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.