Sentiment-Intensity-Aware Contrastive Learning with Hierarchical Information Bottleneck for Multimodal Sentiment Analysis

Abstract

In multimodal sentiment analysis, textual, acoustic, and visual modalities often contain redundant and noisy information. Such information increases model complexity and weakens core sentiment representations, degrading accuracy and robustness. To address this issue, we propose CLIBN, a multimodal sentiment recognition network based on contrastive learning and information bottleneck. First, we design a sentimentintensity-aware contrastive learning strategy. It constructs positive and negative pairs according to sentiment intensity distances and assigns adaptive weights to different pairs, enabling the model to capture fine-grained sentiment differences. Second, we introduce a hierarchical information bottleneck module. It treats text as the primary modality and progressively integrates complementary cues from acoustic and visual modalities, while preserving task-relevant semantics and suppressing redundant information. Experimental results on CMU-MOSI and CMU-MOSEI show that CLIBN achieves superior performance. Specifically, Acc-2 reaches 87.8% and 86.7%, and F1-Score reaches 87.8% and 86.6% on the two datasets, respectively. These results demonstrate the effectiveness of CLIBN for multimodal sentiment representation learning.