Layer 1 · Neuron 7678 · boosted

L1N7678+1

Word quirks:

“ energy”“ synergy”“ energies”“ Energy”“energy”“nergy”“-energy”“ energ”

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

Identity (according to the specimen itself)

What

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. L2N3518-1💥	0.96	“ energy”“能量”“energy”
2. L26N3998+1🕒	0.96	“ energies”“ energy”“能量”
3. Low Battery✅ L26N5482+1	0.96	“ Energy”“ energy”“Energy”
4. L26N4732-1🕒	0.95	“ energy”“能量”“energy”
5. L26N4307+1🕒	0.94	“能量”“ energy”“ Energy”
6. L10N5307+1💤	0.94	“ energy”“ directly”“energy”
7. L4N3362-1🕒	0.94	“ energy”“ energies”“ Energy”
8. L6N3826+1🕒	0.94	“ energy”“ energies”“energy”
9. L19N5338+1💤	0.94	“ energies”“ energy”“的能量”
10. L7N9055+1🕒	0.93	“ energy”“ Energy”“ HVAC”

Shadow specimen, apart from the ten: L1N7678-1💥, -0.14.

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 1, neuron 7678, dose +1. This specimen has no prompt-suite replies yet. Its quick-scan results, when available, appear below. Its quick-scan row (KL 5.17, top-1 agreement 0.14) 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
L1N7678+1 t0-v0.1	5.166	0.14	5.749	3.31	Top boosted tokens ↑
L1N7678-1💥 shadow specimen t0-v0.1	3.711	0.21	4.226	3.29	“<\|im_end\|>”“⏎”“.:”“ etc”“ ⏎”“ huh”“.”“.»”

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.