Knowing or Guessing? Robust Medical Visual Question Answering via Joint Consistency and Contrastive Learning

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Jiang, Songtao, Chen, Yuxi, Song, Sibo, Zhang, Yan, Jin, Yeying, Feng, Yang, Wu, Jian, Liu, Zuozhu
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866908503925325824
author Jiang, Songtao
Chen, Yuxi
Song, Sibo
Zhang, Yan
Jin, Yeying
Feng, Yang
Wu, Jian
Liu, Zuozhu
author_facet Jiang, Songtao
Chen, Yuxi
Song, Sibo
Zhang, Yan
Jin, Yeying
Feng, Yang
Wu, Jian
Liu, Zuozhu
contents In high-stakes medical applications, consistent answering across diverse question phrasings is essential for reliable diagnosis. However, we reveal that current Medical Vision-Language Models (Med-VLMs) exhibit concerning fragility in Medical Visual Question Answering, as their answers fluctuate significantly when faced with semantically equivalent rephrasings of medical questions. We attribute this to two limitations: (1) insufficient alignment of medical concepts, leading to divergent reasoning patterns, and (2) hidden biases in training data that prioritize syntactic shortcuts over semantic understanding. To address these challenges, we construct RoMed, a dataset built upon original VQA datasets containing 144k questions with variations spanning word-level, sentence-level, and semantic-level perturbations. When evaluating state-of-the-art (SOTA) models like LLaVA-Med on RoMed, we observe alarming performance drops (e.g., a 40\% decline in Recall) compared to original VQA benchmarks, exposing critical robustness gaps. To bridge this gap, we propose Consistency and Contrastive Learning (CCL), which integrates two key components: (1) knowledge-anchored consistency learning, aligning Med-VLMs with medical knowledge rather than shallow feature patterns, and (2) bias-aware contrastive learning, mitigating data-specific priors through discriminative representation refinement. CCL achieves SOTA performance on three popular VQA benchmarks and notably improves answer consistency by 50\% on the challenging RoMed test set, demonstrating significantly enhanced robustness. Code will be released.
format Preprint
id arxiv_https___arxiv_org_abs_2508_18687
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Knowing or Guessing? Robust Medical Visual Question Answering via Joint Consistency and Contrastive Learning
Jiang, Songtao
Chen, Yuxi
Song, Sibo
Zhang, Yan
Jin, Yeying
Feng, Yang
Wu, Jian
Liu, Zuozhu
Computation and Language
In high-stakes medical applications, consistent answering across diverse question phrasings is essential for reliable diagnosis. However, we reveal that current Medical Vision-Language Models (Med-VLMs) exhibit concerning fragility in Medical Visual Question Answering, as their answers fluctuate significantly when faced with semantically equivalent rephrasings of medical questions. We attribute this to two limitations: (1) insufficient alignment of medical concepts, leading to divergent reasoning patterns, and (2) hidden biases in training data that prioritize syntactic shortcuts over semantic understanding. To address these challenges, we construct RoMed, a dataset built upon original VQA datasets containing 144k questions with variations spanning word-level, sentence-level, and semantic-level perturbations. When evaluating state-of-the-art (SOTA) models like LLaVA-Med on RoMed, we observe alarming performance drops (e.g., a 40\% decline in Recall) compared to original VQA benchmarks, exposing critical robustness gaps. To bridge this gap, we propose Consistency and Contrastive Learning (CCL), which integrates two key components: (1) knowledge-anchored consistency learning, aligning Med-VLMs with medical knowledge rather than shallow feature patterns, and (2) bias-aware contrastive learning, mitigating data-specific priors through discriminative representation refinement. CCL achieves SOTA performance on three popular VQA benchmarks and notably improves answer consistency by 50\% on the challenging RoMed test set, demonstrating significantly enhanced robustness. Code will be released.
title Knowing or Guessing? Robust Medical Visual Question Answering via Joint Consistency and Contrastive Learning
topic Computation and Language
url https://arxiv.org/abs/2508.18687