, 10:30am in Pavilion 4 (#4109) Please DM me if you'd like to chat about pluralistic / value alignment, societal impacts, epistemology, fairness, evals, etc

Elinor@elinorpd.bsky.social

There's been a lot of excitement about pluralistic value alignment 🌈 — AI that reflects the full range of human perspectives But no formal way to benchmark whether we're actually making progress. 🤔 Introducing 𝐎𝐕𝐄𝐑𝐓𝐎𝐍𝐁𝐄𝐍𝐂𝐇. 🎉Accepted to #ICLR2026 1/n 🧵

I'll be at ICLR! Will present our LatentLens paper at the Re-Align workshop and happy to chat (ideally at the beach 🏖️)

Benno Krojer@bennokrojer.bsky.social

🚨New paper Are visual tokens going into an LLM interpretable 🤔 Existing methods (e.g. logit lens) and assumptions would lead you to think “not much”... We propose LatentLens and show that most visual tokens are interpretable across *all* layers 💡 Details 🧵

What are your favorite papers that can serve as excellent examples how to write great scientific paper, present results, great figures, make it engaging and easy to follow? Doesn't necessarily have to be the most cited or impactful ones

Benno Krojer reposted

Replying to @elinorpd.bsky.social

Inspired by @bennokrojer.bsky.social, we included a Behind the Scenes section 🎬 The goal is to make science more transparent 🔍, share lessons learned 🧠, and provide a more realistic lens on the research journey 👣 8/ bsky.app/profile/benn...

Benno Krojer@bennokrojer.bsky.social

For every one of my papers, I try to include a "Behind the Scenes" section I think this paper in particular has a lot going on behind the scenes; from lessons learned to personal reflections let me share some

Benno Krojer reposted

🚨New Paper!🚨 How do reasoning LLMs handle inferences that have no deterministic answer? We find that they diverge from humans in some significant ways, and fail to reflect human uncertainty… 🧵(1/10)

People often say (myself too): Interpretability on AI is so much easier than neuroscience! We can inspect everything and even retrain (vs carefully poke a little into the brain)! One big advantage in neuroscience I often forget: We're quite literally *inside* the thing we're studying

Another way to put it: With ai systems, we'll never have such privileged access to latents than with brains (albeit just our own, so depends how much you think we're all the same roughly)

People often say (myself too): Interpretability on AI is so much easier than neuroscience! We can inspect everything and even retrain (vs carefully poke a little into the brain)! One big advantage in neuroscience I often forget: We're quite literally *inside* the thing we're studying

The flip side: With ai systems it's still very much unclear which of our human intuitions apply (anthropomorphizing) and when they're a completely different beast that require fully new theories of cognition

People often say (myself too): Interpretability on AI is so much easier than neuroscience! We can inspect everything and even retrain (vs carefully poke a little into the brain)! One big advantage in neuroscience I often forget: We're quite literally *inside* the thing we're studying

You can now "pip install latentlens" 🔨 It comes with: * pre-computed embeddings for several popular LLMs and VLMs * a txt file with sentences describing WordNet concepts, which we recommend as a standard corpus to get embeddings from * ... Try it out and let us know what we can improve!

Benno Krojer@bennokrojer.bsky.social

🚨New paper Are visual tokens going into an LLM interpretable 🤔 Existing methods (e.g. logit lens) and assumptions would lead you to think “not much”... We propose LatentLens and show that most visual tokens are interpretable across *all* layers 💡 Details 🧵

You can now "pip install latentlens" 🔨 It comes with: * pre-computed embeddings for several popular LLMs and VLMs * a txt file with sentences describing WordNet concepts, which we recommend as a standard corpus to get embeddings from * ... Try it out and let us know what we can improve!

Benno Krojer@bennokrojer.bsky.social

🚨New paper Are visual tokens going into an LLM interpretable 🤔 Existing methods (e.g. logit lens) and assumptions would lead you to think “not much”... We propose LatentLens and show that most visual tokens are interpretable across *all* layers 💡 Details 🧵

Finally getting into this classic Let's see if by the end I'll have a clearer idea what type of science some fields of AI are, like interpretability What are our paradigms?

Benno Krojer reposted

What does it mean for visual tokens to be "interpretable" to LLM? And how to we measure it? These, and many more pressing questions are addressed! Introducing LatentLens -- a new, more faithful tool for interpretability! Honoured to have collaborated with @bennokrojer.bsky.social on this!

Benno Krojer@bennokrojer.bsky.social

🚨New paper Are visual tokens going into an LLM interpretable 🤔 Existing methods (e.g. logit lens) and assumptions would lead you to think “not much”... We propose LatentLens and show that most visual tokens are interpretable across *all* layers 💡 Details 🧵

For every one of my papers, I try to include a "Behind the Scenes" section I think this paper in particular has a lot going on behind the scenes; from lessons learned to personal reflections let me share some

Benno Krojer@bennokrojer.bsky.social

🚨New paper Are visual tokens going into an LLM interpretable 🤔 Existing methods (e.g. logit lens) and assumptions would lead you to think “not much”... We propose LatentLens and show that most visual tokens are interpretable across *all* layers 💡 Details 🧵

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For every one of my papers, I try to include a "Behind the Scenes" section I think this paper in particular has a lot going on behind the scenes; from lessons learned to personal reflections let me share some

Benno Krojer@bennokrojer.bsky.social

🚨New paper Are visual tokens going into an LLM interpretable 🤔 Existing methods (e.g. logit lens) and assumptions would lead you to think “not much”... We propose LatentLens and show that most visual tokens are interpretable across *all* layers 💡 Details 🧵

View full thread

For every one of my papers, I try to include a "Behind the Scenes" section I think this paper in particular has a lot going on behind the scenes; from lessons learned to personal reflections let me share some

Benno Krojer@bennokrojer.bsky.social

🚨New paper Are visual tokens going into an LLM interpretable 🤔 Existing methods (e.g. logit lens) and assumptions would lead you to think “not much”... We propose LatentLens and show that most visual tokens are interpretable across *all* layers 💡 Details 🧵

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Then the project went "off-track" for a while, partially because we didn't question our assumptions enough: We just assumed visual tokens going into an LLM would not be that interpretable (based on the literature and our intuition) But we never fully tested it for many weeks!

