How multimodal models fuse vision and language reveals architectural trade-offs
Researchers dissect how multimodal language models fuse vision and text by comparing two architectural families: concatenation-based and native multimodal designs. Using alignment decoupling, attention routing analysis, and intrinsic dimensionality measurement, the work reveals which modalities drive fusion at each layer and how information flows across domains. Causal intervention validates findings. This mechanistic understanding matters because it exposes architectural trade-offs in how models integrate signals, informing both future MLLM design and interpretability efforts as these systems scale into production.62





