Zero-Shot Cross-Lingual Recognition of Sign Language Handshapes

Marcel Granero-Moya*, Carolina del Corral Farrarós*, Gloria Haro, Coloma Ballester, Ricardo Marques
Universitat Pompeu Fabra
*Equal contribution
2nd Workshop on Sign Language Processing (WSLP @ EMNLP 2026)

Abstract

Sign language processing advances rapidly for high-resource languages such as American Sign Language (ASL), yet most of the world's sign languages lack the phonological annotations new methods require. We present the first zero-shot cross-lingual framework for handshape recognition, transferring from ASL to Catalan Sign Language (LSC). Our approach leverages the decomposition of handshapes into five phonological features — selected fingers, flexion, spread, thumb position, and thumb contact — shared across both languages, to decode LSC handshapes from predicted features via a composite phonological distance metric. We evaluate three architectures (MLP, SL-GCN, SHuBERT) trained on two ASL corpora (PopSign, Sem-Lex) against a 37-handshape, single-signer LSC benchmark. Zero-shot transfer proves viable once recording-format disparities are harmonized, reaching 80.0% phonological feature accuracy and 54.5% expected handshape accuracy. Phonological decomposition thus offers a bridge for extending sign language technologies to low-resource languages without any target-language video training labels.

BibTeX

Please cite the WSLP @ EMNLP 2026 workshop paper; the arXiv entry is the same work, recorded below as eprint.

@inproceedings{granero-moya-etal-2026-zero-shot,
  title     = {Zero-Shot Cross-Lingual Recognition of Sign Language Handshapes},
  author    = {Granero-Moya, Marcel and del Corral Farrar{\'o}s, Carolina
               and Haro, Gloria and Ballester, Coloma and Marques, Ricardo},
  booktitle = {Proceedings of the Second Workshop on Sign Language Processing (WSLP)},
  month     = oct,
  year      = {2026},
  address   = {Budapest, Hungary (Co-located with EMNLP 2026)},
  publisher = {Association for Computational Linguistics},
  eprint    = {2609.18772},
  archivePrefix = {arXiv},
  primaryClass  = {cs.CL}
}