An efficient rhythmic component expression and weighting synthesis strategy for classifying motor imagery EEG in a brain-computer interface.

Full Abstract

The recognition of mental states during motor imagery tasks is crucial for EEG-based brain-computer interface research. We have developed a new algorithm by means of frequency decomposition and weighting synthesis strategy for recognizing imagined right- and left-hand movements. A frequency range from 5 to 25 Hz was divided into 20 band bins for each trial, and the corresponding envelopes of filtered EEG signals for each trial were extracted as a measure of instantaneous power at each frequency band. The dimensionality of the feature space was reduced from 200 (corresponding to 2 s) to 3 by down-sampling of envelopes of the feature signals, and subsequently applying principal component analysis. The linear discriminate analysis algorithm was then used to classify the features, due to its generalization capability. Each frequency band bin was weighted by a function determined according to the classification accuracy during the training process. The present classification algorithm was applied to a dataset of nine human subjects, and achieved a success rate of classification of 90% in training and 77% in testing. The present promising results suggest that the present classification algorithm can be used in initiating a general-purpose mental state recognition based on motor imagery tasks.

Author information

Author/s: Wang, Tao (T); He, Bin (B);

Affiliation: Department of Bioengineering, University of Illinois at Chicago, IL 60607, USA.

Grants: R01EB00178 (Agency:NIBIB NIH HHS)

Journal and publication information

Publication Type: Clinical Trial; Journal Article; Research Support, U.S. Gov't, Non-P.H.S.; Research Support, U.S. Gov't, P.H.S.

Journal: Journal of neural engineering (J Neural Eng), published in England. (Language: eng)

Reference: 2004-Mar; vol 1 (issue 1) : pp 1-7

Dates: Created 2005/05/06; Completed 2005/05/31; Revised 2007/11/14;

PMID: 15876616, status: MEDLINE (last retrieval date: 2/18/2009, IMS Date: )

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