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Surgical Activation Steering via Generative Causal Mediation

arXiv:2602.16080v1 Announce Type: new Abstract: Where should we intervene in a language model (LM) to control behaviors that are diffused across many tokens of a long-form response? We introduce Generative Causal Mediation (GCM), a procedure for selecting model components, e.g., attention heads, to steer a binary concept (e.g., talk in verse vs. talk in prose) from contrastive long-form responses. In GCM, we first construct a dataset of contrasting inputs and responses. Then, we quantify how individual model components mediate the contrastive concept and select the strongest mediators for steering. We evaluate GCM on three tasks--refusal, sycophancy, and style transfer--across three language models. GCM successfully localizes concepts expressed in long-form responses and consistently outperforms correlational probe-based baselines when steering with a sparse set of attention heads. Together, these results demonstrate that GCM provides an effective approach for localizing and controlli

arXiv:2602.16080v1 Announce Type: new Abstract: Where should we intervene in a language model (LM) to control behaviors that are diffused across many tokens of a long-form response? We introduce Generative Causal Mediation (GCM), a procedure for selecting model components, e.g., attention heads, to steer a binary concept (e.g., talk in verse vs. talk in prose) from contrastive long-form responses. In GCM, we first construct a dataset of contrasting inputs and responses. Then, we quantify how individual model components mediate the contrastive concept and select the strongest mediators for steering. We evaluate GCM on three tasks--refusal, sycophancy, and style transfer--across three language models. GCM successfully localizes concepts expressed in long-form responses and consistently outperforms correlational probe-based baselines when steering with a sparse set of attention heads. Together, these results demonstrate that GCM provides an effective approach for localizing and controlling the long-form responses of LMs.

Executive Summary

This article introduces Generative Causal Mediation (GCM), a novel approach for steering language models (LMs) to control behaviors diffused across multiple tokens in long-form responses. GCM constructs a dataset of contrasting inputs and responses, quantifies model component mediation, and selects the strongest mediators for steering. The approach is evaluated on three tasks across three language models, demonstrating its effectiveness in localizing concepts and controlling long-form responses. GCM outperforms correlational probe-based baselines when using a sparse set of attention heads. The results suggest that GCM provides a valuable tool for understanding and manipulating LM behavior, with potential applications in natural language processing, dialogue systems, and content generation.

Key Points

  • GCM is a novel approach for steering language models to control behaviors diffused across multiple tokens in long-form responses
  • GCM constructs a dataset of contrasting inputs and responses to quantify model component mediation
  • GCM selects the strongest mediators for steering and demonstrates effectiveness in localizing concepts and controlling long-form responses

Merits

Flexibility and Adaptability

GCM can be applied to various language models and tasks, allowing for flexibility and adaptability in steering LM behavior

Improves Understanding of LM Behavior

GCM provides a deeper understanding of how LMs mediate between inputs and responses, enabling more informed control of LM behavior

Demerits

Computational Complexity

GCM requires constructing a dataset of contrasting inputs and responses, which can be computationally expensive and time-consuming

Limited Generalizability

GCM's effectiveness may be limited to specific language models and tasks, requiring further evaluation and refinement

Expert Commentary

The introduction of GCM represents a significant advancement in the field of natural language processing, offering a novel approach to steering language models and controlling their behavior. The approach's flexibility and adaptability, as well as its ability to improve understanding of LM behavior, make it a valuable tool for researchers and practitioners alike. However, the computational complexity and limited generalizability of GCM require further refinement and evaluation. As GCM continues to evolve, it is essential to consider its implications for explainability and transparency in AI, as well as its potential impact on policy and regulation. Ultimately, GCM has the potential to revolutionize the field of NLP, enabling more sophisticated and nuanced control of language models and their applications.

Recommendations

  • Further evaluation and refinement of GCM to address computational complexity and limited generalizability
  • Investigation of GCM's applicability to other AI systems and tasks beyond language models

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