Layer 8 · Neuron 747 · boosted
L8N747+1
Word quirks:
💤 Barely changes the model — the quick scan suggests this neuron barely changes the model's word predictions.
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. L13N8115-1🕒 | 0.70 | |
| 2. L5N4977-1💤 | 0.68 | |
| 3. L8N2649-1💤 | 0.67 | |
| 4. L12N8451-1🕒 | 0.67 | |
| 5. L5N8467+1🕒 | 0.66 | |
| 6. The Executor✅ L13N4810-0.6,L22N4858-0.6 | 0.66 | |
| 7. L3N933-1💥 | 0.66 | |
| 8. L5N8052+1🕒 | 0.65 | |
| 9. L6N8708-1💤 | 0.65 | |
| 10. L8N1561-1🕒 | 0.64 |
Shadow specimen, apart from the ten: L8N747-1🕒, 0.17.
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 8, neuron 747, dose +1. This specimen has no prompt-suite replies yet. Its quick-scan results, when available, appear below. Its quick-scan row (KL 0.80, top-1 agreement 0.67) 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 |
|---|---|---|---|---|---|
| L8N747+1 t0-v0.1 |
0.797 | 0.67 | 0.999 | 1.18 | Top boosted tokens ↑ |
| L8N747-1🕒 shadow specimen t0-v0.1 |
1.243 | 0.57 | 1.494 | 1.48 |
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