A Generalization of ViT/MLP-Mixer to Graphs
Xiaoxin HeBryan HooiThomas LaurentAdam PeroldYann LeCunXavier Bresson
Generalizes vision transformer and MLP-Mixer architectures to graph representation learning, offering a linear-complexity model that mitigates over-squashing, models long-range dependencies, and achieves 3-WL expressive power.
Graph Neural Networks (GNNs) are critical tools for modeling relational data in domains such as drug discovery, chemistry, social networks, and computer vision. However, standard message-passing architectures struggle with two significant issues: poor long-range dependency and over-squashing, where exponentially growing neighborhood information is compressed into fixed-size vectors. While Graph Transformers address these challenges using global attention mechanisms, they introduce quadratic computational complexity relative to the number of nodes, making them inefficient and prohibitively expensive for large graphs.
The article evaluates a new framework that adapts vision-based ViT and MLP-Mixer architectures to graph learning, creating the Graph ViT/MLP-Mixer class of models. The primary objective is to demonstrate that this architecture can capture long-range interactions, achieve high expressive power, and maintain linear computational and memory complexity without relying on costly full-graph attention mechanisms.
To achieve this, the approach partitions graphs into overlapping sub-graph patches using a fast clustering algorithm (METIS expanded by one hop) to preserve critical boundary edges. A local message-passing neural network encodes each patch into a vector representation, and explicit node and patch positional encodings maintain spatial relationships. Alternating token-mixing and channel-mixing layers then combine information across all patches and feature dimensions in linear time. The authors validated the framework across four simulated datasets (evaluating graph isomorphism and over-squashing) and seven real-world benchmarks spanning molecular property prediction, image superpixels, and large peptide structures, comparing performance, runtime, and memory usage against standard message-passing and transformer baselines.
The key findings show that the proposed model delivers state-of-the-art accuracy while dramatically reducing computational overhead. First, on the Long Range Graph Benchmark (Peptides-func and Peptides-struct), the model achieved top scores (0.6970 Average Precision and 0.2449 Mean Absolute Error), significantly outperforming standard message-passing baselines. Second, it demonstrated linear scalability, consuming up to 18 to 20 times less memory and running up to 43 times faster per epoch than leading expressive graph models like SUN on large graphs. Third, the framework effectively mitigated over-squashing on the synthetic TreeNeighbourMatch benchmark, generalizing successfully up to a tree depth of seven where standard models failed at depth four. Finally, the architecture achieved 100% accuracy on simulated isomorphism datasets (CSL, EXP, and SR25), demonstrating empirical expressive power at the level of higher-order Weisfeiler-Leman tests.
These results demonstrate that attention mechanisms are not strictly necessary to capture long-range dependencies in graph learning. Organizations can achieve state-of-the-art predictive accuracy with linear resource scaling, substantially reducing hardware requirements, training times, and operational costs for large-scale graph analytics. Furthermore, the framework acts as a versatile plugin, consistently improving the performance of various underlying message-passing encoders.
Organizations evaluating or deploying graph learning models should consider adopting patch-based mixer architectures as a lightweight, scalable alternative to Graph Transformers for long-range reasoning tasks. To implement the method effectively, practitioners should use overlapping patch extraction rather than disjoint partitioning and leverage on-the-fly partition perturbations during training to regularize the model and prevent overfitting.
Confidence in these findings is strong across the evaluated benchmarks, but practical limitations remain. The number of graph clusters must currently be chosen as a fixed parameter, which can cause the model to process graphs of variable sizes at inconsistent structural resolutions. Additionally, the high expressive power demonstrated in the article remains empirical without formal mathematical guarantees, and large-scale pre-training across wider domain benchmarks has yet to be evaluated.
- Paper: How Powerful are Graph Neural Networks?, Keyulu Xu et al. (2019). This paper establishes the theoretical Weisfeiler-Lehman expressiveness limits of message-passing GNNs, providing the essential foundation for evaluating the 3-WL expressiveness of Graph ViT/MLP-Mixer.
- Paper: Do Transformers Really Perform Badly for Graph Representation?, Chengxuan Ying et al. (2021). This work demonstrates how global Transformer architectures overcome message-passing limits on graphs, motivating the need for more efficient ViT- and MLP-Mixer-based graph models.
- Paper: Weisfeiler and Leman Go Neural: Higher-Order Graph Neural Networks, Christopher Morris et al. (2019). It introduces higher-order Weisfeiler-Leman graph neural networks, which define the expressivity benchmarks surpassed or matched by the source paper.
- Paper: Benchmarking Graph Neural Networks, Vijay Prakash Dwivedi et al. (2023). It provides the standardized benchmarking suite and experimental protocols used to evaluate the efficiency and expressiveness of new graph architectures.
- Paper: Measuring and Relieving the Over-smoothing Problem for Graph Neural Networks from the Topological View, Deli Chen et al. (2019). This study analyzes the over-smoothing bottleneck inherent to deep message passing, highlighting one of the central problems Graph ViT/MLP-Mixer is designed to solve.
- Paper: Semi-Supervised Classification with Graph Convolutional Networks, Thomas N. Kipf et al. (2017). It introduces the standard local message-passing graph convolutional network whose structural bottlenecks motivate alternative global mixer architectures.
- Paper: Graph Attention Networks, Petar Veličković et al. (2018). It establishes graph attention mechanisms for neighbor aggregation, which serve as a foundational comparison point for global attention and mixing on graphs.
- Paper: Specformer: Spectral Graph Neural Networks Meet Transformers, Deyu Bo et al. (2023). This paper explores an alternative spectral-domain attention mechanism that addresses long-range dependencies and over-smoothing in graphs.
