EEG Classification using Semi Supervised Learning

The major challenge in the current brain-computer interface research is the accurate classification of time varying electroencephalographic EEG signals. The labeled EEG samples are usually scarce, while the unlabeled samples are available in large quantities and easy to collect in real applications. Semi supervised learning SSL methods can utilize both labeled and unlabeled data to improve performance over supervised approaches. However, it has been reported that the unlabeled data may undermine the performance of SSL in some cases. This study proposes a three stages technique for automatic detection of epileptic seizure in EEG signals. In practical application of pattern recognition, there are often diverse features extracted from raw data which needs to be recognized. Proposed method is based on time series signal, spectral analysis and recurrent neural networks RNNs . Decision making was performed in three stages i feature extraction using Welch method power spectrum density estimation PSD ii dimensionality reduction using statistics over extracted features and time series signal samples iii EEG classification using recurrent neural networks. This study shows that Welch method power spectrum density estimation is an appropriate feature which well represents EEG signals. We achieved higher classification accuracy specificity, sensitivity, classification accuracy in comparison with other researches to classify EEG signals exactly 100 in this study. To improve the safety of SSL, we proposed a new safety control mechanism by analyzing the differences between unlabeled data analysis in supervised and semi supervised learning. We then develop and implement a safe classification method based on the semi supervised extreme learning machine SS ELM . Following this approach, the Wasserstein distance is used to measure the similarities between the predictions obtained from ELM and SS ELM algorithms, and a different risk degree is thereby calculated for each unlabeled data instance. A risk based regularization term is then constructed and embedded into the objective function of the SS ELM. Extensive experiments were conducted using benchmark and EEG datasets to evaluate the effectiveness of the proposed method. Experimental results show that the performance of the new algorithm is comparable to SS ELM and superior to ELM on average. It is thereby shown that the proposed method is safe and efficient for the classification of EEG signals. Shivshankar Kumar Yadav | Veena S. "EEG Classification using Semi Supervised Learning" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-3 , April 2019, URL: https://www.ijtsrd.com/papers/ijtsrd23355.pd