For every one of my papers, I try to include a "Behind the Scenes" section I think this paper in particular has a lot going on behind the scenes; from lessons learned to personal reflections let me share some

Benno Krojer@bennokrojer.bsky.social

🚨New paper Are visual tokens going into an LLM interpretable 🤔 Existing methods (e.g. logit lens) and assumptions would lead you to think “not much”... We propose LatentLens and show that most visual tokens are interpretable across *all* layers 💡 Details 🧵

This will be my last paper of the phd, can't believe it's been almost 5 years! It is the work i am most proud of and believe has the most potential. Feels right to wrap it up with this one

Benno Krojer@bennokrojer.bsky.social

🚨New paper Are visual tokens going into an LLM interpretable 🤔 Existing methods (e.g. logit lens) and assumptions would lead you to think “not much”... We propose LatentLens and show that most visual tokens are interpretable across *all* layers 💡 Details 🧵

View full thread

This will be my last paper of the phd, can't believe it's been almost 5 years! It is the work i am most proud of and believe has the most potential. Feels right to wrap it up with this one

Benno Krojer@bennokrojer.bsky.social

🚨New paper Are visual tokens going into an LLM interpretable 🤔 Existing methods (e.g. logit lens) and assumptions would lead you to think “not much”... We propose LatentLens and show that most visual tokens are interpretable across *all* layers 💡 Details 🧵

🚨New paper Are visual tokens going into an LLM interpretable 🤔 Existing methods (e.g. logit lens) and assumptions would lead you to think “not much”... We propose LatentLens and show that most visual tokens are interpretable across *all* layers 💡 Details 🧵

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Broader reflections: Are embedding spaces from diff modalities structurally similar, as the Platonic Representation Hypothesis suggests? Are LLMs so good at processing vision because pre-training induced an implicit physical world model? Multimodal interpretability is getting a bigger topic!

We will keep working after this initial release, making latentlens as accessible as possible to other researchers and improving the code base We are optimistic latentlens can be used beyond visual inputs, and aim to make our codebase flexible for broader applications Share your feedback or ideas!

🚨New paper Are visual tokens going into an LLM interpretable 🤔 Existing methods (e.g. logit lens) and assumptions would lead you to think “not much”... We propose LatentLens and show that most visual tokens are interpretable across *all* layers 💡 Details 🧵

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Takeaways: We, the authors, were genuinely surprised to find such systematically high interpretability Recently people started using logit lens to study visual tokens in LLMs. We encourage the community to try out LatentLens next time, even beyond visual processing (any latent LLM representation)

🚨New paper Are visual tokens going into an LLM interpretable 🤔 Existing methods (e.g. logit lens) and assumptions would lead you to think “not much”... We propose LatentLens and show that most visual tokens are interpretable across *all* layers 💡 Details 🧵

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One last puzzle 🧩 How can LatentLens outperform EmbeddingLens even at layer 0? Our hypothsis: Visual tokens arrive already packaged in a semantic format Concretely: An input visual token might have the highest similarity with text representations at e.g. LLM layer 8 We call this "Mid-Layer Leap"

🚨New paper Are visual tokens going into an LLM interpretable 🤔 Existing methods (e.g. logit lens) and assumptions would lead you to think “not much”... We propose LatentLens and show that most visual tokens are interpretable across *all* layers 💡 Details 🧵

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How do we quantity whether a visual token is interpretable? We capture in a VLM judge what a human would intuitively do: Look at the top-5 NNs and the part in the image from which the visual token came from and answer: Are these top-5 NNs semantically related to the image or the part of the image?

With this automatic metric, we can compare LogitLens, EmbeddingLens and LatentLens on 9 model combinations that we train (3 vision encoders x 3 LLMs) The two baselines are a mixed bag: some models and some layers are okay but many others not LatentLens shows high interpretability across the board

🚨New paper Are visual tokens going into an LLM interpretable 🤔 Existing methods (e.g. logit lens) and assumptions would lead you to think “not much”... We propose LatentLens and show that most visual tokens are interpretable across *all* layers 💡 Details 🧵

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LatentLens in a nutshell: Instead of an LLM's fixed vocabulary (eg embedding matrix), we propose contextual representations as our pool of nearest neighbors → e.g. the representation of “dog” in “my brown dog” at some layer N

This might sound abstract, so here are some examples We can see: a) LatentLens makes visual tokens interpretable at all layers b) it has no issues with single-token results like logit lens and provides detailed full sentences! (no training or tuning involved)

🚨New paper Are visual tokens going into an LLM interpretable 🤔 Existing methods (e.g. logit lens) and assumptions would lead you to think “not much”... We propose LatentLens and show that most visual tokens are interpretable across *all* layers 💡 Details 🧵

Building a VLM can be surprisingly simple: You keep both the LLM and vision encoder frozen, you just train a small MLP that projects into the LLM embedding space as prefixes. That’s it 😮 But how and why does that work? How do visual tokens relate to language, i.e. do they have interpretable NNs?

Benno Krojer reposted

The visual world is composed of objects, and those objects are composed of features. But do VLMs exploit this compositional structure when processing multi-object scenes? In our 🆒🆕 #ICLR2026 paper, we find they do – via emergent symbolic mechanisms for visual binding. 🧵👇