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Mohammad Souri & Sassan Azadi

Improving BCI performance using SSA and GA

(Volume 85 - Année 2016 — Actes de colloques — Special edition)
Open Access

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Brain Computer Interface (BCI) systems based on motor imagery tasks have significant usage for disabled people for their life style. Electroencephalogram (EEG) is one of the best approach to obtain human brain signals. The EEG signal requires three stages of preprocessing, feature extraction, and classification to increase signal analysis accuracy. Due to different task of brain, EEG distribution fluctuates (non-stationary), and therefore challenges BCI for many researchers. Recently a method named stationary subspace analysis (SSA) applied to some BCI data by some research teams in order to separate stationary and non-stationary parts of EEG. However they did not obtain significantly results. This method factorizes EEG into its stationary and non-stationary components by dividing signal into number of epochs, and compares their data distributions. In this study, we applied SSA in preprocessing stage into train and test data of the BCI competition dataset of nine healthy people. We applied the Genetic Algorithm (GA) to train our Artificial Neural Network (ANN) classifier. We also inspect different parameters for SSA to improve the performance. Our results indicate significant growth especially for subjects with worse results in other techniques (improving ~40% to ~70%). In addition, the mean of accuracies improves 5% in regard to the winner of competition.

Keywords : artificial neural network, BCI, classification, feature extraction, genetic algorithm, motor imagery, stationary subspace analysis

To cite this article

Mohammad Souri & Sassan Azadi, «Improving BCI performance using SSA and GA», Bulletin de la Société Royale des Sciences de Liège [En ligne], Volume 85 - Année 2016, Actes de colloques, Special edition, 1204 - 1210 URL :

About: Mohammad Souri

Department of Biomedical Engineering, Semnan University, Semnan, Iran

About: Sassan Azadi

Department of Biomedical Engineering, Semnan University, Semnan, Iran,