Subtext Visualizes Silent Words in Model Thinking

TheOnlyVibemaster · reddit · 2026-07-07

Anthropic released its J-space / global workspace research, revealing that a small number of "silent words" emerge internally (dozens of concepts, accounting for <10% of activations) for reasoning and reporting. They open-sourced a Jacobian lens measurement tool, and Neuronpedia provides a pre-fitted lens for Qwen. Leveraging this, the author built Subtext: running qwen3.5-4B in bf16 on a single 12GB GPU, reading 9 layers of the lens token-by-token. It allows real-time visualization of the model's internal judgments as it reads messages and generates replies (e.g., when reading '12+5=1', 'incorrect' lights up before any reply token is output). The speed matches generation speed, and top-5 results have been verified layer-by-layer against Anthropic's reference implementation.

Related event: Anthropic Discovers Global Workspace Inside Claude(102 posts)→

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