Title :
Unsupervised short-term covariate shift minimization for self-paced BCI
Author :
Mohammadi, Reza ; Mahloojifar, Ali ; Coyle, D.
Author_Institution :
Biomed. Eng. Dept., Tarbiat Modares Univ., Tehran, Iran
Abstract :
A major challenge for Brain Computer Interface systems (BCIs) is dealing with non-stationarity in the EEG signal. There are two types of EEG non-stationarities 1) long-term changes related to fatigue, changes in recording conditions or effects of feedback training which is addressed in classification step and 2) short-term changes related to different mental activities and drifts in slow cortical potentials which can be addressed in the feature extraction step. In this paper we use a covariate shift minimization (CSM) method to alleviate the short-term (single trial) effects of EEG non-stationarity to improve the performance of self-paced BCIs in detecting foot movement from the continuous EEG signal. The results of applying this unsupervised covariate shift minimization with two different classifiers, linear discriminant analysis (LDA) and probabilistic classification vector machines (PCVMs) along with two different filtering methods (constant bandwidth and constant-Q filters) show the considerable improvement in system performance.
Keywords :
brain-computer interfaces; electroencephalography; feedback; filtering theory; medical signal processing; probability; EEG signal; LDA; PCVM; brain computer interface systems; constant-Q filters; feedback training; filtering methods; linear discriminant analysis; probabilistic classification vector machines; self-paced BCI; unsupervised short-term covariate shift minimization; Brain-computer interfaces; Electroencephalography; Feature extraction; Foot; Minimization; Polynomials; Training; Covariate shift minimization; EEG; Non-stationarity; Self-paced Brain Computer interfaces;
Conference_Titel :
Computational Intelligence, Cognitive Algorithms, Mind, and Brain (CCMB), 2013 IEEE Symposium on
Conference_Location :
Singapore
DOI :
10.1109/CCMB.2013.6609172