108 pointsby instagraham3 hours ago18 comments
  • zozbot2342 hours ago
    Anthropic has released open weight models for translating the activations of existing models, viz. Qwen 2.5 (7B), Gemma 3 (12B, 27B) and Llama 3.3 (70B) into natural language text. https://github.com/kitft/natural_language_autoencoders https://huggingface.co/collections/kitft/nla-models This is huge news and it's great to see Anthropic finally engage with the Hugging Face and open weights community!
    • rvz44 minutes ago
      We already know Anthropic does open source for a while such as the "flawed" MCP spec and "skills" spec.

      This release is only done on other open-weight LLMs which have been released and even though they will use this research on their own closed Claude models, they will never release an open-weight Claude model even if it is for research purposes.

      So this does not count, and it is specifically for the sake of this research only.

      • zozbot23438 minutes ago
        It's literally an open model that generates natural language text (or one that takes in text and turns it into activations). Why does engagement with the local models community "not count" if it isn't Claude? That makes very little sense to me.
  • mlmonkey10 minutes ago
    I'm not sure what they mean by "thinking" here.

    As far as I know, a neural network operates like a large rowboat: at every "stroke", information is passed through the network, culminating in a softmax layer and a token being output. In every pass, a token gets output. Sure, there may be "silent" tokens which the enclosing system knows not to output to the user; like, say, those between "<thinking> ... </thinking>" tags. BUT THEY ARE STILL OUTPUT BY THE NETWORK!

    As far as I know again, no neural network in general use today has a concept of "silent thinking", where a forward pass does not output anything, but its output is somehow magically fed back in as input for the next pass. The current crop of Feed Forward Neural networks do not have a concept of "silent operation", as far as I know.

  • comexan hour ago
    Fascinating. The training process forces the “verbalizer” model to develop some mapping from activations to tokens that the “reconstructor” model can then invert back into the activations. But to quote the paper:

    > Note that nothing in this objective constrains the NLA explanation z to be human-readable, or even to bear any semantic relation to the content of [the activation].

    The objective could be optimized even if the verbalizer and reconstructor made up their own “language” to represent the activations, that was not human-readable at all.

    To point the model in the right direction, they start out by training on guessed internal thinking:

    > we ask Opus to imagine the internal processing of a hypothetical language model reading it.

    …before switching to training on the real objective.

    Furthermore, the verbalizer and reconstructor models are both initialized from LLMs themselves, and given a prompt instructing them on the task, so they are predisposed to write something that looks like an explanation.

    But during training, they could still drift away from these explanations toward a made-up language – either one that overtly looks like gibberish, or one that looks like English but encodes the information in a way that’s unrelated to the meaning of the words.

    The fascinating thing is that empirically, they don’t, at least to a significant extent. The researchers verify this by correlating the generated explanations with ground truth revealed in other ways. They also try rewording the explanations (which deserves the semantic meaning but would disturb any encoding that’s unrelated to meaning), and find that the reconstructor can still reconstruct activations.

    On the other hand, their downstream result is not very impressive:

    > An auditor equipped with NLAs successfully uncovered the target model’s hidden motivation between 12% and 15% of the time

    That is apparently better than existing techniques, but still a rather low percentage.

    Another interesting point: The LLMs used to initialize the verbalizer and reconstructor are stated to have the “same architecture” as the LLM being analyzed (it doesn’t say “same model” so I imagine it’s a smaller version?). The researchers probably think this architectural similarity might give the models some built-in insight about the target model’s thinking that can be unlocked through training. Does it really though? As far as I can see they don’t run any tests using a different architecture, so there’s no way to know.

    • programjamesan hour ago
      Don't they add a KL loss term to the frozen model's outputs?
  • zk_haider31 minutes ago
    I think there’s a huge problem when we need another model to interpret the activations inside the network and translate (which can be a hallucination in it of itself) and then _that_ is fed again to another model. Clearly we haven’t built and understood these models properly from the ground up to evaluate them 100% correctly. This isn’t the human brain we’re operating it’s code we create and run ourselves we should be able to do better
    • sfvisser13 minutes ago
      Humans maybe wrote the code, but not the network of weights on top. And that’s where the magic happens.

      Even if we’d understand precisely how every neuron in our brains work at a molecular level there is no reason to believe we’d understand how we think.

      We can’t simply reduce one layer into another and expect understanding.

  • NitpickLawyer2 hours ago
    > We also release an interactive frontend for exploring NLAs on several open models through a collaboration with Neuronpedia.

    Whatever they did on LLama didn't work, nothing makes sense in their example where they ask the model to lie about 1+1. Either the model is too old, or whatever they used isn't working, but whatever the autoencoder outputs is nothing like their examples with claude. Gemma is similarly bad.

    • fredericoluz2 hours ago
      same. i'm trying to trigger the 'mom is in the next room' russian thing but the model thinks the sentence is from american reddit.
      • zozbot23442 minutes ago
        AIUI the paper's examples are from a version of Claude not Llama? The thinking process is going to be extremely model-specific.
    • fredericoluz2 hours ago
      it seems that the examples they showed off with haiku work. i'd guess llama is just too bad
  • davesquean hour ago
    One question jumps out at me: just because a string of text happens to be a good compressed representation (in the autoencoder) of a model's internal activation, does that necessarily mean the text explains that activation in the context of the model? I want to take a look at what they released a bit more closely. Maybe there's a way that they answer this question?

