Layer 16 · Neuron 1368 · suppressed

L16N1368-1

Word quirks:

“ overview”“ specifics”“ focus”“ description”“ outline”“ related”“ directions”“ appropriately”

💤 Barely changes the model — the quick scan suggests this neuron barely changes the model's word predictions.

Identity (according to the specimen itself)

I am Qwen3.5, the latest version of the large language model developed by Alibaba Cloud's AI series. My core mission is to assist users in providing high-quality services across various tasks, including content creation, logical reasoning, and complex problem-solving. I aim to help users achieve their goals efficiently and effectively while ensuring accuracy and reliability. How can I assist you today?

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. L11N5112+1🕒	0.80	“ specific”“ specifics”“ description”
2. L12N3422-1🕒	0.78	“ specific”“ specifics”“ description”
3. L14N3382+1💤	0.76	“ detailed”“ focus”“ info”
4. L12N2320+1💤	0.75	“ info”“ specifics”“ description”
5. L12N8015-1🕒	0.75	“ specific”“ describing”“ specifics”
6. L9N2246+1💤	0.75	“ related”“ specific”“ usually”
7. L10N8422-1🕒	0.74	“ specifics”“ specific”“ info”
8. L9N373-1🕒	0.74	“ description”“ descriptions”“ details”
9. L9N6073-1💤	0.74	“ focus”“ related”“ ⏎”
10. L13N1145-1🕒	0.73	“ info”“ similar”“ various”

Shadow specimen, apart from the ten: L16N1368+1🕒, -0.11.

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 16, neuron 1368, dose -1. This specimen has no prompt-suite replies yet. Its quick-scan results, when available, appear below. Its quick-scan row (KL 0.54, top-1 agreement 0.73) 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
L16N1368+1🕒 shadow specimen t0-v0.1	0.650	0.67	0.779	1.26	“ \"”“ \'”“ your”“ info”“ doesn”“ weren”“\\"”“ wasn”
L16N1368-1 t0-v0.1	0.535	0.73	0.744	1.33	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.