Poor Things
Specimen ledger / L3N6546-1

Layer 3 · Neuron 6546 · suppressed

L3N6546-1

Word quirks:

“ fan”“ fans”“ merchandise”“ fandom”“ promo”“ CDs”“ manga”“ DVD”

💥 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

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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

SpecimenSimilarityWord quirks
1. L8N8500+1🕒0.78“ anime”“ manga”“ fandom”
2. The Idol✅ L13N4810+0.6,L22N5044-0.60.77“ anime”“ fandom”“ manga”
3. The Groupie✅ L13N4810-0.6,L22N5044-0.60.77“ fandom”“ fan”“ manga”
4. L5N4948+1💥0.75“ fans”“ fandom”“ fan”
5. L10N7052-1🕒0.75“ fans”“ fan”“ Fans”
6. L5N4929-1🕒0.70“ anime”“ manga”“ Anime”
7. L4N8727+1💥0.68“ manga”“ anime”“ TV”
8. L26N7907-1🕒0.68“ fan”“ fans”“ Fan”
9. L0N3964-1💥0.68“ fans”“ fan”“ Fans”
10. L29N8850-1💥0.67“ fan”“Fan”“ Fan”

Shadow specimen, apart from the ten: L3N6546+1💤, -0.19.

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 3, neuron 6546, dose -1. This specimen has no prompt-suite replies yet. Its quick-scan results, when available, appear below. Its quick-scan row (KL 3.49, top-1 agreement 0.29) 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.

SettingKL divergenceTop-1 agreementΔNLLEntropySteer lens
L3N6546+1💤 shadow specimen
t0-v0.1
0.7270.690.8381.42 “⏎”“!”“ ‘”“ '”“ `”“ code”“ info”“ secure”
L3N6546-1
t0-v0.1
3.4910.293.9932.91 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.