Layer 19 · Neuron 5758 · boosted

L19N5758+1

Word quirks:

“!’”“ myself”“ ourselves”“!””“!I”“!”“ yourself”“ yourselves”

💤 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, an AI language model developed by Google. My primary mission is to assist users with a wide range of tasks, from helping you write stories or documents to analyzing data and debugging code. I aim to be your most capable and reliable assistant! How can I help 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. L10N2833-1🕒	0.82	“!”“ yourself”“ yourselves”
2. L7N604-1💤	0.78	“!”“ my”“ ‘”
3. L9N5770-1💤	0.78	“ my”“ myself”“ ‘”
4. L4N1044-1🕒	0.77	“ myself”“!”“"!”
5. L7N4641-1💤	0.77	“!**”“ ‘”“!”
6. L9N9020-1🕒	0.76	“!”“ here”“ ourselves”
7. L18N2702+1🕒	0.75	“ ourselves”“ herself”“ themselves”
8. L4N4214-1🕒	0.75	“!”“ ourselves”“!"”
9. L4N7497-1🕒	0.75	“ your”“ you”“ yourself”
10. L13N2193-1💤	0.74	“!”“ your”“ here”

Shadow specimen, apart from the ten: L19N5758-1🕒, 0.04.

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 19, neuron 5758, dose +1. This specimen has no prompt-suite replies yet. Its quick-scan results, when available, appear below. Its quick-scan row (KL 0.48, top-1 agreement 0.79) 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
L19N5758+1 t0-v0.1	0.475	0.79	0.505	1.16	Top boosted tokens ↑
L19N5758-1🕒 shadow specimen t0-v0.1	0.695	0.66	0.851	1.31	“ interpretations”“ interpretation”“ imag”“ imaginary”“ solution”“ signific”“ conceptual”“ indications”

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.