THOR: A Theta-Gamma Hierarchical Oscillatory Reasoning Framework for Multi-hop QA

Ziyang Ling, Ronald X. Xu, Mingzhai Sun


Abstract
Multi-hop question answering requires retrieving and integrating evidence from multiple contexts. Despite the rapid progress of current research, multi-hop reasoning remains constrained by two persistent limitations: attention decay, where the model’s focus on main question degrades as the reasoning chain grows, and error accumulation, where mistakes propagate across hops and compounds into final failure. Inspired by Theta-Gamma hierarchical oscillation which decouples global planning from local retrieval, enabling efficient attention transfer between hops and a verification and repair mechanism that interrupts the accumulation of errors in the wrong paths, we present **THOR**, a brain-inspired Theta-Gamma hierarchical oscillatory reasoning framework. Extensive comparative experiments and specific validation experiments on multi-hop QA benchmarks demonstrate that THOR improves answer accuracy and robustness while mitigating limitations, showcasing its generalization across different backbones.
Anthology ID:
2026.acl-long.935
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
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
20410–20437
Language:
URL:
https://aclanthology.org/2026.acl-long.935/
DOI:
10.18653/v1/2026.acl-long.935
Bibkey:
Cite (ACL):
Ziyang Ling, Ronald X. Xu, and Mingzhai Sun. 2026. THOR: A Theta-Gamma Hierarchical Oscillatory Reasoning Framework for Multi-hop QA. In Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), pages 20410–20437, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
THOR: A Theta-Gamma Hierarchical Oscillatory Reasoning Framework for Multi-hop QA (Ling et al., ACL 2026)
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PDF:
https://aclanthology.org/2026.acl-long.935.pdf
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