The below is a public review Anthropic asked me to write for their new global workspace paper. I recommend at least skimming their paper first.

TLDR:

I think this is a fantastic paper - it presents compelling evidence for some kind of "cognitive space" in models, that is used as a "working memory" for intermediate variables during a forward pass, shows that J-Lens is a useful technique for accessing this space. I believe these key claims.
I believe J-Lens will be a useful (but limited) tool in practice for model forensics, e.g. generating hypotheses about unusual model behaviour during alignment audits.
I discuss my mental models for why a cognitive space should exist, and first principles arguments for why J-Lens should work for accessing it
I assess the paper's evidence that this cognitive space exists, and the paper's evidence that J-Lens is practically useful.
We have replicated the core claims on Qwen 3.6 27B, and also share preliminary evidence of extending this work by finding abstract "interpretative meta-tokens", like Chinese characters for "what does this mean" that seem to activate and play a causal role on processing ambiguous sentences.

What claims is this paper making?

In my opinion this paper makes 4 significant claims:

Scientific claim: There exists a "cognitive space" inside the model, where (some) intermediate variables are stored during a forward pass
Methodological claim: Logit and J-Lens both work for finding this cognitive space, and J-Lens is better
Pragmatic claim: J-Lens is a practically useful interpretability technique, eg for alignment audits
Philosophical claim: This cognitive space is analogous to a global workspace
I think the scientific claim is by far the most interesting, and I am persuaded by it. The paper provides an overwhelming amount of evidence for the existence of this cognitive space - even if I quibbled over many details, there's enough hard-to-fake evidence that clearly something important is going on.
- I already suspected the existence of a cognitive space, so didn't require that much evidence to be convinced, but I think this should be compelling proof even to skeptical observers that something is happening
- However, I am not convinced of all of the fine details argued in the post about the properties of this space (eg section 4) - the evidence and interpretations largely seemed plausible, but I suspect that some is ambiguous eno

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