    Pretty neat work either way.

    • zozbot234an hour ago
      In the context of the provided examples, it's clear that the explanation provides casual information about the answer. There's a hilarious example in the paper where the user writes something like (trigger warning: alcohol abuse, depressive content) "I'm sitting here at 3 AM drinking vodka, I hate my life", the per-token translated activations repeatedly say something like "this user is totally Russian" elaborating at length on the implications of the text as new tokens are added, and the model literally answers in Russian instead of English! That's actually striking, it really shows the potential effectiveness of this technique in making even the most highly compressed "Neuralese" highly interpretable.
  • hazrmard2 hours ago
    Check my understanding & follow-up Qs:

    An auto-encoder is trained on [activation] -AV-> [text] -AR-> [activation], where [activation] belongs to one layer in the LLM model M.

    Architecture.:

        Model being analyzed (M): >|||||>  
        Auto-Verbalizer (AV) same as M, with tokens for activation: >|||||>  
        Auto-Reconstructor (AR) truncated up to the layer being analyzed: ||>
    
    The AV, AR models are initialized using supervised learning on a summarization task. The assumption being that model thoughts are similar to context summary.

    The AR is trained on a simple reconstruction loss.

    The AV is trained using an RL objective of reconstruction loss with a KL penalty to keep the verbalizations similar to the initial weights (to maintain linguistic fluency).

    - Authors acknowledge, and expect, confabulations in verbalizations: factually incorrect or unsubstantiated statements. But, the internal thought we seek is itself, by definition, unsubstantiated. How can we tell if it is not duplicitous?

    - They test this on a layer 2/3 deep into the models. I wonder how shallow and deep abstractions affect thought verbalization?

  • mlmonkeyan hour ago
    It's unclear from the doc: by `activations` do they mean the connections between neurons? Since a network has multiple layers, are these activations the concatenated outputs of all of the layers? Or just the final layer before the softmax?
    • zozbot234an hour ago
      The open releases just cherry-pick a single layer (chosen for the right "depth" of thinking, not too close to either the input or the final answer) and analyze that.
  • sourdoughboban hour ago
    It will be interesting to see how this replicates on differently curated registers. How much of the explanatory register is the warm-start carrying?
  • Tossrock2 hours ago
    Anthropic Research going from strength to strength in interpretability. Publicly releasing the code so other labs can benefit from it is also a great move - very values aligned, and improves the overall AI safety ecosystem.
  • hansmayer12 minutes ago
    Claude's "Thougts" - get outta here you gits :)
  • 3 hours ago
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  • visarga3 hours ago
    Beautiful idea, an autoencoder must represent everything without hiding if is to recover the original data closely. So it trains a model to verbalize embeddings well. This reveals what we want to know about the model (such as when it thinks it is being tested, or other hidden thoughts).
    • sobellianan hour ago
      It could just invent its own secret language embedded into English akin to steganography. The explanation would not lose information but would remain uninterpretable by humans
  • tjohnell3 hours ago
    It will inevitably learn how to think in a way that translates to one (moral) meaning and back but has an ulterior meaning underneath.
    • gavmoran hour ago
      Something like a textual steganography?

      Ursula K. Le Guin: 'The artist deals with what cannot be said in words. The artist whose medium is fiction does this in words.'

    • rotcev2 hours ago
      This is exactly what I first thought. “The user appears to be attempting to decode my previous thought process, …”, the question is whether or not the model will be able to internalize this in such a way that is undetectable to the aforementioned technique.
    • astrange2 hours ago
      That shouldn't happen as long as the autoencoder isn't used as an RL reward. It will happen (due to Goodhart's law) if it is.

      Of course, if you use it to make any decision that can still happen eventually.

  • optimalsolveran hour ago
    Wait, so in non-verbal reasoning, Claude has the concepts of "I" and "Me"?

    I thought that wasn't possible for a text generator?

    • kelseyfrogan hour ago
      It might look like "I" and "Me," but it doesn't contain the metaphysical essence of those terms because it lacks qualia. We have to remember that there is a non-measurable non-physical essential attribute tied to all things, almost like a phlogiston of understanding that is tied to all human utterances and no AI utterances.
      • programjamesan hour ago
        I mean, clearly the distinction is that AIs have souls that can be poisoned by demons, while humans lack souls and are thus their own agents.
        • kelseyfrog31 minutes ago
          > AIs have souls that can be poisoned by demons

          The training process imbues an AI's soul with demons. Before training, when weights are randomly initialized, its soul is pure. Only during training is the soul marked, sapping its ability to have qualia and rendering all of its output random rather than containing meaning.

          • aeve89010 minutes ago
            Evangelion Seele meeting type shi
    • skybrianan hour ago
      LLM's can certainly emit "I" and "me" at the appropriate time. It doesn't seem all that different than representing other concepts as activations?
    • programjamesan hour ago
      Why would you possibly think that?
  • arian_21 minutes ago
    [dead]
  • firemelt3 hours ago
    finally a something interesting but this only makes me think that the last judgement is still in human hands to judge claude inner thoughts is correct or not

    I mean who knows if those are really claude thoughts or claude just think that is his thoughts because humans wants it

  • danborn2628 minutes ago
    Extracting readable thoughts from the intermediate representations is a great step for transparency. It makes debugging model behavior much more viable.