A Review of Multimodal Explainable Artificial Intelligence: Past, Present and Future

Artificial intelligence (AI) has rapidly developed through advancements in computational power and the growth of massive datasets. However, this progress has also heightened challenges in interpreting the "black-box" nature of AI models. To address these concerns, eXplainable AI (XAI) has emerged with a focus on transparency and interpretability to enhance human understanding and trust in AI decision-making processes. In the context of multimodal data fusion and complex reasoning scenarios, the proposal of Multimodal eXplainable AI (MXAI) integrates multiple modalities for prediction and explanation tasks. Meanwhile, the advent of Large Language Models (LLMs) has led to remarkable breakthroughs in natural language processing, yet their complexity has further exacerbated the issue of MXAI. To gain key insights into the development of MXAI methods and provide crucial guidance for building more transparent, fair, and trustworthy AI systems, we review the MXAI methods from a historical perspective and categorize them across four eras: traditional machine learning, deep learning, discriminative foundation models, and generative LLMs. We also review evaluation metrics and datasets used in MXAI research, concluding with a discussion of future challenges and directions. A project related to this review has been created at https://github.com/ShilinSun/mxai_review.

Line Graph Contrastive Learning for Link Prediction

Link prediction task aims to predict the connection of two nodes in the network. Existing works mainly predict links by node pairs similarity measurements. However, if the local structure doesn't meet such measurement assumption, the algorithms' performance will deteriorate rapidly. To overcome these limitations, we propose a Line Graph Contrastive Learning (LGCL) method to obtain multiview information. Our framework obtains a subgraph view by h-hop subgraph sampling with target node pairs as the center. After transforming the sampled subgraph into a line graph, the edge embedding information is directly accessible, and the link prediction task is converted into a node classification task. Then, different graph convolution operators learn representations from double perspectives. Finally, contrastive learning is adopted to balance the subgraph representations of these perspectives via maximizing mutual information. With experiments on six public datasets, LGCL outperforms current benchmarks on link prediction tasks and shows better generalization performance and robustness.