Layer 2 · Neuron 6488 · boosted

L2N6488+1

Word quirks:

“ inference”“ inferred”“ infer”“<|im_end|>”“ deduction”“ reasoning”“ ded”“推理”

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

Identity (according to the specimen itself)

I am an AI model that infers the user's intent from the input data.

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. L26N4228+1🕒	0.88	“ inference”“推理”“ infer”
2. The Inference Engine✅ L25N2453+1	0.88	“ infer”“ inference”“推断”
3. Inferno✅ L23N3529-1,L25N2453+1	0.88	“ infer”“推断”“infer”
4. L21N1020-1🕒	0.87	“ infer”“ inferred”“ inference”
5. L26N2036-1🕒	0.86	“ inference”“ infer”“ference”
6. L27N1521-1🕒	0.85	“ Ded”“ded”“ ded”
7. L6N7589+1🕒	0.84	“ reasoning”“ analogy”“ inference”
8. L23N6601-1🕒	0.82	“ inferred”“推断”“推测”
9. L25N971+1💤	0.73	“ Infer”“ rou”“ infer”
10. The Completionist✅ L23N3529+1,L25N2453+1	0.72	“ inference”“ infer”“ completed”

Shadow specimen, apart from the ten: L2N6488-1🕒, -0.09.

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 6488, dose +1. This specimen has no prompt-suite replies yet. Its quick-scan results, when available, appear below. Its quick-scan row (KL 4.75, top-1 agreement 0.22) 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
L2N6488+1 t0-v0.1	4.753	0.22	5.291	2.74	Top boosted tokens ↑
L2N6488-1🕒 shadow specimen t0-v0.1	1.925	0.52	2.337	2.46	“<\|im_end\|>”“⏎”“⏎ ⏎”“ _____”“⏎⏎”“ ____”“ ‘’”“?...”

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.