G1: Bootstrapping Perception and Reasoning Abilities of Vision-Language Model via Reinforcement Learning
Liang Chen, Hongcheng Gao, Tianyu Liu, Zhiqi Huang, Flood Sung, Xinyu Zhou, Yuxin Wu, Baobao Chang
TL;DR
The paper tackles the challenge of translating vision-language models into effective decision-making within visually rich, interactive environments. It introduces VLM-Gym, a scalable RL platform with four visual games, and two model series, G0 (RL-only) and G1 (perception-enhanced cold start with distillation), to study how perception and reasoning co-evolve during training. G0 demonstrates emergent perception and reasoning that surpasses several strong baselines, while G1 achieves even stronger performance, outperforming the teacher and Claude-3.7-Sonnet-Thinking. A key finding is that perception and reasoning mutually bootstrap each other during RL, suggesting general strategies for advancing VLMs as capable interactive agents. The work provides open-source tools and insights that could significantly impact multimodal RL research and practical autonomous agents in visually complex domains.
Abstract
Vision-Language Models (VLMs) excel in many direct multimodal tasks but struggle to translate this prowess into effective decision-making within interactive, visually rich environments like games. This ``knowing-doing'' gap significantly limits their potential as autonomous agents, as leading VLMs often performing badly in simple games. To address this, we introduce VLM-Gym, a curated reinforcement learning (RL) environment featuring diverse visual games with unified interfaces and adjustable, compositional difficulty, specifically designed for scalable multi-game parallel training. Leveraging VLM-Gym, we train G0 models using pure RL-driven self-evolution, which demonstrate emergent perception and reasoning patterns. To further mitigate challenges arising from game diversity, we develop G1 models. G1 incorporates a perception-enhanced cold start prior to RL fine-tuning. Our resulting G1 models consistently surpass their teacher across all games and outperform leading proprietary models like Claude-3.7-Sonnet-Thinking. Systematic analysis reveals an intriguing finding: perception and reasoning abilities mutually bootstrap each other throughout the RL training process. Source code including VLM-Gym and RL training are released at https://github.com/chenllliang/G1 to foster future research in advancing VLMs as capable interactive agents.
