AffectAgent: Collaborative Multi-Agent Reasoning for Retrieval-Augmented Multimodal Emotion Recognition
Authors: Zeheng Wang, Zitong Yu, Yijie Zhu, Bo Zhao, Haochen Liang, Taorui Wang, Wei Xia, Jiayu Zhang, +4 more
Organizations: Guangdong Laboratory of Artificial Intelligence and Digital Economy (SZ), Shenzhen, Guangdong, China · Great Bay University, Dongguan, Guangdong, China · Guangdong Provincial Key Laboratory of Intelligent Information Processing & Shenzhen Key Laboratory of Media Security, Shenzhen University, Shenzhen, Guangdong, China
LLM-based multimodal emotion recognition relies on static parametric memory and often hallucinates when interpreting nuanced affective states. In this paper, given that single-round retrieval-augmented generation is highly susceptible to modal ambiguity and therefore struggles to capture complex affective dependencies across modalities, we introduce AffectAgent, an affect-oriented multi-agent retrieval-augmented generation framework that leverages collaborative decision-making among agents for fine-grained affective understanding. Specifically, AffectAgent comprises three jointly optimized specialized agents, namely a query planner, an evidence filter, and an emotion generator, which collaboratively perform analytical reasoning to retrieve cross-modal samples, assess evidence, and generate predictions. These agents are optimized end-to-end using Multi-Agent Proximal Policy Optimization (MAPPO) with a shared affective reward to ensure consistent emotion understanding. Furthermore, we introduce Modality-Balancing Mixture of Experts (MB-MoE) and Retrieval-Augmented Adaptive Fusion (RAAF), where MB-MoE dynamically regulates the contributions of different modalities to mitigate representation mismatch caused by cross-modal heterogeneity, while RAAF enhances semantic completion under missing-modality conditions by incorporating retrieved audiovisual embeddings. Extensive experiments on MER-UniBench demonstrate that AffectAgent achieves superior performance across complex scenarios. Our code will be released at: https://github.com/Wz1h1NG/AffectAgent.
Figures & tables
Figure 1. (a) Vanilla LLMs ( Lian et al., 2025 ; Cheng et al., 2024a ) rely on static memory, struggling with nuanced emotion understanding. (b) Traditional RAG-enhanced models ( Pipoli et al., 2025 ; Wen et al., 2025 ) follow a linear retrieve-then-generate pipeline, which is inadequate for complex emotional reasoning. (c) Our AffectAgent adopts a collaborative multi-agent architecture that orchestrates query planning, retrieval, filtering, and generation for emotion recognition.
Figure 2. Overview of AffectAgent. AffectAgent performs multimodal emotion recognition through collaborative multi-agent reasoning, including affect-oriented query planning, evidence adjudication, and emotion generation. Meanwhile, RAAF and MB-MoE improve cross-modal fusion by recovering missing information and balancing modality contributions. Block diagram of AffectAgent. Multimodal inputs are processed by query-planning, evidence-adjudication, and emotion-generation agents, while RAAF recovers missing information and MB-MoE balances the contributions of available modalities.
Model
Modality
Basic
Sentiment
Fine-grained
Mean
A
V
T
MER2023
MER2024
MELD
IEMOCAP
MOSI
MOSEI
SIMS
SIMS v2
OV-MERD+
Video-LLaMA ( Zhang et al., 2023a )
✓
✓
✓
14.52
13.56
17.65
15.68
54.55
46.52
58.56
56.32
13.98
32.37
+ AffectAgent
22.75 ↑ 8.23
22.71 ↑ 9.15
24.07 ↑ 6.42
23.49 ↑ 7.81
58.90 ↑ 4.35
52.14 ↑ 5.62
61.70 ↑ 3.14
60.40 ↑ 4.08
22.65 ↑ 8.67
38.75 ↑ 6.38
VideoChat ( Li et al., 2025a )
✓
✓
✓
16.89
15.65
19.55
16.98
56.02
48.65
59.68
57.65
15.02
34.01
+ AffectAgent
24.30 ↑ 7.41
23.87 ↑ 8.22
25.38 ↑ 5.83
23.93 ↑ 6.95
61.14 ↑ 5.12
54.96 ↑ 6.31
63.93 ↑ 4.25
61.53 ↑ 3.88
22.36 ↑ 7.34
40.15 ↑ 6.14
ChatBridge ( Zhao et al., 2023 )
✓
✓
✓
18.06
16.89
20.35
25.02
56.66
49.68
58.62
56.55
15.35
35.24
Table 1. Results on MER-UniBench . For each dataset, we report its primary evaluation metric. The gray-shaded columns denote the primary ranking metrics, the best results are highlighted in bold, and the second-best results are underlined. Our AffectAgent consistently outperforms different baseline models.
