Bridging Visual Representation and Reinforcement Learning from Verifiable Rewards in Large Vision-Language Models
Organizations: EPIC Lab, SJTU · HKUST (GZ) · Huawei
Abstract
Reinforcement Learning from Verifiable Rewards (RLVR) has substantially enhanced the reasoning capabilities of large language models in abstract reasoning tasks. However, its application to Large Vision-Language Models (LVLMs) remains constrained by a structural representational bottleneck. Existing approaches generally lack explicit modeling and effective utilization of visual information, preventing visual representations from being tightly coupled with the reinforcement learning optimization process and thereby limiting further improvements in multimodal reasoning performance. To address this limitation, we propose KAWHI (Key-Region Aligned Weighted Harmonic Incentive), a plug-and-play reward reweighting mechanism that explicitly incorporates structured visual information into uniform reward policy optimization methods (e.g., GRPO and GSPO). The method adaptively localizes semantically salient regions through hierarchical geometric aggregation, identifies vision-critical attention heads via structured attribution, and performs paragraph-level credit reallocation to align spatial visual evidence with semantically decisive reasoning steps. Extensive empirical evaluations on diverse reasoning benchmarks substantiate KAWHI as a general-purpose enhancement module, consistently improving the performance of various uniform reward optimization methods. Project page: KAWHI (https://kawhiiiileo.github.io/KAWHI_PAGE/)
Figures & tables
| Method | MathVista | MathVerse | MathVision | WeMath | Avg |
| Qwen2.5-VL-7B-Instruct | |||||
| Base | 67.47 | 45.56 | 23.36 | 54.32 | 47.68 |
| fine-grained reward | |||||
| Step-GRPO | 66.87 0.60 | 44.32 1.24 | 24.76 1.40 | 55.32 1.00 | 47.82 0.14 |
| FT-RL | 67.68 0.21 | 46.88 1.32 | 26.12 2.76 | 56.78 2.46 | 49.37 1.69 |
| VPPO | 68.42 0.95 | 47.21 1.65 | 28.42 5.06 | 57.12 2.80 | 50.29 2.61 |
| Method | CharXiv Desc | CharXiv Rea | Chart QA | Chart QAPro | Chart Mimic |
| Qwen2.5-VL-7B-Instruct | 67.9 | 42.1 | 87.4 | 41.9 | 40.2 |
| + GRPO | 70.1 2.2 | 44.3 2.2 | 88.3 0.9 | 43.7 1.8 | 42.8 2.6 |
| + GRPO + KAWHI (Ours) | 72.2 4.3 | 46.4 4.3 | 89.1 1.7 | 45.3 3.4 | 45.1 4.9 |
| Ablation | Experiment | MathVerse (%) | MathVision (%) | Average |
| – | GRPO | 45.94 ↓1.62 | 28.29 ↓0.99 | 37.11 |
| – | GRPO+ KAWHI (Ours) | 47.56 | 29.28 | 38.42 |
| ① Region Selection | All vision tokens | 46.58 ↓0.98 | 28.45 ↓0.83 | 37.52 |
| Random | 46.34 ↓1.22 | 28.98 ↓0.30 | 37.66 | |
| Inverse selection | 45.74 ↓1.82 | 27.82 ↓1.46 | 36.78 | |
| ② Reward Metric | Key–Key | 47.08 ↓0.48 | 28.95 ↓0.33 | 38.02 |
Appendix figures & tables1 asset
Supplementary material from the paper’s appendix.
Appendix
VLM Reasoning
Vision-language model reasoning studies how multimodal systems use visual evidence and language to answer questions, plan, and explain.
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