Bias Reduction in Visual Question Answering Using CLS-Based Contrastive Learning and ITM Loss
摘要
Visual Question Answering (VQA) requires models to understand both images and natural language questions to provide accurate answers. Existing VQA techniques are having language bias issue with predictions mostly depending on linguistic priors rather than visual grounding. By adding an extra Image-Text Matching (ITM) loss and CLS-based contrastive learning to the LXMERT architecture, this research work offers a novel way to reduce language bias. Our approach enhances visual grounding and induces alignment between image-question pairings by directly applying contrastive loss and using ITM signals to reinforce the model. The proposed model demonstrates improved bias reduction performance while maintaining competitive accuracy compared to existing VQA methods. Specifically, it achieves a bias rate of 24.28% on the VQAv2 dataset, outperforming recent baselines like CSS and RUBi during testing on a subset of the VQA v2 dataset of samples, demonstrating both quantitative improvement and qualitative resilience. This approach provides a scalable and interpretable framework that reduces biases in VQA, increasing the reliability and equity of vision-language systems.