Do More Modalities Always Help? A Geometric Perspective on Missing-Modality Robustness

Excerpt

arXiv:2610.04792v1 Announce Type: new Abstract: Missing modality remains a longstanding challenge in multimodal learning. Existing methods typically address this issue through modality recovery or adaptive strategies. However, they overlook models' internal cross-modal dependencies formed during multimodal training, which later impair robustness. We systematically characterize a counterintuitive deployment-time failure mode: models trained on full modalities can underperform unimodal models when