Multi-Directional Ablation of Refusal in LLMs

Published:

Extension of Refusal in Language Models Is Mediated by a Single Direction (Arditi et al., 2024). The original paper claims a single direction in activation space is sufficient to elicit / suppress refusal; this project tests whether multiple directions improve the ablation.

Key findings:

  • Two-direction ablation improves refusal suppression over the one-direction baseline.
  • The optimal pair is not the top-2 ranked candidate directions from the original method — interaction effects between directions matter.
  • CE loss shows only a minor, linear increase as more directions are ablated, suggesting the additional directions are not load-bearing for general capabilities.

Built on top of andyrdt/refusal_direction. The original pipeline (direction extraction → selection → completion eval → CE loss) is extended to multi-vector ablation, with combinations evaluated by jailbreak score on a held-out harmful-prompt set.

GitHub · Reference paper (arXiv)

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