title: Mixed-norm regularization for brain decoding.
abstract: This work investigates the use of mixed-norm regularization for sensor selection in event-related potential (ERP) based brain-computer interfaces (BCI). The classification problem is cast as a discriminative optimization framework where sensor selection is induced through the use of mixed-norms. This framework is extended to the multitask learning situation where several similar classification tasks related to different subjects are learned simultaneously. In this case, multitask learning helps in leveraging data scarcity issue yielding to more robust classifiers. For this purpose, we have introduced a regularizer that induces both sensor selection and classifier similarities. The different regularization approaches are compared on three ERP datasets showing the interest of mixed-norm regularization in terms of sensor selection. The multitask approaches are evaluated when a small number of learning examples are available yielding to significant performance improvements especially for subjects performing poorly.
authors.affiliation: Laboratoire Lagrange, UMR7293, Université de Nice, 00006 Nice, France.
authors.forename: R
authors.initials: R
authors.lastname: Flamary
authors.affiliation: Gipsa Lab, Domaine Universitaire BP 46, 38402 Saint Martin d'Hères, France.
authors.forename: N
authors.initials: N
authors.lastname: Jrad
authors.affiliation: Gipsa Lab, Domaine Universitaire BP 46, 38402 Saint Martin d'Hères, France.
authors.forename: R
authors.initials: R
authors.lastname: Phlypo
authors.affiliation: Gipsa Lab, Domaine Universitaire BP 46, 38402 Saint Martin d'Hères, France.
authors.forename: M
authors.initials: M
authors.lastname: Congedo
authors.affiliation: LITIS, EA 4108-INSA, Université de Rouen, 76000 Rouen, France.
authors.forename: A
authors.initials: A
authors.lastname: Rakotomamonjy
mesh_terms: D000465:Algorithms; D019540:Area Under Curve; D001185:Artificial Intelligence; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods*; D062207:Brain-Computer Interfaces; D003198:Computer Simulation; D005071:Evoked Potentials; D006801:Humans; D015233:Models, Statistical; D015203:Reproducibility of Results; D012984:Software