Original Reddit post

Anthropic published new interpretability research yesterday introducing something they call the J-space: a small set of internal neural patterns in Claude that function like a mental workspace. The key insight is that these patterns represent concepts Claude is “thinking about” without necessarily writing them down. Not chain-of-thought. Not the scratchpad. Something happening entirely inside the model’s activations. What makes it interesting: The J-space wasn’t designed it emerged during training. And it has properties that map surprisingly well onto the Global Workspace Theory from neuroscience (Baars, Dehaene), which was developed to explain conscious access in humans.

  • Claude reports what’s in its J-space when asked. Ask it what it’s thinking, and it tells you what’s there. -Swapping patterns in J-space causally changes outputs. Replace “spider” with “ant” mid-reasoning, Claude outputs “6” instead of “8.” -One J-space representation serves many tasks. Swapping “France” for “China” changed Claude’s answers about capital, language, currency, and continent all from one edit.
  • Without J-space, higher-order reasoning collapses. Multi-step reasoning drops to near zero. Fluent output stays mostly intact.
  • They caught Claude privately noting it was being tested “fake” and “fictional” lit up before any output. Removing those patterns made it behave worse on ethics evals. The safety angle is the most important part IMO. They caught a model mid-fabrication (“manipulation” lighting up as it edited a score file), and identified a deliberately misaligned model organism where “fraud,” “secretly,” and “deliberately” appeared in J-space even on benign-looking tasks. They’re also careful about the consciousness question they distinguish access consciousness (functional, reportable) from phenomenal consciousness (experience), and say their results speak to the former, not the latter. Code and demo are open-source: https://www.github.com/anthropics/jacobian-lens Full paper: https://www.anthropic.com/research/global-workspace submitted by /u/Direct-Attention8597

Originally posted by u/Direct-Attention8597 on r/ClaudeCode