Organizations: 1Tsinghua University · 3Qwen Team, Alibaba Group · University of South California · University of California San Diego · Zhejiang University · Shanghai Jiao Tong University
The cold-start initialization stage plays a pivotal role in training Multimodal Large Reasoning Models (MLRMs), yet its mechanisms remain insufficiently understood. To analyze this stage, we introduce the Visual Attention Score (VAS), an attention-based metric that quantifies how much a model attends to visual tokens. We find that reasoning performance is strongly correlated with VAS (r=0.9616): models with higher VAS achieve substantially stronger multimodal reasoning. Surprisingly, multimodal cold-start fails to elevate VAS, resulting in attention distributions close to the base model, whereas text-only cold-start leads to a clear increase. We term this counter-intuitive phenomenon Lazy Attention Localization. To validate its causal role, we design training-free interventions that directly modulate attention allocation during inference, performance gains of 1−2% without any retraining. Building on these insights, we further propose Attention-Guided Visual Anchoring and Reflection (AVAR), a comprehensive cold-start framework that integrates visual-anchored data synthesis, attention-guided objectives, and visual-anchored reward shaping. Applied to Qwen2.5-VL-7B, AVAR achieves an average gain of 7.0% across 7 multimodal reasoning benchmarks. Ablation studies further confirm that each component of AVAR contributes step-wise to the overall gains. The code, data, and models are available at https://github.com/lrlbbzl/Qwen-AVAR.
Figures & tables
Figure 1: Analysis of different models’ performance and Visual Attention Score (VAS) distribution. (a) Model performance by mean VAS; (b) VAS distribution across layers.
Figure 2: Performance gains from training-free attention modulation on MathVista, MathVision and MathVerse-VO.
Figure 3: Overview of Visual-Anchored Reflection data synthesis in 3 steps: Visual Description, Reflection-Enhanced Reasoning, and Visual Anchor Integration.
Configuration
Method Components
Benchmark Performance
VARD
AGTO
VARS
MathVista
MathVision
MathVerse-VO
MMStar
MMMU-VAL
MMMU-Pro
Hallusion.
Avg.
Baseline (Qwen2.5-VL-7B)
68.2
25.2
41.1
62.1
58.1
38.3
50.7
49.1
✓
70.6
32.9
43.5
61.1
55.2
38.7
55.3
51.0
✓
✓
72.0
34.1
44.0
62.8
58.3
39.8
57.2
52.6
AVAR-Thinker
✓
✓
✓
74.7
37.4
50.4
64.1
63.8
42.9
59.5
56.1
Table 2: Ablation study of our proposed components. Starting from the baseline, we show the performance impact of adding different modules, indicated by a checkmark (✓).
Method
Benchmark Performance
Avg.
MathVista
MathVision
MathVerse-VO
MMStar
MMMU-val
MMMU-Pro
Hallusion.
Baseline (Qwen2.5-VL-7B)
68.2
25.2
41.1
62.1
58.1
38.3
50.7
49.1
+ R1-OneVision
63.3
26.3
39.7
54.9
49.9
34.6
43.8
44.6
+ OpenVLThinker
68.9
25.3
37.8
58.7
55.7
36.0
54.1
48.1
+ Vision-SR1
67.6
27.9
42.3
46.9
50.7
36.3
42.1
44.8
+ VARD (Ours)
70.6
32.9
43.5
61.1
55.2
38.7
55.3
51.0
Table 3: Comparison of our Visual-Anchored Reflection Data (VAR) against other data-centric cold-start methods. The best scores are bold ; the second best are underlined .
Model
VAS
Avg. Performance
Qwen2.5-VL-7B
7.5
49.3
Qwen2.5-VL-7B + VARD Data
10.1
51.0
AVAR-CS
13.8
52.6
AVAR-Thinker
18.9
56.1
Table 4: Evolution of VAS and performance across AVAR training stages.
Appendix figures & tables7 assets
Supplementary material from the paper’s appendix.
Appendix
Configuration
Method Components
Benchmark Performance
VARD
AGTO
VARS
MathVista
MathVision
MathVerse-VO
MMStar
MMMU-VAL
MMMU-Pro
HallusionBench
Avg.
Baseline (Llama-3.2-11B-Vision-Instruct)
48.6
19.7
18.4
49.8
50.7
33.0
40.3
37.2
✓
56.6
25.5
25.4
58.0
55.2
36.4
45.5
43.2
✓
✓
57.4
25.2
26.6
58.8
56.2
37.0
46.4
44.0
AVAR-Thinker
✓
✓
✓
61.7
26.9
29.0
61.8
58.6
38.9
50.1
46.7
Appendix
Table 5: Ablation study of our proposed components on Llama-3.2-11B-Vision-Instruct model.
Figure 4: Attention allocation of Qwen2.5-VL-7B, R1-OneVision and OVR-CS on Mathvista.
Figure 5: Attention allocation of ThinkLite-VL, RevisualR1-CS and MIMO-VL-CS on Mathvista.
Figure 6: Attention allocation of Qwen2.5-VL, Vision-R1 and OVR-CS on Mathvision.
Cold-start
RL
Hyperparameter
Value
Hyperparameter
Value
Cutoff length
30,000
Max response length
30,000
Epochs
20
Weight decay
3×10−5
Learning rate
5×10−6
Learning rate
1×10−6
Warm-up ratio
0.1
Warm-up ratio
0.03
Batch size
512
Batch size
256
Appendix
Table 6: Hyperparameter search spaces used in experiments.
Figure 7: AVAR-Thinker on MathVerse-VO: A showcase demonstrating its powerful visual perception and reflective capabilities.