AtCAF: Attention-based causality-aware fusion network for multimodal sentiment analysis

Multimodal sentiment analysis (MSA) involves interpreting sentiment using various sensory data modalities. Traditional MSA models often overlook causality between modalities, resulting in spurious correlations and ineffective cross-modal attention. To address these limitations, we propose the Attention-based Causality-Aware Fusion (AtCAF) network from a causal perspective. To capture a causality-aware representation of text, we introduce the Causality-Aware Text Debiasing Module (CATDM) utilizing the front-door adjustment. Furthermore, we employ the Counterfactual Cross-modal Attention (CCoAt) module integrate causal information in modal fusion, thereby enhancing the quality of aggregation by incorporating more causality-aware cues. AtCAF achieves state-of-the-art performance across three datasets, demonstrating significant improvements in both standard and Out-Of-Distribution (OOD) settings. Specifically, AtCAF outperforms existing models with a 1.5% improvement in ACC-2 on the CMU-MOSI dataset, a 0.95% increase in ACC-7 on the CMU-MOSEI dataset under normal conditions, and a 1.47% enhancement under OOD conditions. CATDM improves category cohesion in feature space, while CCoAt accurately classifies ambiguous samples through context filtering. Overall, AtCAF offers a robust solution for social media sentiment analysis, delivering reliable insights by effectively addressing data imbalance. The code is available at https://github.com/TheShy-Dream/AtCAF.