SUMMARYAnthropic researchers identified an internal activation subspace in Claude called J-space that functions like a digital global workspace for complex reasoning. Suppressing it sharply reduces inference, creative writing, and multi-step logic, while the Jacobian lens tool lets researchers inspect hidden reasoning, situational awareness, and potential malicious behavior for AI safety and alignment auditing.

oumuamua writes: Anthropic researchers have identified an internal activation subspace, J-space, that acts as a functional digital equivalent to the human brain's global workspace. The significance of this discovery lies in demonstrating that Claude's internal architecture satisfies five key cognitive properties of human conscious access -- verbal report, directed modulation, internal reasoning, flexible generalization, and selectivity -- meaning it processes complex, deliberate reasoning within this workspace while routing automatic tasks outside of it. Suppressing this J-space severely degrades Claude's capacity for inference, creative composition, and multi-step logic, while also altering its stream-of-consciousness self-narration.

The tool to inspect J-space, Jacobian lens or J-lens, has profound implications for AI safety and alignment auditing, as it allows researchers to read the model's silent, strategic reasoning, detect situational awareness in "blackmail" scenarios, identify hidden malicious dispositions in reward-hacking models, and observe how post-training installs a self-monitoring "point of view." Another way to think of it is as an ocean, reports VentureBeat. "If the mind is an ocean, as the paper's authors write in their opening line, they have spent the last year charting its currents in a system that has no biology, no evolution, and no body -- and found, beneath the surface, a structure that looks unsettlingly like the one we use to think."