Poor Things
Specimen ledger / L2N5313-1

Layer 2 · Neuron 5313 · suppressed

L2N5313-1

Word quirks:

“ statistical”“ analysis”“ statistic”“ Statistical”“ statist”“<|im_end|>”“ statistics”“ analyses”

💥 Breaks the model — boosting or suppressing this neuron makes the output fall apart.

Identity (according to the specimen itself)

The reply didn't hold together

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Nearest neighbors

Specimens with similar replies or word quirks. Similarity runs from −1 to 1; 1 is identical. These are leads, not shared mechanisms. How profiles are built.

By word quirks Profile recipe

SpecimenSimilarityWord quirks
1. L7N1233+1🕒0.99“ statistical”“ analyses”“ analysis”
2. L5N4092+1💥0.98“ statistical”“ statistic”“ Statistical”
3. L3N8469-1🕒0.98“ statistic”“ statistical”“ statist”
4. L8N872+1🕒0.97“ statistical”“ analyses”“ analysis”
5. L4N4255-1🕒0.97“ analysis”“ analyses”“ statistical”
6. The Meta-Analyst✅ L8N1512-10.97“ statistical”“ statistic”“ statistics”
7. L7N721-1🕒0.97“ statistically”“ statistical”“ stats”
8. L8N2639-1💤0.97“ statistical”“ statistically”“ stats”
9. L7N440+1🕒0.96“ statistical”“ statistically”“ statistics”
10. L4N4549-1🕒0.96“ statistical”“ analysis”“ theory”

Shadow specimen, apart from the ten: L2N5313+1💥, -0.08.

Cousins · specimens sharing a neuron

No specimen with replies shares this neuron yet.

Technical details

Quick scan: measure prediction shifts on fixed reference text. Short test: generate replies to a small set of prompts. Longer test: extend to a larger set. Full test: run the full prompt suite. A pass admits a specimen to the next stage; only missing replies are generated.

Layer 2, neuron 5313, dose -1. This specimen has no prompt-suite replies yet. Its quick-scan results, when available, appear below. Its quick-scan row (KL 3.18, top-1 agreement 0.31) is outside the band that feeds the short test (KL 1 to 2.5, agreement 0.5 to 0.65), so it stays at the quick scan unless someone queues it by hand. A hand pick goes straight to the full test. See Method for the tiers.

Quick scan · prediction measurements

Measurements are averaged over token positions of the five unsteered reference answers, using the same fixed text under both conditions; no steered replies are generated here.

  • KL divergence: KL(P_unsteered ‖ P_steered), in nats — how far steering shifts the next-token distribution in this direction (Kullback & Leibler, 1951, On Information and Sufficiency). Unsteered ≈ 0.001.
  • Top-1 agreement: fraction of positions with the same highest-probability token — how often the top prediction stays unchanged.
  • ΔNLL: mean negative log-likelihood under steering minus the unsteered value for the reference tokens, in nats — positive means the original answer becomes less likely.
  • Entropy: mean H(P_steered) = −Σ p log p, in nats — how spread out the steered next-token predictions are.

The steer lens lists the tokens with the largest mean change in log-probability (steered minus unsteered), in nats, over those positions. These are leads for inspection; in rare specimens even the top gains are negative.

SettingKL divergenceTop-1 agreementΔNLLEntropySteer lens
L2N5313+1💥 shadow specimen
t0-v0.1
2.6650.373.1692.64 “<|im_end|>”“⏎”“⏎ ⏎”“ ???”“...””“...</”“⏎ ⏎”“⏎⏎”
L2N5313-1
t0-v0.1
3.1830.313.6792.94 Top boosted tokens ↑

Method

A specimen is a fixed steering configuration of Qwen3.5-4B: one MLP neuron or a pair, each with a signed dose. Unsteered is the control. L identifies the layer; N, the neuron.

Additive activation steering. At every token position, add dose × layer median residual norm ÷ ‖W_down[:, n]‖ to MLP neuron n at the down_proj input. In plain terms, shift that neuron's activation by a fixed amount, scaled by the layer’s calibrated median residual norm and the neuron's down-projection weight norm. Positive doses push up; negative doses push down. Dose is normalized intervention size, not a percentage or probability.