@inproceedings{you-etal-2025-revealing,
    title = "Revealing and Mitigating the Local Pattern Shortcuts of Mamba",
    author = "You, WangJie  and
      Tang, Zecheng  and
      Li, Juntao  and
      Yao, Lili  and
      Zhang, Min",
    editor = "Che, Wanxiang  and
      Nabende, Joyce  and
      Shutova, Ekaterina  and
      Pilehvar, Mohammad Taher",
    booktitle = "Findings of the Association for Computational Linguistics: ACL 2025",
    month = jul,
    year = "2025",
    address = "Vienna, Austria",
    publisher = "Association for Computational Linguistics",
    url = "https://preview.aclanthology.org/landing_page/2025.findings-acl.629/",
    pages = "12156--12178",
    ISBN = "979-8-89176-256-5",
    abstract = "Large language models (LLMs) have advanced significantly due to the attention mechanism, but their quadratic complexity and linear memory demands limit their performance on long-context tasks. Recently, researchers introduced Mamba, an advanced model built upon State Space Models (SSMs) that offers linear complexity and constant memory. Although Mamba is reported to match or surpass the performance of attention-based models, our analysis reveals a performance gap: Mamba excels in tasks that involve localized key information but faces challenges with tasks that require handling distributed key information. Our controlled experiments suggest that the inconsistency arises from Mamba{'}s reliance on **local pattern shortcuts** across model scales (10M to 1.4B), which enable Mamba to remember local key information within its limited memory but hinder its ability to retain more dispersed information. Therefore, we introduce a global gate module into the Mamba model to address this issue. Experiments on extensive synthetic tasks, as well as real-world tasks, demonstrate the effectiveness of our method. Notably, with the introduction of only 4M extra parameters, our approach enables the Mamba model (130M) to achieve a significant improvement on tasks with distributed information, increasing its performance from **below 5{\%} to 80{\%}**."
}