Authors:
Jan Ehlers
1
;
Thorsten Lueth
2
and
Axel Graeser
2
Affiliations:
1
Institute of Media Informatics, Bauhaus University Weimar, Bauhausstr 11, 99423 Weimar and Germany
;
2
Institute of Automation, University of Bremen, Otto-Hahn-Alle 1, 28359 Bremen and Germany
Keyword(s):
Brain-Computer Interfaces, SSVEP, EEG.
Related
Ontology
Subjects/Areas/Topics:
Biomedical Engineering
;
Biomedical Instruments and Devices
;
Brain-Computer Interfaces
;
Devices
;
Human-Computer Interaction
;
Physiological Computing Systems
Abstract:
Steady-State Visual Evoked Potentials (SSVEP) constitute an established approach to operate a Brain-Computer Interface (BCI). In contrast to stimulation between 13 and 17 Hz, stimulation above 30 Hz is considered less annoying and diminishes the risk of epileptic seizures. However, high-frequency BCIs usually feature slow processing speed and accuracy rates which reduces user satisfaction. We investigate the re-test stability of resonance frequencies between 30 and 50 Hz in 18 participants over a period of 40 days, including seven consecutive runs. Aim is to determine individual resonance profiles for recurring BCI usage that make time-consuming calibration phases no longer necessary. Preliminary findings of a clinical sample are reported as well. Results indicate that seven of nine frequencies fail to repeatedly induce stable responses. However, stimulation with 32 and 40 Hz induced strong and recurring SSVEP in the vast majorities of trials. Consequently, high-frequency based BCI u
sage will continue to presuppose individual calibration. Apart from this, since 40 Hz oscillations are suggested to play a key role in various brain functions, it is reasonable to assume pronounced cortical reactions to 32 Hz to also constitute a neuronal oscillator that is functional active during cognitive processing.
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