On the Language Encoder of Contrastive Cross-modal Models

Mengjie Zhao, Junya Ono, Zhi Zhong, Chieh-Hsin Lai, Yuhta Takida, Naoki Murata, Wei-Hsiang Liao, Takashi Shibuya, Hiromi Wakaki, Yuki Mitsufuji


Abstract
Contrastive cross-modal models such as CLIP and CLAP aid various vision-language (VL) and audio-language (AL) tasks. However, there has been limited investigation of and improvement in their language encoder – the central component of encoding natural language descriptions of image/audio into vector representations. We extensively evaluate how unsupervised and supervised sentence embedding training affect language encoder quality and cross-modal task performance. In VL pretraining, we found that sentence embedding training enhances language encoder quality and aids in cross-modal tasks, improving contrastive VL models such as CyCLIP. Sentence embedding training benefits AL tasks when the amount of training data is large. We analyze the representation spaces to understand the strengths of sentence embedding training, and find that it improves text-space uniformity, at the cost of decreased cross-modal alignment.
Anthology ID:
2024.findings-acl.293
Volume:
Findings of the Association for Computational Linguistics: ACL 2024
Month:
August
Year:
2024
Address:
Bangkok, Thailand
Editors:
Lun-Wei Ku, Andre Martins, Vivek Srikumar
Venue:
Findings
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
4923–4940
Language:
URL:
https://aclanthology.org/2024.findings-acl.293
DOI:
10.18653/v1/2024.findings-acl.293
Bibkey:
Cite (ACL):
Mengjie Zhao, Junya Ono, Zhi Zhong, Chieh-Hsin Lai, Yuhta Takida, Naoki Murata, Wei-Hsiang Liao, Takashi Shibuya, Hiromi Wakaki, and Yuki Mitsufuji. 2024. On the Language Encoder of Contrastive Cross-modal Models. In Findings of the Association for Computational Linguistics: ACL 2024, pages 4923–4940, Bangkok, Thailand. Association for Computational Linguistics.
Cite (Informal):
On the Language Encoder of Contrastive Cross-modal Models (Zhao et al., Findings 2024)
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PDF:
https://aclanthology.org/2024.findings-acl.293.pdf