PASTA: Steering LLM Attention Toward Highlighted Prompt Text

Tell Your Model Where to Attend: Post-hoc Attention Steering for LLMs — Zhang, Singh, Liu, Liu, Yu, Gao, Zhao · arXiv Nov 2023 · ICLR 2024
arXiv 2311.02262 No weights changed α = 0.01 → ×100

Rescale outside the span, renormalize

One attention row in one steered head. Click tokens to define the highlighted span. Illustrative weights The operation itself follows the paper.
outside span: score × α → renormalize to sum 1  ⇒  span relatively ×(1/α). Paper fixes α = 0.01.

Why multiply, not add?

Shares inside the span only. Illustrative Adding a large constant flattens differences; scaling the outside keeps them.

Four ways to control a model

Click a box. PASTA is none of the other three.

Where a head gets edited

ITI is the closest relative: it also picks a sparse set of heads.

Profile once per model

Steering all heads performs worse than zero-shot; single heads or layers swing wildly.

LLaMA-7B: 32 layers × 32 heads = 1024

Per-head scores are a synthetic pattern Illustrative — not the paper's measurements. Slide k to see a top-k cut.
Hover a cell

Reported: head-set sizes and selection strategy

Task sets end up at 53, 86, 86, 86 heads (task order not given in episode). Strategy scores are averages.

Reported results (LLaMA-7B unless noted)

All values are percentages, higher is better. "~" marks approximate figures from the episode.

Alpha: forgiving, except zero

Stable from roughly 0.05 down to 1e-4.

Fluency guard (bigram + trigram entropy)

Outputs below 3.0 are discarded. Appendix D failure: repeated "They are a photographer."

How held-out is "task-agnostic"?

Tested vs not shown

Per the hosts' discussion of the paper.

References