Layer 31 · Neuron 8412 · suppressed

L31N8412-1

Word quirks:

“رف”“势”“voi”“ois”“وتي”“phu”“AGER”“ону”

💥 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

Harrideinginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginginging

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

Specimen	Similarity	Word quirks
1. L28N2566+1💤	0.65	“ongi”“وف”“OSS”
2. L22N2200+1💤	0.65	“ conos”“ouser”“金斯”
3. L31N1618+1💥	0.65	“卢”“Sel”“uves”
4. L25N8724-1🕒	0.65	“rais”“唯”“Wis”
5. L31N6526+1💥	0.64	“olah”“rame”“وش”
6. L26N861+1💤	0.64	“ Polski”“ozo”“бри”
7. L31N8580-1💥	0.63	“�”“傅”“eringen”
8. L27N5951+1💤	0.63	“芮”“oulouse”“chner”
9. L31N6318+1💥	0.63	“uhn”“ovice”“avic”
10. L26N6579-1💤	0.63	“iges”“依”“轮”

Shadow specimen, apart from the ten: L31N8412+1💥, 0.39.

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 31, neuron 8412, dose -1. This specimen has no prompt-suite replies yet. Its quick-scan results, when available, appear below. Its quick-scan row (KL 5.76, top-1 agreement 0.12) 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.

Setting	KL divergence	Top-1 agreement	ΔNLL	Entropy	Steer lens
L31N8412+1💥 shadow specimen t0-v0.1	5.365	0.18	5.728	9.78	“oks”“hir”“initely”“eman”“-solid”“Solid”“àm”“okus”
L31N8412-1 t0-v0.1	5.757	0.12	5.975	9.90	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.