ParamMute: Suppressing Knowledge-Critical FFNs for Faithful Retrieval-Augmented Generation

Fuente: arXiv
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Autores principales: Huang, Pengcheng, Liu, Zhenghao, Yan, Yukun, Zhao, Haiyan, Yi, Xiaoyuan, Chen, Hao, Liu, Zhiyuan, Sun, Maosong, Xiao, Tong, Yu, Ge, Xiong, Chenyan
Formato: Preprint
Publicado: 2025
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author Huang, Pengcheng
Liu, Zhenghao
Yan, Yukun
Zhao, Haiyan
Yi, Xiaoyuan
Chen, Hao
Liu, Zhiyuan
Sun, Maosong
Xiao, Tong
Yu, Ge
Xiong, Chenyan
author_facet Huang, Pengcheng
Liu, Zhenghao
Yan, Yukun
Zhao, Haiyan
Yi, Xiaoyuan
Chen, Hao
Liu, Zhiyuan
Sun, Maosong
Xiao, Tong
Yu, Ge
Xiong, Chenyan
contents Large language models (LLMs) integrated with retrieval-augmented generation (RAG) have improved factuality by grounding outputs in external evidence. However, they remain susceptible to unfaithful generation, where outputs contradict retrieved context despite its relevance and accuracy. Existing approaches aiming to improve faithfulness primarily focus on enhancing the utilization of external context, but often overlook the persistent influence of internal parametric knowledge during generation. In this work, we investigate the internal mechanisms behind unfaithful generation and identify a subset of mid-to-deep feed-forward networks (FFNs) that are disproportionately activated in such cases. Building on this insight, we propose Parametric Knowledge Muting through FFN Suppression (ParamMute), a framework that improves contextual faithfulness by suppressing the activation of unfaithfulness-associated FFNs and calibrating the model toward retrieved knowledge. To evaluate our approach, we introduce CoFaithfulQA, a benchmark specifically designed to evaluate faithfulness in scenarios where internal knowledge conflicts with accurate external evidence. Experimental results show that ParamMute significantly enhances faithfulness across both CoFaithfulQA and the established ConFiQA benchmark, achieving substantial reductions in reliance on parametric memory. These findings underscore the importance of mitigating internal knowledge dominance and provide a new direction for improving LLM trustworthiness in RAG. All codes are available at https://github.com/OpenBMB/ParamMute.
format Preprint
id arxiv_https___arxiv_org_abs_2502_15543
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle ParamMute: Suppressing Knowledge-Critical FFNs for Faithful Retrieval-Augmented Generation
Huang, Pengcheng
Liu, Zhenghao
Yan, Yukun
Zhao, Haiyan
Yi, Xiaoyuan
Chen, Hao
Liu, Zhiyuan
Sun, Maosong
Xiao, Tong
Yu, Ge
Xiong, Chenyan
Computation and Language
Artificial Intelligence
Large language models (LLMs) integrated with retrieval-augmented generation (RAG) have improved factuality by grounding outputs in external evidence. However, they remain susceptible to unfaithful generation, where outputs contradict retrieved context despite its relevance and accuracy. Existing approaches aiming to improve faithfulness primarily focus on enhancing the utilization of external context, but often overlook the persistent influence of internal parametric knowledge during generation. In this work, we investigate the internal mechanisms behind unfaithful generation and identify a subset of mid-to-deep feed-forward networks (FFNs) that are disproportionately activated in such cases. Building on this insight, we propose Parametric Knowledge Muting through FFN Suppression (ParamMute), a framework that improves contextual faithfulness by suppressing the activation of unfaithfulness-associated FFNs and calibrating the model toward retrieved knowledge. To evaluate our approach, we introduce CoFaithfulQA, a benchmark specifically designed to evaluate faithfulness in scenarios where internal knowledge conflicts with accurate external evidence. Experimental results show that ParamMute significantly enhances faithfulness across both CoFaithfulQA and the established ConFiQA benchmark, achieving substantial reductions in reliance on parametric memory. These findings underscore the importance of mitigating internal knowledge dominance and provide a new direction for improving LLM trustworthiness in RAG. All codes are available at https://github.com/OpenBMB/ParamMute.
title ParamMute: Suppressing Knowledge-Critical FFNs for Faithful Retrieval-Augmented Generation
topic Computation and Language
Artificial Intelligence
url https://arxiv.org/abs/2502.15543