STEERLSN: Training-Free Representation Alignment through Language-Specific Neuron Subspace Interpolation

Minjun Kim, Dongyeon Kim, Hoyun Song, Jihyo Kim, KyungTae Lim


Abstract
Recent advancements in Large Language Models (LLMs) have shown remarkable capabilities in multilingual contexts. However, previous studies suggest that multilingual LLMs primarily rely on the rich semantic knowledge of high-resource (i.e., English) representations to conduct tasks across languages. To mitigate the performance gap arising from resource imbalances, we propose Steering via Language-Specific Neurons, a training-free method that aligns non-English representations with the English manifold intervening on language-specific neuron activations via linear interpolation toward English activation prototypes. Experimental results show that the proposed method generally improves downstream task performance with minimal computational cost, yielding performance gains for low-resource scenarios where limited data often constrains knowledge coverage. Our findings suggest that the fundamental limitations of low-resource languages can be effectively alleviated by leveraging the robust representation space of high-resource languages, offering a promising direction for more balanced multilingual LLMs.
Anthology ID:
2026.findings-aacl.51
Volume:
Findings of the Association for Computational Linguistics: IJCNLP-AACL 2026
Month:
November
Year:
2026
Address:
Hengqin, China
Editors:
Yue Zhang, Ruifeng Xu, Ayu Purwarianti, Tong Rong, Jun Suzuki
Venue:
Findings
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
1005–1018
Language:
URL:
https://aclanthology.org/2026.findings-aacl.51/
DOI:
Bibkey:
Cite (ACL):
Minjun Kim, Dongyeon Kim, Hoyun Song, Jihyo Kim, and KyungTae Lim. 2026. STEERLSN: Training-Free Representation Alignment through Language-Specific Neuron Subspace Interpolation. In Findings of the Association for Computational Linguistics: IJCNLP-AACL 2026, pages 1005–1018, Hengqin, China. Association for Computational Linguistics.
Cite (Informal):
STEERLSN: Training-Free Representation Alignment through Language-Specific Neuron Subspace Interpolation (Kim et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-aacl.51.pdf