title: Towards a truly mobile auditory brain-computer interface: exploring the P300 to take away.
abstract: In a previous study we presented a low-cost, small, and wireless 14-channel EEG system suitable for field recordings (Debener et al., 2012, psychophysiology). In the present follow-up study we investigated whether a single-trial P300 response can be reliably measured with this system, while subjects freely walk outdoors. Twenty healthy participants performed a three-class auditory oddball task, which included rare target and non-target distractor stimuli presented with equal probabilities of 16%. Data were recorded in a seated (control condition) and in a walking condition, both of which were realized outdoors. A significantly larger P300 event-related potential amplitude was evident for targets compared to distractors (p<.001), but no significant interaction with recording condition emerged. P300 single-trial analysis was performed with regularized stepwise linear discriminant analysis and revealed above chance-level classification accuracies for most participants (19 out of 20 for the seated, 16 out of 20 for the walking condition), with mean classification accuracies of 71% (seated) and 64% (walking). Moreover, the resulting information transfer rates for the seated and walking conditions were comparable to a recently published laboratory auditory brain-computer interface (BCI) study. This leads us to conclude that a truly mobile auditory BCI system is feasible.
authors.affiliation: Neuropsychology Lab, Department of Psychology, University of Oldenburg, Germany; Research Center Neurosensory Science, University of Oldenburg, Germany; Cluster of Excellence Hearing4all, University of Oldenburg, Germany. Electronic address: Maarten.de.vos@uni-oldenburg.de.
authors.forename: Maarten
authors.initials: M
authors.lastname: De Vos
authors.affiliation: Neuropsychology Lab, Department of Psychology, University of Oldenburg, Germany.
authors.forename: Katharina
authors.initials: K
authors.lastname: Gandras
authors.affiliation: Neuropsychology Lab, Department of Psychology, University of Oldenburg, Germany; Research Center Neurosensory Science, University of Oldenburg, Germany; Cluster of Excellence Hearing4all, University of Oldenburg, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Debener
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D000704:Analysis of Variance; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D062207:Brain-Computer Interfaces; D018913:Event-Related Potentials, P300 / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D063731:Mobile Applications; D025341:Principal Component Analysis; D012146:Rest / Q000502:physiology; D016138:Walking / Q000502:physiology; D055815:Young Adult
keywords: Brain–computer interface; Mobile EEG; P300; Single-trial analysis