1. Covariate shift estimation based adaptive ensemble learning for handling non-stationarity in motor imagery related EEG-based brain-computer interface
- Author
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Dheeraj Rathee, Shang-Ming Zhou, Haider Raza, Hubert Cecotti, and Girijesh Prasad
- Subjects
FOS: Computer and information sciences ,0209 industrial biotechnology ,Covariate shift ,CSE, Covariate shift estimation ,Computer science ,CSV, Covariate shift validation ,EEG, Electroencephalography ,SSL, Semi-supervised learning ,NSL, Non-stationary learning ,02 engineering and technology ,Electroencephalography ,DWEC, Dynamically weighted ensemble classification ,Machine Learning (cs.LG) ,020901 industrial engineering & automation ,MI, Motor imagery ,CSP, Common spatial pattern ,Statistics - Machine Learning ,RSM, Random subspace method ,0202 electrical engineering, electronic engineering, information engineering ,CS, Covariate shift ,CSW, Covariate shift warning ,BCI, Brain-computer-interface ,medicine.diagnostic_test ,FB, Frequency band ,PWKNN, Probabilistic weighted K-nearest neighbour ,FBCSP, Filter bank common spatial pattern ,Computer Science Applications ,CSE-UAEL, CSE-based unsupervised adaptive ensemble learning ,Principal component analysis ,020201 artificial intelligence & image processing ,QA75 ,KNN, K-nearest-neighbors ,Cognitive Neuroscience ,Machine Learning (stat.ML) ,ERS, Desynchronization ,Article ,Motor imagery ,Artificial Intelligence ,Ensemble learning ,Covariate ,ERD, Synchronization ,medicine ,Brain–computer interface ,PCA, Principal component analysis ,Brain-computer interface (BCI) ,business.industry ,Pattern recognition ,Electroencephalogram (EEG) ,CSA, Covariate shift adaptation ,Computer Science - Learning ,ComputingMethodologies_PATTERNRECOGNITION ,RC0321 ,Non-stationary learning ,Artificial intelligence ,business ,Classifier (UML) ,EWMA, exponential weighted moving average ,LDA, Linear discriminant analysis - Abstract
The non-stationary nature of electroencephalography (EEG) signals makes an EEG-based brain-computer interface (BCI) a dynamic system, thus improving its performance is a challenging task. In addition, it is well-known that due to non-stationarity based covariate shifts, the input data distributions of EEG-based BCI systems change during inter- and intra-session transitions, which poses great difficulty for developments of online adaptive data-driven systems. Ensemble learning approaches have been used previously to tackle this challenge. However, passive scheme based implementation leads to poor efficiency while increasing high computational cost. This paper presents a novel integration of covariate shift estimation and unsupervised adaptive ensemble learning (CSE-UAEL) to tackle non-stationarity in motor-imagery (MI) related EEG classification. The proposed method first employs an exponentially weighted moving average model to detect the covariate shifts in the common spatial pattern features extracted from MI related brain responses. Then, a classifier ensemble was created and updated over time to account for changes in streaming input data distribution wherein new classifiers are added to the ensemble in accordance with estimated shifts. Furthermore, using two publicly available BCI-related EEG datasets, the proposed method was extensively compared with the state-of-the-art single-classifier based passive scheme, single-classifier based active scheme and ensemble based passive schemes. The experimental results show that the proposed active scheme based ensemble learning algorithm significantly enhances the BCI performance in MI classifications., 28 Pages, 3 figures, Neurocomputing
- Published
- 2019