Where a concept lives · interactive

The quiet axis

Thirty prompts about consciousness and thirty matched philosophy prompts with the consciousness words scrubbed out, pushed through a 1.5B reasoning model. At every layer, the loudest directions in the activations mix the two groups together. A probe finds the direction that separates them. It is nearly silent, and it only appears late.

What PCA sees

the two loudest directions of variance at this layer

What a probe sees

probe axis, each point scored by a probe that never saw it, against the first PC
consciousnessmatched philosophy
layer 23of 28
0.97held-out AUC on the probe axis
0.82same at layer 0, the words alone

Model: loading. Mean-pooled activations, standardised per layer. Probe: logistic regression, leave-one-out, so no point is scored by a probe that trained on it. Coordinates are z-scored per layer. Hover a point to read the prompt.

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