VAT: Vision Action Transformer by Unlocking Full Representation of ViT
Wenhao Li, Chengwei Ma, Weixin Mao

TL;DR
The paper introduces VAT, a novel Vision Transformer architecture that utilizes the full feature hierarchy for improved robotic perception and manipulation, achieving state-of-the-art results on LIBERO benchmarks.
Contribution
VAT extends ViT to process features across all layers, enabling deep perception-action fusion and improving robotic manipulation performance.
Findings
VAT achieves 98.15% success rate on LIBERO benchmarks.
VAT outperforms prior methods like OpenVLA-OFT.
Leveraging full feature hierarchy enhances robotic policy learning.
Abstract
In robot learning, Vision Transformers (ViTs) are standard for visual perception, yet most methods discard valuable information by using only the final layer's features. We argue this provides an insufficient representation and propose the Vision Action Transformer (VAT), a novel architecture that is extended from ViT and unlocks the full feature hierarchy of ViT. VAT processes specialized action tokens with visual features across all transformer layers, enabling a deep and progressive fusion of perception and action generation. On a suite of simulated manipulation tasks, VAT achieves a 98.15\% average success rate across four LIBERO benchmarks, establishing a new state-of-the-art by outperforming prior methods like OpenVLA-OFT. Our work presents not only a powerful model for imitation learning but also demonstrates the critical importance of leveraging the complete ''representation…
Peer Reviews
Decision·Submitted to ICLR 2026
The idea behind action tokens cross attending on vision tokens in the full ViT hierarchy is nice.
1. Overall the main idea behind the paper is simple and offers very limited novelty. In many cases in the past features from various layers (not only for ViTs) can also be used for various tasks. The heatmap visualizations do not offer any additional insights and are kinda underwhelming as a support for the claim by the authors. The authors need significantly more experiments to validate their claims. 2. There is no established protocol regarding the experiments in Table 3. It is unclear how th
1. The paper presents a super simple idea for extending standard ViT into robot policies by using action modules parall to ViT blocks. 2. The paper is very well written. 3. The paper shows good performance improvement on the Libero benchmark compared to other state of the art methods.
1. Is it really about features from lower layers? The paper motivates the use of parallel action modules by lack of finegrained details in the features of the final layer of the ViT. However, the action module is also sequential and the final action prediction only depends on the features from the last action module. My question is why would the action module retain any of the lower layer features and the ViT would not? This could be understood better by probing the final layer features of Vi
Strengths: - The underutilization of intermediate ViT representations for robotic policy learning makes sense to utilize richer representations. - Introducing action tokens across all ViT layers enables progressive perception-action coupling without manual layer selection - this is a conceptually simple idea. The simulation results show the effectiveness of it. - Achieves 98.15% mean success rate on LIBERO and outperforms strong baselines such as OpenVLA-OFT. - Offers both ablation and visualiza
Weakness: - All results are in simulation on one benchmark. It's not clear whether this method will transfer to a real-world robot setting. Considering that this is the main application domain of this paper, I feel that this is very necessary to convince the audience. - There are no runtime, memory, or scalability comparisons versus alternatives (e.g., external/internal fusion or frozen ViT baselines). I assume that the proposed method will require more resources, but there is no substantial dis
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Taxonomy
TopicsRobot Manipulation and Learning · Multimodal Machine Learning Applications · Human Pose and Action Recognition
