Random Subspace Ensembles for fMRI Classification

Classification of brain images obtained through functional magnetic resonance imaging (fMRI) poses a serious challenge to pattern recognition and machine learning due to the extremely large feature-to-instance ratio. This calls for revision and adaptation of the current state-of-the-art classification methods. We investigate the suitability of the random subspace (RS) ensemble method for fMRI classification. RS samples from the original feature set and builds one (base) classifier on each subset. The ensemble assigns a class label by either majority voting or averaging of output probabilities. Looking for guidelines for setting the two parameters of the method--ensemble size and feature sample size--we introduce three criteria calculated through these parameters: usability of the selected feature sets, coverage of the set of "important" features, and feature set diversity. Optimized together, these criteria work toward producing accurate and diverse individual classifiers. RS...

• Type: Journal
• Year: 2010
• Where: TMI
• Authors: Ludmila I. Kuncheva, Juan José Rodríguez Diez, Catrin O. Plumpton, David E. J. Linden, Stephen J. Johnston
• Keywords: FMRI, Functional Magnetic Resonance, Management, State-of-the-art Classification Methods, TMI 2010