Temporal Precision Matters: Brain-Tuning Speech Language Models with Millisecond-Resolution Neural Signals

Zhejun Zhang, Wenqing Zhou, Haozhe Xu, Lin Zhang, Lei Li


Abstract
Brain-tuning enhances brain alignment and downstream performance by fine-tuning speech language models with neural recordings. However, previous work relies primarily on fMRI, whose temporal resolution integrates neural activity over seconds, blending distinct processing stages into a single supervision signal and precluding temporally targeted training. We introduce ECoG-tuning, which leverages electrocorticography’s millisecond precision to train speech language models. We design temporally targeted windows—a speech window capturing acoustic-phonetic encoding and a language window capturing higher-order linguistic processing—grounded in neuroscientific findings about temporal encoding hierarchies. Evaluating three models on the Podcast ECoG dataset, we find that ECoG-tuning significantly improves brain alignment over pretrained and distillation baselines. Notably, full spatiotemporal dynamics yield 7–17% higher alignment than time-averaged supervision across models, and language-window tuning produces larger gains in higher-order language regions, indicating that temporal precision provides additional training value. Moreover, ECoG-tuned models consistently improve or maintain downstream performance. Overall, our work provides initial evidence that electrophysiology is a viable brain-tuning modality, demonstrating how neuroscientific insights into processing hierarchies can inform principled model training strategies. Code is available at [https://github.com/Mochizuki-BUPT/ECoG-Tuning-main](https://github.com/Mochizuki-BUPT/ECoG-Tuning-main).
Anthology ID:
2026.acl-long.1911
Volume:
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Month:
July
Year:
2026
Address:
San Diego, California, United States
Editors:
Maria Liakata, Viviane P. Moreira, Jiajun Zhang, David Jurgens
Venue:
ACL
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Publisher:
Association for Computational Linguistics
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Pages:
41208–41226
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URL:
https://preview.aclanthology.org/ingest-acl/2026.acl-long.1911/
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Cite (ACL):
Zhejun Zhang, Wenqing Zhou, Haozhe Xu, Lin Zhang, and Lei Li. 2026. Temporal Precision Matters: Brain-Tuning Speech Language Models with Millisecond-Resolution Neural Signals. In Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), pages 41208–41226, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
Temporal Precision Matters: Brain-Tuning Speech Language Models with Millisecond-Resolution Neural Signals (Zhang et al., ACL 2026)
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https://preview.aclanthology.org/ingest-acl/2026.acl-long.1911.pdf
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