Abstract:Developing interpretable models for diagnosing neurodevelopmental disorders (NDDs) is highly valuable yet challenging, primarily due to the complexity of encoding, decoding and integrating imaging and non-imaging data. Many existing machine learning models struggle to provide comprehensive interpretability, often failing to extract meaningful biomarkers from imaging data, such as functional magnetic resonance imaging (fMRI), or lacking mechanisms to explain the significance of non-imaging data. In this paper, we propose the Interpretable Information Bottleneck Heterogeneous Graph Neural Network (I2B-HGNN), a novel framework designed to learn from fine-grained local patterns to comprehensive global multi-modal interactions. This framework comprises two key modules. The first module, the Information Bottleneck Graph Transformer (IBGraphFormer) for local patterns, integrates global modeling with brain connectomic-constrained graph neural networks to identify biomarkers through information bottleneck-guided pooling. The second module, the Information Bottleneck Heterogeneous Graph Attention Network (IB-HGAN) for global multi-modal interactions, facilitates interpretable multi-modal fusion of imaging and non-imaging data using heterogeneous graph neural networks. The results of the experiments demonstrate that I2B-HGNN excels in diagnosing NDDs with high accuracy, providing interpretable biomarker identification and effective analysis of non-imaging data.
Abstract:Decoding neural visual representations from electroencephalogram (EEG)-based brain activity is crucial for advancing brain-machine interfaces (BMI) and has transformative potential for neural sensory rehabilitation. While multimodal contrastive representation learning (MCRL) has shown promise in neural decoding, existing methods often overlook semantic consistency and completeness within modalities and lack effective semantic alignment across modalities. This limits their ability to capture the complex representations of visual neural responses. We propose Neural-MCRL, a novel framework that achieves multimodal alignment through semantic bridging and cross-attention mechanisms, while ensuring completeness within modalities and consistency across modalities. Our framework also features the Neural Encoder with Spectral-Temporal Adaptation (NESTA), a EEG encoder that adaptively captures spectral patterns and learns subject-specific transformations. Experimental results demonstrate significant improvements in visual decoding accuracy and model generalization compared to state-of-the-art methods, advancing the field of EEG-based neural visual representation decoding in BMI. Codes will be available at: https://github.com/NZWANG/Neural-MCRL.