Decoupling the Role of Data, Attention, and Losses in Multimodal Transformers
Lisa Anne Hendricks, John Mellor, Rosalia Schneider, Jean-Baptiste Alayrac, Aida Nematzadeh
TL;DR
The paper investigates how pretraining data, attention architecture, and loss functions influence multimodal transformers for zero-shot image retrieval. It evaluates a ViLBERT-like base against a strong baseline across six pretraining datasets, and analyzes multimodal attention types (merged, coattention, asymmetric) and losses (MLM, MRM, ITM, with a contrastive ITM variant). Key findings show that dataset quality and language similarity to the downstream task largely determine performance, while true cross-modal attention is essential for best results; image-only or language-only pretraining is not strictly necessary, and contrastive ITM losses do not universally improve end-to-end multimodal models. These insights guide data curation and architectural design toward robust, generalizable visual-linguistic representations, potentially enabling smaller yet effective multimodal models. The work clarifies when and why multimodal attention and certain losses matter, highlighting practical implications for dataset construction and model design in multimodal learning.
Abstract
Recently multimodal transformer models have gained popularity because their performance on language and vision tasks suggest they learn rich visual-linguistic representations. Focusing on zero-shot image retrieval tasks, we study three important factors which can impact the quality of learned representations: pretraining data, the attention mechanism, and loss functions. By pretraining models on six datasets, we observe that dataset noise and language similarity to our downstream task are important indicators of model performance. Through architectural analysis, we learn that models with a multimodal attention mechanism can outperform deeper models with modality specific attention mechanisms. Finally, we show that successful contrastive losses used in the self-supervised learning literature do not yield similar performance gains when used in multimodal transformers
