Discovering Language-neutral Sub-networks in Multilingual Language Models

Negar Foroutan, Mohammadreza Banaei, Rémi Lebret, Antoine Bosselut, Karl Aberer


Abstract
Multilingual pre-trained language models transfer remarkably well on cross-lingual downstream tasks. However, the extent to which they learn language-neutral representations (i.e., shared representations that encode similar phenomena across languages), and the effect of such representations on cross-lingual transfer performance, remain open questions.In this work, we conceptualize language neutrality of multilingual models as a function of the overlap between language-encoding sub-networks of these models. We employ the lottery ticket hypothesis to discover sub-networks that are individually optimized for various languages and tasks. Our evaluation across three distinct tasks and eleven typologically-diverse languages demonstrates that sub-networks for different languages are topologically similar (i.e., language-neutral), making them effective initializations for cross-lingual transfer with limited performance degradation.
Anthology ID:
2022.emnlp-main.513
Volume:
Proceedings of the 2022 Conference on Empirical Methods in Natural Language Processing
Month:
December
Year:
2022
Address:
Abu Dhabi, United Arab Emirates
Editors:
Yoav Goldberg, Zornitsa Kozareva, Yue Zhang
Venue:
EMNLP
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
7560–7575
Language:
URL:
https://aclanthology.org/2022.emnlp-main.513
DOI:
10.18653/v1/2022.emnlp-main.513
Bibkey:
Cite (ACL):
Negar Foroutan, Mohammadreza Banaei, Rémi Lebret, Antoine Bosselut, and Karl Aberer. 2022. Discovering Language-neutral Sub-networks in Multilingual Language Models. In Proceedings of the 2022 Conference on Empirical Methods in Natural Language Processing, pages 7560–7575, Abu Dhabi, United Arab Emirates. Association for Computational Linguistics.
Cite (Informal):
Discovering Language-neutral Sub-networks in Multilingual Language Models (Foroutan et al., EMNLP 2022)
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PDF:
https://preview.aclanthology.org/nschneid-patch-2/2022.emnlp-main.513.pdf