title: Asynchronous Detection of Trials Onset from Raw EEG Signals.
abstract: Clinical processing of event-related potentials (ERPs) requires a precise synchrony between the stimulation and the acquisition units that are guaranteed by means of a physical link between them. This precise synchrony is needed since temporal misalignments during trial averaging can lead to high deviations of peak times, thus causing error in diagnosis or inefficiency in classification in brain-computer interfaces (BCIs). Out of the laboratory, mobile EEG systems and BCI headsets are not provided with the physical link, thus being inadequate for acquisition of ERPs. In this study, we propose a method for the asynchronous detection of trials onset from raw EEG without physical links. We validate it with a BCI application based on the dichotic listening task. The user goal was to attend the cued auditory message and to report three keywords contained in it while ignoring the other message. The BCI goal was to detect the attended message from the analysis of auditory ERPs. The rate of successful onset detection in both synchronous (using the real onset) and asynchronous (blind detection of trial onset from raw EEG) was 73% with a synchronization error of less than 1[Formula: see text]ms. The level of synchronization provided by this proposal would allow home-based acquisition of ERPs with low cost BCI headsets and any media player unit without physical links between them.
authors.affiliation: 1 Department of Signal Theory, Telematics and Communications, University of Granada, Spain.|2 Nicolo Association, Churriana de la Vega, Granada, Spain.
authors.forename: M A
authors.initials: MA
authors.lastname: Lopez-Gordo
authors.affiliation: 3 Institute of Bioengineering, University Miguel Hernández and CIBER BBN Av. de la Universidad 03202, Elche, Spain.
authors.forename: M D
authors.initials: MD
authors.lastname: Grima Murcia
authors.affiliation: 4 Department of Signal Theory, Communications and Networking, University of Granada 18071, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Padilla
authors.affiliation: 5 Department of Computer Architecture and Technology, University of Granada, c/Periodista Daniel Saucedo 18071, Granada, Spain.
authors.forename: F
authors.initials: F
authors.lastname: Pelayo
authors.affiliation: 3 Institute of Bioengineering, University Miguel Hernández and CIBER BBN Av. de la Universidad 03202, Elche, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Fernandez
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D001288:Attention / Q000502:physiology; D001921:Brain / Q000502:physiology*; D062207:Brain-Computer Interfaces; D003463:Cues; D004569:Electroencephalography / Q000379:methods*; D005071:Evoked Potentials; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D012815:Signal Processing, Computer-Assisted; D013067:Speech Perception / Q000502:physiology; D013686:Telemetry / Q000379:methods*; D013997:Time Factors; D055815:Young Adult
keywords: EEG teleservices; Event-related potentials; brain area network; brain-computer interface; e-health