Artifacts and Attention Sinks: Structured Approximations for Efficient Vision Transformers

Fuente: arXiv
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Autores principales: Lu, Andrew, Liao, Wentinn, Wang, Liuhui, Yang, Huzheng, Shi, Jianbo
Formato: Preprint
Publicado: 2025
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author Lu, Andrew
Liao, Wentinn
Wang, Liuhui
Yang, Huzheng
Shi, Jianbo
author_facet Lu, Andrew
Liao, Wentinn
Wang, Liuhui
Yang, Huzheng
Shi, Jianbo
contents Vision transformers have emerged as a powerful tool across a wide range of applications, yet their inner workings remain only partially understood. In this work, we examine the phenomenon of massive tokens - tokens with exceptionally high activation norms that act as attention sinks - and artifact tokens that emerge as a byproduct during inference. Our analysis reveals that these tokens mutually suppress one another through the attention mechanism, playing a critical role in regulating information flow within the network. Leveraging these insights, we introduce Fast Nyström Attention (FNA), a training-free method that approximates self-attention in linear time and space by exploiting the structured patterns formed by massive and artifact tokens. Additionally, we propose a masking strategy to mitigate noise from these tokens, yielding modest performance gains at virtually no cost. We evaluate our approach on popular pretrained vision backbones and demonstrate competitive performance on retrieval, classification, segmentation, and visual question answering (VQA), all while reducing computational overhead.
format Preprint
id arxiv_https___arxiv_org_abs_2507_16018
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Artifacts and Attention Sinks: Structured Approximations for Efficient Vision Transformers
Lu, Andrew
Liao, Wentinn
Wang, Liuhui
Yang, Huzheng
Shi, Jianbo
Computer Vision and Pattern Recognition
Vision transformers have emerged as a powerful tool across a wide range of applications, yet their inner workings remain only partially understood. In this work, we examine the phenomenon of massive tokens - tokens with exceptionally high activation norms that act as attention sinks - and artifact tokens that emerge as a byproduct during inference. Our analysis reveals that these tokens mutually suppress one another through the attention mechanism, playing a critical role in regulating information flow within the network. Leveraging these insights, we introduce Fast Nyström Attention (FNA), a training-free method that approximates self-attention in linear time and space by exploiting the structured patterns formed by massive and artifact tokens. Additionally, we propose a masking strategy to mitigate noise from these tokens, yielding modest performance gains at virtually no cost. We evaluate our approach on popular pretrained vision backbones and demonstrate competitive performance on retrieval, classification, segmentation, and visual question answering (VQA), all while reducing computational overhead.
title Artifacts and Attention Sinks: Structured Approximations for Efficient Vision Transformers
topic Computer Vision and Pattern Recognition
url https://arxiv.org/abs/2507.16018