Hypercomplex Transformer: Novel Attention Mechanism

Maxim Gordeev, Zuev Aleksandr, Mikhail Bakulin, Andrey Latyshev, Dmitry Kozlov, Yiwu Yao, Voronova Anastasia


Abstract
Self-attention mechanisms have become foundational across modern deep learning architectures. Recent efforts focus on improving their efficiency, particularly for signal processing tasks. The existing approaches employ complex-valued representations for inputs and weights and achieve higher accuracy at the cost of increased model size and inference latency. Dual-numbered algebra offers a promising alternative that allows efficient multiplication and faster inference with the same representational capacity. Inspired by previous studies in the field of hypercomplex neural networks, we introduce a generalized hypercomplex attention block and integrate it into Transformer-based models for EEG classification. Our experiments include adaptation of the hypercomplex models, so that the number of parameters is equal to that of their real-valued counterparts. Across all scenarios, the dual- and complex-numbered models consistently outperform the real ones, demonstrating superior accuracy. This work presents hypercomplex attention as a competitive and computationally efficient strategy with potential value to solve multiple NLP tasks.
Anthology ID:
2025.findings-ijcnlp.115
Volume:
Proceedings of the 14th International Joint Conference on Natural Language Processing and the 4th Conference of the Asia-Pacific Chapter of the Association for Computational Linguistics
Month:
December
Year:
2025
Address:
Mumbai, India
Editors:
Kentaro Inui, Sakriani Sakti, Haofen Wang, Derek F. Wong, Pushpak Bhattacharyya, Biplab Banerjee, Asif Ekbal, Tanmoy Chakraborty, Dhirendra Pratap Singh
Venue:
Findings
SIG:
Publisher:
The Asian Federation of Natural Language Processing and The Association for Computational Linguistics
Note:
Pages:
1845–1851
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URL:
https://preview.aclanthology.org/ingest-ijcnlp-aacl/2025.findings-ijcnlp.115/
DOI:
Bibkey:
Cite (ACL):
Maxim Gordeev, Zuev Aleksandr, Mikhail Bakulin, Andrey Latyshev, Dmitry Kozlov, Yiwu Yao, and Voronova Anastasia. 2025. Hypercomplex Transformer: Novel Attention Mechanism. In Proceedings of the 14th International Joint Conference on Natural Language Processing and the 4th Conference of the Asia-Pacific Chapter of the Association for Computational Linguistics, pages 1845–1851, Mumbai, India. The Asian Federation of Natural Language Processing and The Association for Computational Linguistics.
Cite (Informal):
Hypercomplex Transformer: Novel Attention Mechanism (Gordeev et al., Findings 2025)
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PDF:
https://preview.aclanthology.org/ingest-ijcnlp-aacl/2025.findings-ijcnlp.115.pdf