🤖 AI Summary
This work addresses the task of sarcasm explanation generation in multimodal dialogue, focusing on modeling fine-grained emotional contrasts across textual, visual, and acoustic modalities to enhance sarcasm interpretability. We propose an emotion-enhanced context–emotion heterogeneous graph structure, introducing (i) a lexicon-guided textual emotion reasoning module and (ii) a novel Joint Cross-modal Attention-based Sarcasm Inference (JCA-SI) module to uniformly capture heterogeneous modality-wise emotional relationships. Our framework integrates the BART generative architecture, lexicon-augmented sentiment analysis, and an extended JCA cross-modal attention mechanism. Evaluated on the WITS dataset, our method significantly outperforms state-of-the-art approaches. Both automatic metrics and human evaluation confirm that the proposed emotion graph modeling substantially improves the accuracy, consistency, and comprehensibility of generated sarcasm explanations—establishing a new paradigm for multimodal sarcasm understanding.
📝 Abstract
Sarcasm Explanation in Dialogue (SED) is a new yet challenging task, which aims to generate a natural language explanation for the given sarcastic dialogue that involves multiple modalities (ie utterance, video, and audio). Although existing studies have achieved great success based on the generative pretrained language model BART, they overlook exploiting the sentiments residing in the utterance, video and audio, which play important roles in reflecting sarcasm that essentially involves subtle sentiment contrasts. Nevertheless, it is non-trivial to incorporate sentiments for boosting SED performance, due to three main challenges: 1) diverse effects of utterance tokens on sentiments; 2) gap between video-audio sentiment signals and the embedding space of BART; and 3) various relations among utterances, utterance sentiments, and video-audio sentiments. To tackle these challenges, we propose a novel sEntiment-enhanceD Graph-based multimodal sarcasm Explanation framework, named EDGE. In particular, we first propose a lexicon-guided utterance sentiment inference module, where a heuristic utterance sentiment refinement strategy is devised. We then develop a module named Joint Cross Attention-based Sentiment Inference (JCA-SI) by extending the multimodal sentiment analysis model JCA to derive the joint sentiment label for each video-audio clip. Thereafter, we devise a context-sentiment graph to comprehensively model the semantic relations among the utterances, utterance sentiments, and video-audio sentiments, to facilitate sarcasm explanation generation. Extensive experiments on the publicly released dataset WITS verify the superiority of our model over cutting-edge methods.