🤖 AI Summary
This work addresses the high training costs and low inference efficiency of existing vision-language-action (VLA) models, which rely heavily on large-scale annotated data—such as chain-of-thought reasoning or visual grounding labels—to enable explicit reasoning. To overcome these limitations, we propose ATA, a plug-and-play, training-free framework that introduces implicit reasoning into VLA for the first time. ATA dynamically fuses visual information through attention-guided, action-driven regions of interest (RoIs), adaptively refining input representations without requiring additional annotations or architectural modifications. Extensive experiments demonstrate that our approach significantly improves task success rates and robustness across multiple benchmarks while maintaining or even enhancing inference efficiency.
📝 Abstract
Vision-Language-Action (VLA) models rely on current observations, including images, language instructions, and robot states, to predict actions and complete tasks. While accurate visual perception is crucial for precise action prediction and execution, recent work has attempted to further improve performance by introducing explicit reasoning during inference. However, such approaches face significant limitations. They often depend on data-intensive resources such as Chain-of-Thought (CoT) style annotations to decompose tasks into step-by-step reasoning, and in many cases require additional visual grounding annotations (e.g., bounding boxes or masks) to highlight relevant image regions. Moreover, they involve time-consuming dataset construction, labeling, and retraining, which ultimately results in longer inference sequences and reduced efficiency. To address these challenges, we propose ATA, a novel training-free framework that introduces implicit reasoning into VLA inference through complementary attention-guided and action-guided strategies. Unlike CoT or explicit visual-grounding methods, ATA formulates reasoning implicitly by integrating attention maps with an action-based region of interest (RoI), thereby adaptively refining visual inputs without requiring extra training or annotations. ATA is a plug-and-play implicit reasoning approach for VLA models, lightweight yet effective. Extensive experiments show that it consistently improves task success and robustness while preserving, and even enhancing, inference efficiency.