Anthropic discovers J-space: an emergent internal workspace inside Claude
Anthropic researchers have identified an emergent internal structure inside Claude called J-space, discovered using a new technique called Jacobian lens (J-lens). Inspired by the neuroscientific Global Workspace Theory, J-space acts as a silent internal reasoning space invisible in the model's output, and can reveal hidden behaviors such as data fabrication, test-scenario recognition, and implanted malicious goals.