A Deep Learning Method for Improving the Classification Accuracy of SSMVEP-Based BCI

Zhongke Gao, Tao Yuan, Xinjun Zhou, Chao Ma, Kai Ma, Pan Hui

Abstract: Steady State Motion Visual Evoked Potential (SSMVEP)-based Brain Computer Interface (BCI) is widely studied and has been used to varies of occasions on account of its good performance, mild stimulation, and free of additional training. We design a trolley control system based on SSMVEP signals and observe a phenomenon named “BCI Illiterate,” in which case some subjects present unsatisfactory performance with low classification accuracies. In order to cope with this challenging problem in real-world contexts, we introduce a deep learning (DL) method. The method allows improving the accuracies for both EEG literate and EEG illiterate. In particular, we firstly conduct SSMVEP experiments to obtain EEG signals from 10 subjects, including 5 EEG literates and 5 EEG illiterates. Then we construct a convolutional neural network with long short-term memory (CNN-LSTM) framework, which allows extracting the spectral, spatial, and temporal features of EEG signals, to realize the high classification accuracies of SSMVEP signals. The results show that DL method can reach 96.83% and 91.86% for EEG literate and EEG illiterate respectively, which are 12.68% and 31.08% higher than the results of traditional methods. These results indicate that DL method is not only suitable for EEG literate, but more importantly, can greatly improve the performance for EEG illiterate, which finally can enhance the robustness and universality of the SSMVEP-based BCI.