Authors: Zehui Xiao, Yi Zheng, Guixing Fu, Wenkai Lu, Lingfei He, Tao Tan, Yue Liu, Silun Wang, Junhai Xu, Mengting Liu
Organizations: School of Biomedical Engineering, Shenzhen Campus of Sun Yat-sen University, Shenzhen 518107, China · School of Computer Science and Technology, Tianjin University, Tianjin 300354, China · Faculty of Applied Sciences, Macao Polytechnic University, Macao, China · Shenzhen Dr. Brain Technologies Co., Ltd., Shenzhen 518057, China
Cross-subject generalization remains a major challenge for EEG-based emotion recognition due to pronounced inter-subject variability in neural activity and emotion-related spatiotemporal patterns. Existing methods mainly alleviate inter subject differences through distribution alignment or contrastive learning, while paying limited attention to representation bias associated with fixed spatiotemporal modeling orders. We hypothesize that high-level emotion representations of the same EEG signal should remain consistent across different spatiotemporal modeling paths. Based on this hypothesis, we propose a Dual-Path Spatiotemporal Contrastive Learning (DP-STCL) framework for cross-subject EEG emotion recognition. DP-STCL employs two complementary encoders with independent parameters, namely a Temporal-to-Spatial (TS) path and a Spatial to-Temporal (ST) path, to model EEG spatiotemporal information under different integration orders. During representation learning, the same emotional stimulus is used to establish cross subject associations, while three complementary relations jointly constrain representation variations across subjects and modeling paths. This promotes stable and discriminative stimulus-related emotion representations. To further handle limited labeled target subject data, we introduce a LoRA-based few-shot adaptation strategy with low parameter overhead. Extensive cross-subject experiments on SEED, SEED-IV, SEED-V, and FACED show that DP-STCL consistently outperforms the compared methods, demonstrating its effectiveness in improving cross-subject EEG emotion recognition.
Figures & tables
Fig. 1: Overall framework of the proposed DP-STCL for cross-subject EEG emotion recognition. The framework consists of cross-subject pretraining with dual-path spatiotemporal encoding, same-path cross-subject contrastive learning, and cross-path semantic alignment, followed by few-shot subject adaptation with LoRA and emotion recognition for the target subject.
Fig. 2: Illustration of the multiscale dilated temporal convolution module. Parallel temporal convolution branches with different dilation rates capture temporal dependencies at multiple receptive-field scales, and their outputs are concatenated to form the enhanced representation.
Fig. 3: Illustration of the proposed collaborative representation learning scheme, including same-path cross-subject contrastive learning and cross-path semantic alignment.
Method
SEED (Acc%)
SEED-IV (Acc%)
SEED-V (Acc%)
DE+MLP
79.9±8.7
59.3±17.2
59.3±17.2
DSAN [ 43 ]
84.1±7.6
62.2±14.2
59.3±16.8
DMMR [ 44 ]
88.3±5.6
72.7±8.0
/
MS-MDA [ 45 ]
84.5±7.5
64.3±11.1
58.2±12.3
ADAST [ 46 ]
87.3±2.1
53.7±13.6
50.7±14.0
GMoE [ 47 ]
84.6±9.3
71.2±8.5
76.3±9.2
TABLE I: Cross-Subject Emotion Recognition Performance on the SEED, SEED-IV, and SEED-V Datasets. Results marked with † are reproduced; others are from original papers.
Method
FACED (cls2) (Acc%)
FACED (cls9) (Acc%)
Source of Result
DE+MLP
60.9±3.2
21.7±2.2
Baseline
SimCLR
/
30.2±2.7
Reproduced Results in [ 33 ]
MSHCL
77.0±3.6
45.7±3.4
Original Results in [ 50 ]
CLISA
67.8±4.1
42.4±3.1
Reproduced Results in [ 13 ]
DAEST
77.8±5.8
62.3±8.1
Reproduced Results in [ 51 ]
DP-STCL
80.5±4.4
66.5±7.8
Results from this paper
TABLE II: Cross-Subject Emotion Recognition Performance on the FACED Dataset
Fig. 4: Confusion matrices for emotion classification on the SEED, SEED-IV, SEED-V, and FACED datasets.
Training Strategy
Test Repr.
SEED (Acc%)
SEED-IV (Acc%)
SEED-V (Acc%)
FACED cls2 (Acc%)
FACED cls9 (Acc%)
Single-Path Independent Training
ST-only
88.9±9.2
73.5±9.5
73.6±12.5
78.5±4.5
63.0±7.5
TS-only
87.1±9.4
74.3±9.9
74.2±10.8
78.0±4.2
62.5±7.0
DP-STCL Dual-Path Joint Training
ST
89.5±10.5
74.9±9.1
75.2±12.3
79.8±4.5
64.1±7.4
TS
89.3±11.0
75.7±9.9
75.3±10.7
79.0±4.5
64.0±7.0
TS+ST
90.3±10.2
76.8±10.4
79.0±11.4
80.5±4.4
66.5±7.8
TABLE III: Ablation Results for Dual-Path Spatiotemporal Modeling and the Joint Training Mechanism
Fig. 5: Subject-wise accuracy distribution of dual-path spatiotemporal modeling.
Fig. 6: Performance comparison of different cross-path learning strategies across datasets.
Fig. 7: Sensitivity analysis of the cross-path semantic alignment weight λ across datasets.
Dataset
Method
3-shot (Acc%)
5-shot (Acc%)
10-shot (Acc%)
SEED
LoRA
91.1±7.9
91.2±7.9
91.3±7.5
Head-only
77.8±10.4
79.8±9.2
79.9±10.7
Full-finetune
91.6±7.2
92.8±6.2
94.3±5.1
SEED-IV
LoRA
77.2±9.6
77.9±8.4
83.6±5.5
Head-only
63.1±9.5
60.8±10.8
62.7±10.1
Full-finetune
77.5±9.3
78.6±8.4
85.8±5.9
TABLE IV: Comparison of Classification Accuracy under Different Few-Shot Settings and Parameter Update Strategies
Fig. 8: t-SNE visualization of the representations extracted by the TS branch, ST branch, and fused TS+ST representation on the five emotion recognition tasks.
School of Biomedical Engineering, Shenzhen Campus of Sun Yat-sen University, Shenzhen 518107, China · School of Computer Science and Technology, Tianjin University, Tianjin 300354, China