title: Aggregation of sparse linear discriminant analyses for event-related potential classification in brain-computer interface.
abstract: Two main issues for event-related potential (ERP) classification in brain-computer interface (BCI) application are curse-of-dimensionality and bias-variance tradeoff, which may deteriorate classification performance, especially with insufficient training samples resulted from limited calibration time. This study introduces an aggregation of sparse linear discriminant analyses (ASLDA) to overcome these problems. In the ASLDA, multiple sparse discriminant vectors are learned from differently l1-regularized least-squares regressions by exploiting the equivalence between LDA and least-squares regression, and are subsequently aggregated to form an ensemble classifier, which could not only implement automatic feature selection for dimensionality reduction to alleviate curse-of-dimensionality, but also decrease the variance to improve generalization capacity for new test samples. Extensive investigation and comparison are carried out among the ASLDA, the ordinary LDA and other competing ERP classification algorithms, based on different three ERP datasets. Experimental results indicate that the ASLDA yields better overall performance for single-trial ERP classification when insufficient training samples are available. This suggests the proposed ASLDA is promising for ERP classification in small sample size scenario to improve the practicability of BCI.
authors.affiliation: Key Laboratory for Advanced Control and Optimization for Chemical Processes, East China University of Science and Technology, Shanghai, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.forename: Guoxu
authors.initials: G
authors.lastname: Zhou
authors.forename: Jing
authors.initials: J
authors.lastname: Jin
authors.forename: Qibin
authors.initials: Q
authors.lastname: Zhao
authors.forename: Xingyu
authors.initials: X
authors.lastname: Wang
authors.forename: Andrzej
authors.initials: A
authors.lastname: Cichocki
mesh_terms: D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D062207:Brain-Computer Interfaces; D016208:Databases, Factual / Q000706:statistics & numerical data; D016002:Discriminant Analysis; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology*; D006801:Humans; D012372:ROC Curve