Discovering Knowledge-Critical Subnetworks in Pretrained Language Models

Fuente: arXiv
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Auteurs principaux: Bayazit, Deniz, Foroutan, Negar, Chen, Zeming, Weiss, Gail, Bosselut, Antoine
Format: Preprint
Publié: 2023
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author Bayazit, Deniz
Foroutan, Negar
Chen, Zeming
Weiss, Gail
Bosselut, Antoine
author_facet Bayazit, Deniz
Foroutan, Negar
Chen, Zeming
Weiss, Gail
Bosselut, Antoine
contents Pretrained language models (LMs) encode implicit representations of knowledge in their parameters. However, localizing these representations and disentangling them from each other remains an open problem. In this work, we investigate whether pretrained language models contain various knowledge-critical subnetworks: particular sparse computational subgraphs that can, if removed, precisely suppress specific knowledge the model has memorized. We propose a multi-objective differentiable masking scheme that can be applied to both weights and neurons to discover such subnetworks and show that we can use them to precisely remove specific knowledge from models while minimizing adverse effects on the behavior of the original model. We demonstrate our method on multiple GPT2 variants, uncovering highly sparse subnetworks (98%+ sparsity) that are critical for expressing specific collections of relational knowledge. When these subnetworks are removed, the remaining network maintains most of its initial abilities but struggles to represent the suppressed knowledge.
format Preprint
id arxiv_https___arxiv_org_abs_2310_03084
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Discovering Knowledge-Critical Subnetworks in Pretrained Language Models
Bayazit, Deniz
Foroutan, Negar
Chen, Zeming
Weiss, Gail
Bosselut, Antoine
Computation and Language
Artificial Intelligence
Machine Learning
Pretrained language models (LMs) encode implicit representations of knowledge in their parameters. However, localizing these representations and disentangling them from each other remains an open problem. In this work, we investigate whether pretrained language models contain various knowledge-critical subnetworks: particular sparse computational subgraphs that can, if removed, precisely suppress specific knowledge the model has memorized. We propose a multi-objective differentiable masking scheme that can be applied to both weights and neurons to discover such subnetworks and show that we can use them to precisely remove specific knowledge from models while minimizing adverse effects on the behavior of the original model. We demonstrate our method on multiple GPT2 variants, uncovering highly sparse subnetworks (98%+ sparsity) that are critical for expressing specific collections of relational knowledge. When these subnetworks are removed, the remaining network maintains most of its initial abilities but struggles to represent the suppressed knowledge.
title Discovering Knowledge-Critical Subnetworks in Pretrained Language Models
topic Computation and Language
Artificial Intelligence
Machine Learning
url https://arxiv.org/abs/2310.03084