Group-common and individual-specific effects of structure-function coupling in human brain networks with graph neural networks.

The human cerebral cortex is organized into functionally segregated but synchronized regions bridged by the structural connectivity of white matter pathways. While structure-function coupling has been implicated in cognitive development and neuropsychiatric disorders, studies yield inconsistent findings. The extent to which the structure-function coupling reflects reliable individual differences or primarily group-common characteristics remains unclear, at both the global and regional brain levels. By leveraging two independent, high-quality datasets, we found that the graph neural network accurately predicted unseen individuals' functional connectivity from structural connectivity, reflecting a strong structure-function coupling. This coupling was primarily driven by network topology and was substantially stronger than that of the linear models. Moreover, we observed that structure-function coupling was dominated by group-common effects, with subtle yet significant individual-specific effects. The regional group and individual effects of coupling were hierarchically organized across the cortex along a sensorimotor-association axis, with lower group and higher individual effects in association cortices. These findings emphasize the importance of considering both group and individual effects in understanding cortical structure-function coupling, suggesting insights into interpreting individual differences of the coupling and informing connectivity-guided therapeutics.

Pose-Guided Hierarchical Graph Reasoning for 3-D Hand Pose Estimation From a Single Depth Image.

Estimating 3-D hand pose estimation from a single depth image is important for human-computer interaction. Although depth-based 3-D hand pose estimation has made great progress in recent years, it is still difficult to deal with some complex scenes, especially the issues of serious self-occlusion and high self-similarity of fingers. Inspired by the fact that multipart context is critical to alleviate ambiguity, and constraint relations contained in the hand structure are important for the robust estimation, we attempt to explicitly model the correlations between different hand parts. In this article, we propose a pose-guided hierarchical graph convolution (PHG) module, which is embedded into the pixelwise regression framework to enhance the convolutional feature maps by exploring the complex dependencies between different hand parts. Specifically, the PHG module first extracts hierarchical fine-grained node features under the guidance of hand pose and then uses graph convolution to perform hierarchical message passing between nodes according to the hand structure. Finally, the enhanced node features are used to generate dynamic convolution kernels to generate hierarchical structure-aware feature maps. Our method achieves state-of-the-art performance or comparable performance with the state-of-the-art methods on five 3-D hand pose datasets: 1) HANDS 2019; 2) HANDS 2017; 3) NYU; 4) ICVL; and 5) MSRA.

A Dual-Branch Self-Boosting Framework for Self-Supervised 3D Hand Pose Estimation.

Although 3D hand pose estimation has made significant progress in recent years with the development of the deep neural network, most learning-based methods require a large amount of labeled data that is time-consuming to collect. In this paper, we propose a dual-branch self-boosting framework for self-supervised 3D hand pose estimation from depth images. First, we adopt a simple yet effective image-to-image translation technology to generate realistic depth images from synthetic data for network pre-training. Second, we propose a dual-branch network to perform 3D hand model estimation and pixel-wise pose estimation in a decoupled way. Through a part-aware model-fitting loss, the network can be updated according to the fine-grained differences between the hand model and the unlabeled real image. Through an inter-branch loss, the two complementary branches can boost each other continuously during self-supervised learning. Furthermore, we adopt a refinement stage to better utilize the prior structure information in the estimated hand model for a more accurate and robust estimation. Our method outperforms previous self-supervised methods by a large margin without using paired multi-view images and achieves comparable results to strongly supervised methods. Besides, by adopting our regenerated pose annotations, the performance of the skeleton-based gesture recognition is significantly improved.