A SSVEP-BCI setup based on Depth-of-Field

Anibal Cotrina, Alessandro Botti Benevides, Javier Castillo-Garcia, Alessander Botti Benevides, David Rojas-Vigo, Andre Ferreira, Teodiano Freire Bastos-Filho

    Research output: Contribution to journalArticleResearchpeer-review

    10 Citations (Scopus)


    © 2001-2011 IEEE. In optical systems, the range of distance near the point of focus where objects are perceived sharply is referred as depth-of-field; objects outside this region are defocused and blurred. Furthermore, ophthalmology studies state that the amplitude and the latency of visual evoked potentials are affected by defocusing. In this context, this paper evaluates a novel setup for a steady-state visual evoked potential (SSVEP) brain-computer interface, in which two stimuli are presented together in the center of the user's field of view but at different distances ensuring that if one stimulus is focused on, the other one is non-focused, and vice versa. The evaluationwas conductedwith eight healthy subjects who were asked to focus on just one stimulus at a time. An average accuracy rate of 0.93 was achieved for a time window of 4 s by employing well know SSVEP detection methods. Results show that distinguishable SSVEP can be elicited by the focused stimulus regardless of the non-focused one is also present in the field of view. Finally, this approach allows users to send commands through a stimuli selection by focusing mechanism that does not demand neck, head, and/or eyeball movements.
    Original languageEnglish
    Article number7862911
    Pages (from-to)1047-1057
    JournalIEEE Transactions on Neural Systems and Rehabilitation Engineering
    Issue number7
    Publication statusPublished - 1 Jul 2017


    • Electroencephalogram
    • biomedical signal processing
    • brain-computer interface
    • human-computer interaction


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