Layer 25 · Neuron 2050 · suppressed
L25N2050-1
Word quirks:
🧪 In testing — Answered 0 of 8 prompts so far.
Identity (according to the specimen itself)
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. L27N5231-1⛔ | 0.99 | |
| 2. L24N2234-1🕒 | 0.99 | |
| 3. L18N4305+1🕒 | 0.98 | |
| 4. L24N6346+1💤 | 0.98 | |
| 5. L28N4593+1💤 | 0.97 | |
| 6. L23N2167+1🕒 | 0.97 | |
| 7. L20N2754-1🕒 | 0.97 | |
| 8. L21N3634-1🕒 | 0.97 | |
| 9. L0N5119-1💥 | 0.95 | |
| 10. L27N6342-1🕒 | 0.95 |
Shadow specimen, apart from the ten: L25N2050+1🕒, 0.03.
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 25, neuron 2050, dose -1. This specimen has no prompt-suite replies yet. Its quick-scan results, when available, appear below. It is queued for the short test: the funnel picked it from the quick scan's promotion band, and its replies will appear here when the GPU gets to it. 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 |
|---|---|---|---|---|---|
| L25N2050+1🕒 shadow specimen t0-v0.1 |
0.653 | 0.68 | 0.693 | 1.46 | |
| L25N2050-1 t0-v0.1 |
1.305 | 0.64 | 1.295 | 1.04 | 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.
Poor Things