Do Images Speak Louder than Words? Investigating the Effect of Textual Misinformation in VLMs

Chi Zhang, Wenxuan Ding, Jiale Liu, Mingrui Wu, Qingyun Wu, Ray Mooney


Abstract
Vision-Language Models (VLMs) have shown strong multimodal reasoning capability on Visual-Question-Answering (VQA) benchmarks. However, their robustness against textual misinformation remains under-explored. While existing research has extensively studied the effect of misinformation in text-only domains, it is not clear how VLMs arbitrate between contradictory information from different modalities. To bridge the gap, we first propose the ConText-VQA (i.e. Conflicting Text) dataset, consisting of image-question pairs together with systematically generated persuasive prompts that deliberately conflict with visual evidence. Then, a thorough testing framework is designed and executed to benchmark the susceptibility of various models to these conflicting textual inputs. Comprehensive experiments over 11 state-of-the-art VLMs reveal that these models are indeed vulnerable to misleading prompts, often overriding clear visual evidence in favor of the conflicting text, and show an average performance drop of over 48.2% after only one round of persuasive conversation. Our findings highlight a critical limitation in current VLMs and underscore the need for improved robustness against textual manipulation.
Anthology ID:
2026.eacl-long.323
Volume:
Proceedings of the 19th Conference of the European Chapter of the Association for Computational Linguistics (Volume 1: Long 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:
6872–6895
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URL:
https://preview.aclanthology.org/ingest-eacl/2026.eacl-long.323/
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Bibkey:
Cite (ACL):
Chi Zhang, Wenxuan Ding, Jiale Liu, Mingrui Wu, Qingyun Wu, and Ray Mooney. 2026. Do Images Speak Louder than Words? Investigating the Effect of Textual Misinformation in VLMs. In Proceedings of the 19th Conference of the European Chapter of the Association for Computational Linguistics (Volume 1: Long Papers), pages 6872–6895, Rabat, Morocco. Association for Computational Linguistics.
Cite (Informal):
Do Images Speak Louder than Words? Investigating the Effect of Textual Misinformation in VLMs (Zhang et al., EACL 2026)
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https://preview.aclanthology.org/ingest-eacl/2026.eacl-long.323.pdf