A Thousand Words or An Image: Studying the Influence of Persona Modality in Multimodal LLMs

Julius Broomfield, Kartik Sharma, Srijan Kumar


Abstract
Language models have demonstrated remarkable advancements in embodying diverse personas, enhancing their effectiveness as conversational agents. Simultaneously, there have been significant strides in these models in processing and integrating visual information. However, despite images being a natural carrier of persona attributes (e.g. age, occupation, or location), it remains largely unexplored whether multimodal language models (MLLMs) can faithfully ground visual persona information. In this work, we introduce persona embodiment as a novel diagnostic for visual grounding in MLLMs. Unlike simple visual recognition, this task requires models to extract multiple persona attributes from an image, integrate them into a coherent representation, and apply them to downstream language tasks. To this end, we introduce a modality-parallel dataset of personas, containing 2,400 prompts each represented in four modalities. Across our experiments, we find that models frequently underuse visual information relative to text, and that this neglect persists even when richer visual information is clearly available, highlighting underlying limitations and paving the way for future research to bridge this gap.
Anthology ID:
2026.findings-emnlp.1564
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
33309–33328
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.1564/
DOI:
10.18653/2026.findings-emnlp.1564
Bibkey:
Cite (ACL):
Julius Broomfield, Kartik Sharma, and Srijan Kumar. 2026. A Thousand Words or An Image: Studying the Influence of Persona Modality in Multimodal LLMs. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 33309–33328, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
A Thousand Words or An Image: Studying the Influence of Persona Modality in Multimodal LLMs (Broomfield et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.1564.pdf