Marco Congedo1, Louis Korczowski2, Arnaud Delorme3, Fernando Lopes da Silva4. 1. GIPSA-lab, CNRS and Grenoble Alpes University, Grenoble, France. Electronic address: marco.congedo@gmail.com. 2. GIPSA-lab, CNRS and Grenoble Alpes University, Grenoble, France. 3. Université de Toulouse, UPS, Centre de Recherche Cerveau et Cognition, Toulouse, France; CNRS, CerCo, France; Swartz Center for Computational Neurosciences, UCSD, La Jolla, CA, USA. 4. Center of Neuroscience, Swammerdam Institute for Life Sciences, Amsterdam, The Netherlands.
Abstract
BACKGROUND: Already used at the incept of research on event-related potentials (ERP) over half a century ago, the arithmetic mean is still the benchmark for ERP estimation. Such estimation, however, requires a large number of sweeps and/or a careful rejection of artifacts affecting the electroencephalographic recording. NEW METHOD: In this article we propose a method for estimating ERPs as they are naturally contaminated by biological and instrumental artifacts. The proposed estimator makes use of multivariate spatio-temporal filtering to increase the signal-to-noise ratio. This approach integrates a number of relevant advances in ERP data analysis, such as single-sweep adaptive estimation of amplitude and latency and the use of multivariate regression to account for ERP overlapping in time. RESULTS: We illustrate the effectiveness of the proposed estimator analyzing a dataset comprising 24 subjects involving a visual odd-ball paradigm, without performing any artifact rejection. COMPARISON WITH EXISTING METHOD(S): As compared to the arithmetic average, a lower number of sweeps is needed. Furthermore, artifact rejection can be performed roughly using permissive automatic procedures. CONCLUSION: The proposed ensemble average estimator yields a reference companion to the arithmetic ensemble average estimation, suitable both in clinical and research settings. The method can be applied equally to event related fields (ERF) recorded by means of magnetoencephalography. In this article we describe all necessary methodological details to promote testing and comparison of this proposed method by peers. Furthermore, we release a MATLAB toolbox, a plug-in for the EEGLAB software suite and a stand-alone executable application.
BACKGROUND: Already used at the incept of research on event-related potentials (ERP) over half a century ago, the arithmetic mean is still the benchmark for ERP estimation. Such estimation, however, requires a large number of sweeps and/or a careful rejection of artifacts affecting the electroencephalographic recording. NEW METHOD: In this article we propose a method for estimating ERPs as they are naturally contaminated by biological and instrumental artifacts. The proposed estimator makes use of multivariate spatio-temporal filtering to increase the signal-to-noise ratio. This approach integrates a number of relevant advances in ERP data analysis, such as single-sweep adaptive estimation of amplitude and latency and the use of multivariate regression to account for ERP overlapping in time. RESULTS: We illustrate the effectiveness of the proposed estimator analyzing a dataset comprising 24 subjects involving a visual odd-ball paradigm, without performing any artifact rejection. COMPARISON WITH EXISTING METHOD(S): As compared to the arithmetic average, a lower number of sweeps is needed. Furthermore, artifact rejection can be performed roughly using permissive automatic procedures. CONCLUSION: The proposed ensemble average estimator yields a reference companion to the arithmetic ensemble average estimation, suitable both in clinical and research settings. The method can be applied equally to event related fields (ERF) recorded by means of magnetoencephalography. In this article we describe all necessary methodological details to promote testing and comparison of this proposed method by peers. Furthermore, we release a MATLAB toolbox, a plug-in for the EEGLAB software suite and a stand-alone executable application.
Authors: Anne Guérin-Dugué; Raphaëlle N Roy; Emmanuelle Kristensen; Bertrand Rivet; Laurent Vercueil; Anna Tcherkassof Journal: Front Psychol Date: 2018-07-12