Multimodal sentiment analysis has attracted extensive research attention as increasing numbers of users share images and texts to express their emotions and opinions on social media. Collecting large amounts of labeled sentiment data is an expensive and challenging task due to the high cost of labeling and unavoidable label ambiguity. Semi-supervised learning (SSL) is explored to utilize the extensive unlabeled data to alleviate the demand for annotation. However, unlike typical multimodal tasks, sentiment inconsistency between image and text degrades the performance of SSL algorithms. To address the issue, we propose SCRD, the first semi-supervised framework for image-text sentiment recognition. To better utilize the discriminative features of each modality, we decouple features into common and private parts. We then use the private features to train unimodal classifiers for enhanced modality-specific sentiment representation. Considering the complex relationships between modalities, we devise a modal selection-based attention module that adaptively identifies the dominant sentiment modality at the sample level to guide multimodal fusion. Furthermore, to prevent model predictions from over-relying on common features under the guidance of multimodal labels, we design a pseudo-label filtering strategy based on the matching degree of prediction and dominant modality. Extensive experiments and comparisons on five publicly available datasets demonstrate that SCRD outperforms state-of-the-art methods. Our code is released on https://github.com/wuyou-xia/Seek-Common-Ground-While-Reserving-Differences.

Multimodal large language models (MLLMs) recently showed strong capacity in integrating data among multiple modalities, empowered by generalizable attention architecture. Advanced methods predominantly focus on language-centric tuning while less exploring multimodal tokens mixed through attention, posing challenges in high-level tasks that require fine-grained cognition and emotion understanding. In this work, we identify the attention deficit disorder problem in multimodal learning, caused by inconsistent cross-modal attention and layer-by-layer decayed attention activation. To address this, we propose a novel attention mechanism, termed MOdular Duplex Attention (MODA), simultaneously conducting the inner-modal refinement and inter-modal interaction. MODA employs a correct-after-align strategy to effectively decouple modality alignment from cross-layer token mixing. In the alignment phase, tokens are mapped to duplex modality spaces based on the basis vectors, enabling the interaction between visual and language modality. Further, the correctness of attention scores is ensured through adaptive masked attention, which enhances the model's flexibility by allowing customizable masking patterns for different modalities. Extensive experiments on 21 benchmark datasets verify the effectiveness of MODA in perception, cognition, and emotion tasks.

In online chatting, people increasingly prefer using stickers to supplement or replace text for replies, as sticker images can express vivid and varied emotions. The Sticker Response Selection (SRS) task aims to predict the sticker image that is most relevant to the history dialogue. Previous researches explore the semantic similarity between context and stickers, overlooking both unimodal and cross-modal emotional information. In this paper, we propose a 'Perceive before Respond' (PBR) training paradigm. PBR perceives sticker emotions through a knowledge distillation module. Variety representations of each emotion category are acquired from the large-scale sticker emotion recognition dataset and distilled into our model to enhance emotion comprehension. We further distinguish stickers with similar subject elements under the same topic. We perform contrastive learning at both inter- and intra-topic levels to obtain discriminative and diverse sticker representations. In addition, we improve the hard negative sampling method for image-text matching based on cross-modal sentiment association, conducting hard sample mining from both semantic similarity and sentiment polarity similarity for sticker-to-dialogue and dialogue-to-sticker. Extensive experiments verify the effectiveness of each proposed component. Ablation experiments on different backbone networks demonstrate the generality of our approach. Our code is released on https://github.com/wuyou-xia/Perceive-before-Respond.