IGCN: Integrative Graph Convolutional Networks for Multi-modal Data

Recent advances in Graph Neural Networks (GNN) have led to a considerable growth in graph data modeling for multi-modal data which contains various types of nodes and edges. Although some integrative prediction solutions have been developed recently for network-structured data, these methods have some restrictions. For a node classification task involving multi-modal data, certain data modalities may perform better when predicting one class, while others might excel in predicting a different class. Thus, to obtain a better learning representation, advanced computational methodologies are required for the integrative analysis of multi-modal data. Moreover, existing integrative tools lack a comprehensive and cohesive understanding of the rationale behind their specific predictions, making them unsuitable for enhancing model interpretability. Addressing these restrictions, we introduce a novel integrative neural network approach for multi-modal data networks, named Integrative Graph Convolutional Networks (IGCN). IGCN learns node embeddings from multiple topologies and fuses the multiple node embeddings into a weighted form by assigning attention coefficients to the node embeddings. Our proposed attention mechanism helps identify which types of data receive more emphasis for each sample to predict a certain class. Therefore, IGCN has the potential to unravel previously unknown characteristics within different node classification tasks. We benchmarked IGCN on several datasets from different domains, including a multi-omics dataset to predict cancer subtypes and a multi-modal clinical dataset to predict the progression of Alzheimer's disease. Experimental results show that IGCN outperforms or is on par with the state-of-the-art and baseline methods.