Evaluating and Steering Modality Preferences in Multimodal Large Language Model

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: Zhang, Yu, Ma, Jinlong, Hou, Yongshuai, Bai, Xuefeng, Chen, Kehai, Xiang, Yang, Yu, Jun, Zhang, Min
Formato: Preprint
Publicado: 2025
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866908810439819264
author Zhang, Yu
Ma, Jinlong
Hou, Yongshuai
Bai, Xuefeng
Chen, Kehai
Xiang, Yang
Yu, Jun
Zhang, Min
author_facet Zhang, Yu
Ma, Jinlong
Hou, Yongshuai
Bai, Xuefeng
Chen, Kehai
Xiang, Yang
Yu, Jun
Zhang, Min
contents Multi-modal large language models (MLLMs) have achieved remarkable success on complex multi-modal tasks. However, it remains insufficiently explored whether they exhibit $\textbf{modality preference}$, a tendency to favor one modality over another when processing multi-modal contexts. To study this question, we introduce $\textbf{MC\textsuperscript{2}}$ benchmark, which constructs controlled evidence-conflict scenarios to systematically evaluate modality preference in decision-making. Extensive experiments reveal that all 20 tested MLLMs generally demonstrate clear modality preferences, and such preferences can serve as a useful indicator of downstream task performance of MLLMs. Further analysis shows that modality preference can be controlled by instruction guidance and captured within the latent representations of MLLMs. Built on these insights, we propose a probing and steering method based on representation engineering to explicitly control modality preference without requiring additional fine-tuning. This method effectively amplifies modality preference toward a desired direction and demonstrates promising improvements across multiple multi-modal understanding and reasoning tasks.
format Preprint
id arxiv_https___arxiv_org_abs_2505_20977
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Evaluating and Steering Modality Preferences in Multimodal Large Language Model
Zhang, Yu
Ma, Jinlong
Hou, Yongshuai
Bai, Xuefeng
Chen, Kehai
Xiang, Yang
Yu, Jun
Zhang, Min
Computation and Language
Multi-modal large language models (MLLMs) have achieved remarkable success on complex multi-modal tasks. However, it remains insufficiently explored whether they exhibit $\textbf{modality preference}$, a tendency to favor one modality over another when processing multi-modal contexts. To study this question, we introduce $\textbf{MC\textsuperscript{2}}$ benchmark, which constructs controlled evidence-conflict scenarios to systematically evaluate modality preference in decision-making. Extensive experiments reveal that all 20 tested MLLMs generally demonstrate clear modality preferences, and such preferences can serve as a useful indicator of downstream task performance of MLLMs. Further analysis shows that modality preference can be controlled by instruction guidance and captured within the latent representations of MLLMs. Built on these insights, we propose a probing and steering method based on representation engineering to explicitly control modality preference without requiring additional fine-tuning. This method effectively amplifies modality preference toward a desired direction and demonstrates promising improvements across multiple multi-modal understanding and reasoning tasks.
title Evaluating and Steering Modality Preferences in Multimodal Large Language Model
topic Computation and Language
url https://arxiv.org/abs/2505.20977