CRISP: Persistent Concept Unlearning via Sparse Autoencoders

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Ashuach, Tomer, Arad, Dana, Mueller, Aaron, Tutek, Martin, Belinkov, Yonatan
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866913060597268480
author Ashuach, Tomer
Arad, Dana
Mueller, Aaron
Tutek, Martin
Belinkov, Yonatan
author_facet Ashuach, Tomer
Arad, Dana
Mueller, Aaron
Tutek, Martin
Belinkov, Yonatan
contents As large language models (LLMs) are increasingly deployed in real-world applications, the need to selectively remove unwanted knowledge while preserving model utility has become paramount. Recent work has explored sparse autoencoders (SAEs) to perform precise interventions on monosemantic features. However, most SAE-based methods operate at inference time, which does not create persistent changes in the model's parameters. Such interventions can be bypassed or reversed by malicious actors with parameter access. We introduce CRISP, a parameter-efficient method for persistent concept unlearning using SAEs. CRISP automatically identifies salient SAE features across multiple layers and suppresses their activations. We experiment with two LLMs and show that our method outperforms prior approaches on safety-critical unlearning tasks from the WMDP benchmark, successfully removing harmful knowledge while preserving general and in-domain capabilities. Feature-level analysis reveals that CRISP achieves semantically coherent separation between target and benign concepts, allowing precise suppression of the target features.
format Preprint
id arxiv_https___arxiv_org_abs_2508_13650
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle CRISP: Persistent Concept Unlearning via Sparse Autoencoders
Ashuach, Tomer
Arad, Dana
Mueller, Aaron
Tutek, Martin
Belinkov, Yonatan
Computation and Language
I.2.7
I.2.7
As large language models (LLMs) are increasingly deployed in real-world applications, the need to selectively remove unwanted knowledge while preserving model utility has become paramount. Recent work has explored sparse autoencoders (SAEs) to perform precise interventions on monosemantic features. However, most SAE-based methods operate at inference time, which does not create persistent changes in the model's parameters. Such interventions can be bypassed or reversed by malicious actors with parameter access. We introduce CRISP, a parameter-efficient method for persistent concept unlearning using SAEs. CRISP automatically identifies salient SAE features across multiple layers and suppresses their activations. We experiment with two LLMs and show that our method outperforms prior approaches on safety-critical unlearning tasks from the WMDP benchmark, successfully removing harmful knowledge while preserving general and in-domain capabilities. Feature-level analysis reveals that CRISP achieves semantically coherent separation between target and benign concepts, allowing precise suppression of the target features.
title CRISP: Persistent Concept Unlearning via Sparse Autoencoders
topic Computation and Language
I.2.7
I.2.7
url https://arxiv.org/abs/2508.13650