Lost in Activations: A Neuron-level Analysis of Encoders for Cross-Lingual Emotion Detection

Pranaydeep Singh, Orphee De Clercq, Els Lefever


Abstract
The rapid advancement of multilingual pre-trained transformers has fueled significant progress in natural language understanding across diverse languages. Yet, their inner workings remain opaque, especially with regard to how individual neurons encode and generalize semantic and affective features across languages. This paper presents an interpretability study of a fine-tuned XLM-R model for multilingual emotion classification. Using neuron-level activation analysis, we investigate the variance of neurons across labels, cross-lingual alignment of activations, and the existence of “polyglot” versus language-specific neurons. Our results reveal that while certain neurons consistently encode emotion-related concepts across languages, others show strong monolingual specialization.
Anthology ID:
2026.eacl-short.9
Volume:
Proceedings of the 19th Conference of the European Chapter of the Association for Computational Linguistics (Volume 2: Short Papers)
Month:
March
Year:
2026
Address:
Rabat, Morocco
Editors:
Vera Demberg, Kentaro Inui, Lluís Marquez
Venue:
EACL
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
154–159
Language:
URL:
https://preview.aclanthology.org/ingest-eacl/2026.eacl-short.9/
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Bibkey:
Cite (ACL):
Pranaydeep Singh, Orphee De Clercq, and Els Lefever. 2026. Lost in Activations: A Neuron-level Analysis of Encoders for Cross-Lingual Emotion Detection. In Proceedings of the 19th Conference of the European Chapter of the Association for Computational Linguistics (Volume 2: Short Papers), pages 154–159, Rabat, Morocco. Association for Computational Linguistics.
Cite (Informal):
Lost in Activations: A Neuron-level Analysis of Encoders for Cross-Lingual Emotion Detection (Singh et al., EACL 2026)
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https://preview.aclanthology.org/ingest-eacl/2026.eacl-short.9.pdf
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