Model
Modality
Basic
Sentiment
Fine-grained
Mean
A
V
T
MER2023
MER2024
MELD
IEMOCAP
MOSI
MOSEI
SIMS
SIMS v2
OV-MERD+
PandaGPT ( Su et al., 2023 )
✓
✓
×
28.15
32.40
26.50
31.20
55.30
52.10
54.20
50.50
25.40
39.53
+ AffectAgent
32.27 ↑ 4.12
35.95 ↑ 3.55
31.71 ↑ 5.21
36.03 ↑ 4.83
57.45 ↑ 2.15
54.94 ↑ 2.84
56.12 ↑ 1.92
52.91 ↑ 2.41
29.76 ↑ 4.36
43.01 ↑ 3.48
Emotion-LLaMA ( Cheng et al., 2024a )
✓
✓
×
45.20
56.80
35.40
42.10
56.50
58.20
65.30
64.10
40.50
51.57
+ AffectAgent
49.01 ↑ 3.81
58.94 ↑ 2.14
39.52 ↑ 4.12
45.66 ↑ 3.56
58.73 ↑ 2.23
60.65 ↑ 2.45
67.16 ↑ 1.86
66.02 ↑ 1.92
44.35 ↑ 3.85
54.44 ↑ 2.87
AffectGPT ( Lian et al., 2025 )
✓
✓
×
65.20
66.80
48.50
52.40
72.10
70.30
78.40
76.50
52.60
64.76
Table 2. Robustness evaluation under missing-modality settings. A , V , and T denote audio, video, and text, respectively. Results show that AffectAgent consistently improves performance across different backbone models under various missing-modality conditions.
Method
Basic
Sentiment
Fine-grained
Mean
MER2023
MER2024
MELD
IEMOCAP
MOSI
MOSEI
SIMS
SIMS v2
OV-MERD+
No RAG
78.54
78.80
55.65
60.54
81.30
80.90
88.49
86.18
62.52
74.77
Rewrite-Retrieve-Read ( Ma et al., 2023 )
78.39
78.76
55.58
60.42
81.36
80.83
88.52
86.13
62.47
74.72
BGM ( Ke et al., 2024 )
78.68
79.03
55.88
60.77
81.62
81.18
88.73
86.41
62.81
75.01
RAG-DDR ( Li et al., 2025b )
79.12
79.38
56.33
61.27
81.98
81.54
89.13
86.82
63.21
75.42
AffectAgent (Ours)
80.69 ↑ 2.15
80.66 ↑ 1.86
59.07 ↑ 3.42
63.39 ↑ 2.85
82.73 ↑ 1.43
82.67 ↑ 1.77
89.43 ↑ 0.94
87.33 ↑ 1.15
65.13 ↑ 2.61
76.78 ↑ 2.01
Table 3. Performance comparison of different RAG methods on emotion recognition datasets. To ensure a fair comparison, all RAG methods are applied to the same MLLM using full-modality inputs (audio, video, and text). Our proposed AffectAgent consistently outperforms existing RAG baselines across all datasets.
Figure 3. Illustration of three representative case studies, showing smooth success, query deviation with a correct final prediction, and query deviation with an incorrect final prediction. Three qualitative examples trace AffectAgent from its generated query through retrieved evidence and reasoning to the final emotion prediction. The examples show a smooth success, a deviated query with a correct prediction, and a deviated query with an incorrect prediction.
SFT
Retrieval
MER2023
MER2024
HIT ↑
Δ HIT
HIT ↑
Δ HIT
×
×
20.24
—
18.32
—
✓
×
24.12
+3.88
22.45
+4.13
✓
Naive RAG
26.58
+6.34
24.71
+6.39
✓
AffectAgent
28.80
+8.56
27.53
+9.21
Table 4. Stepwise effectiveness of our components. We utilize the generic MLLM Video-LLaMA2 as the base model. Δ HIT indicates the absolute improvement over the zero-shot baseline.
Planner
Filter
Confuse Evid.
Counter Evid.
MER2023
MER2024
HIT ↑
Δ HIT
HIT ↑
Δ HIT
×
✓
✓
✓
27.15
−1.65
25.86
−1.67
✓
×
✓
✓
27.94
−0.86
26.65
−0.88
×
×
✓
✓
26.58
−2.22
24.71
−2.82
✓
✓
×
×
27.42
−1.38
26.11
−1.42
✓
✓
✓
×
28.11
−0.69
26.75
−0.78
Table 5. Ablation on Multi-Agent coordination and Evidence Structures based on Video-LLaMA2. All variants retain primary evidence. Δ HIT indicates the performance drop compared to the full framework.
Figure 4. Visualization of RAAF and MB-MoE in AffectAgent on sampled MER2023 data with AffectGPT as the backbone. (a) Performance gain (pp) under different retrieval conditions. (b) Average expert routing weights under different input states. Two plots summarize the fusion modules. The first compares performance gains under different retrieval conditions, and the second compares average MB-MoE expert-routing weights for different modality input states.
Guangdong University of Technology Guangzhou, China · Southern University of Science and Technology Shenzhen, China · Xi’an Jiaotong University Xi’an, China +1
School of Information Science and Technology, Guangdong University of Foreign Studies, Guangdong, China · School of Information Science and Engineering, Lanzhou University, Lanzhou, China · School of Computer Science and Engineering, Sun Yat-sen University, Guangdong, China +2