MCNN-CMCA: A multiscale convolutional neural networks with cross-modal channel attention for physiological signal-based mental state recognition

Human mental state recognition (MSR) has significant implications for human-machine interactions. Although mental state recognition models based on single-modality signals, such as electroencephalogram (EEG) or peripheral physiological signals (PPS), have achieved encouraging progress, methods leveraging multimodal physiological signals still need to be explored. In this study, we present MCNN-CMCA, a generic model that employs multiscale convolutional neural networks (CNNs) with cross-modal channel attention to realize physiological signals-based MSR. Specifically, we first design an innovative cross-modal channel attention mechanism that adaptively adjusting the weights of each signal channel, effectively learning both intra-modality and inter-modality correlation and expanding the channel information to the depth dimension. Additionally, the study utilizes multiscale temporal CNNs for obtaining short-term and long-term time-frequency features across different modalities. Finally, the multimodal fusion module integrates the representations of all physiological signals and the classification layer implements sparse connections by setting the mask weights to 0. We evaluate the proposed method on the SEED-VIG, DEAP, and self-made datasets, achieving superior results compared to existing state-of-the-art methods. Furthermore, we conduct ablation studies to demonstrate the effectiveness of each component in the MCNN-CMCA and show the use of multimodal physiological signals outperforms single-modality signals.