Graph neural networks (GNNs) have pioneered advancements in graph representation learning, exhibiting superior feature learning and performance over multilayer perceptrons (MLPs) when handling graph inputs. However, understanding the feature learning aspect of GNNs is still in its initial stage. This study aims to bridge this gap by investigating the role of graph convolution within the context of feature learning theory in neural networks using gradient descent training. We provide a distinct characterization of signal learning and noise memorization in two-layer graph convolutional networks (GCNs), contrasting them with two-layer convolutional neural networks (CNNs). Our findings reveal that graph convolution significantly augments the benign overfitting regime over the counterpart CNNs, where signal learning surpasses noise memorization, by approximately factor $\sqrt{D}^{q-2}$, with $D$ denoting a node's expected degree and $q$ being the power of the ReLU activation function where $q > 2$. These findings highlight a substantial discrepancy between GNNs and MLPs in terms of feature learning and generalization capacity after gradient descent training, a conclusion further substantiated by our empirical simulations.

本研究旨在通过研究梯度下降训练中神经网络中的特征学习理论中图卷积的作用，提供了两层图卷积网络与两层卷积神经网络之间的信号学习和噪声记忆的不同表征，发现图卷积显着增强了对手CNN的良性过拟合的范围，并且在梯度下降训练后， GNNs和MLPs在特征学习和泛化能力方面存在重大差异，这一结论在我们的实证模拟中得到了进一步证实。

图神经网络从结构信息中可得证明的益处：视作特征学习角度