Eliciting dual-frequency SSVEP using a hybrid SSVEP-P300 BCI

Min Hye Chang, Jeong Su Lee, Jeong Heo, Kwangsuk Park

Research output: Contribution to journalArticleResearchpeer-review

26 Citations (Scopus)

Abstract

Background: Steady-state visual-evoked potential (SSVEP)-based brain-computer interfaces (BCIs) generate weak SSVEP with a monitor and cannot use harmonic frequencies, whereas P300-based BCIs need multiple stimulation sequences. These issues can decrease the information transfer rate (ITR). New method: In this paper, we introduce a novel hybrid SSVEP-P300 speller that generates dual-frequency SSVEP, allowing it to overcome the abovementioned limitations and improve the performance. The hybrid speller consists of nine panels flickering at different frequencies. Each panel contains four different characters that appear in a random sequence. The flickering panel and the periodically updating character evoke the dual-frequency SSVEP, while the oddball stimulus of the target character evokes the P300. A canonical correlation analysis (CCA) and a step-wise linear discriminant analysis (SWLDA) classified SSVEP and P300, respectively. Ten subjects participated in offline and online experiments, in which accuracy and ITR were compared with those of conventional SSVEP and P300 spellers. Results: The offline analysis revealed not only the P300 potential but also SSVEP with peaks at sub-harmonic frequencies, demonstrating that the proposed speller elicited dual-frequency SSVEP. This dual-frequency stimulation improved SSVEP recognition, increased the number of targets by employing harmonic frequencies, reduced the stimulation time for P300, and consequently improved ITR as compared to the conventional spellers. Comparison with existing methods: The new method reduces the stimulation time and allows harmonic frequencies to be employed for different stimuli. Conclusions: The results indicate that this study provides a promising approach to make the BCI speller more reliable and efficient.

Original languageEnglish
Pages (from-to)104-113
Number of pages10
JournalJournal of Neuroscience Methods
Volume258
DOIs
StatePublished - 30 Jan 2016

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Brain-Computer Interfaces
Visual Evoked Potentials
Discriminant Analysis

Keywords

  • BCI speller
  • Brain-computer interface (BCI)
  • Dual frequency
  • Hybrid BCI
  • P300
  • Steady-state visual-evoked potential (SSVEP)

Cite this

Chang, Min Hye ; Lee, Jeong Su ; Heo, Jeong ; Park, Kwangsuk. / Eliciting dual-frequency SSVEP using a hybrid SSVEP-P300 BCI. In: Journal of Neuroscience Methods. 2016 ; Vol. 258. pp. 104-113.
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abstract = "Background: Steady-state visual-evoked potential (SSVEP)-based brain-computer interfaces (BCIs) generate weak SSVEP with a monitor and cannot use harmonic frequencies, whereas P300-based BCIs need multiple stimulation sequences. These issues can decrease the information transfer rate (ITR). New method: In this paper, we introduce a novel hybrid SSVEP-P300 speller that generates dual-frequency SSVEP, allowing it to overcome the abovementioned limitations and improve the performance. The hybrid speller consists of nine panels flickering at different frequencies. Each panel contains four different characters that appear in a random sequence. The flickering panel and the periodically updating character evoke the dual-frequency SSVEP, while the oddball stimulus of the target character evokes the P300. A canonical correlation analysis (CCA) and a step-wise linear discriminant analysis (SWLDA) classified SSVEP and P300, respectively. Ten subjects participated in offline and online experiments, in which accuracy and ITR were compared with those of conventional SSVEP and P300 spellers. Results: The offline analysis revealed not only the P300 potential but also SSVEP with peaks at sub-harmonic frequencies, demonstrating that the proposed speller elicited dual-frequency SSVEP. This dual-frequency stimulation improved SSVEP recognition, increased the number of targets by employing harmonic frequencies, reduced the stimulation time for P300, and consequently improved ITR as compared to the conventional spellers. Comparison with existing methods: The new method reduces the stimulation time and allows harmonic frequencies to be employed for different stimuli. Conclusions: The results indicate that this study provides a promising approach to make the BCI speller more reliable and efficient.",
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Eliciting dual-frequency SSVEP using a hybrid SSVEP-P300 BCI. / Chang, Min Hye; Lee, Jeong Su; Heo, Jeong; Park, Kwangsuk.

In: Journal of Neuroscience Methods, Vol. 258, 30.01.2016, p. 104-113.

Research output: Contribution to journalArticleResearchpeer-review

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T1 - Eliciting dual-frequency SSVEP using a hybrid SSVEP-P300 BCI

AU - Chang, Min Hye

AU - Lee, Jeong Su

AU - Heo, Jeong

AU - Park, Kwangsuk

PY - 2016/1/30

Y1 - 2016/1/30

N2 - Background: Steady-state visual-evoked potential (SSVEP)-based brain-computer interfaces (BCIs) generate weak SSVEP with a monitor and cannot use harmonic frequencies, whereas P300-based BCIs need multiple stimulation sequences. These issues can decrease the information transfer rate (ITR). New method: In this paper, we introduce a novel hybrid SSVEP-P300 speller that generates dual-frequency SSVEP, allowing it to overcome the abovementioned limitations and improve the performance. The hybrid speller consists of nine panels flickering at different frequencies. Each panel contains four different characters that appear in a random sequence. The flickering panel and the periodically updating character evoke the dual-frequency SSVEP, while the oddball stimulus of the target character evokes the P300. A canonical correlation analysis (CCA) and a step-wise linear discriminant analysis (SWLDA) classified SSVEP and P300, respectively. Ten subjects participated in offline and online experiments, in which accuracy and ITR were compared with those of conventional SSVEP and P300 spellers. Results: The offline analysis revealed not only the P300 potential but also SSVEP with peaks at sub-harmonic frequencies, demonstrating that the proposed speller elicited dual-frequency SSVEP. This dual-frequency stimulation improved SSVEP recognition, increased the number of targets by employing harmonic frequencies, reduced the stimulation time for P300, and consequently improved ITR as compared to the conventional spellers. Comparison with existing methods: The new method reduces the stimulation time and allows harmonic frequencies to be employed for different stimuli. Conclusions: The results indicate that this study provides a promising approach to make the BCI speller more reliable and efficient.

AB - Background: Steady-state visual-evoked potential (SSVEP)-based brain-computer interfaces (BCIs) generate weak SSVEP with a monitor and cannot use harmonic frequencies, whereas P300-based BCIs need multiple stimulation sequences. These issues can decrease the information transfer rate (ITR). New method: In this paper, we introduce a novel hybrid SSVEP-P300 speller that generates dual-frequency SSVEP, allowing it to overcome the abovementioned limitations and improve the performance. The hybrid speller consists of nine panels flickering at different frequencies. Each panel contains four different characters that appear in a random sequence. The flickering panel and the periodically updating character evoke the dual-frequency SSVEP, while the oddball stimulus of the target character evokes the P300. A canonical correlation analysis (CCA) and a step-wise linear discriminant analysis (SWLDA) classified SSVEP and P300, respectively. Ten subjects participated in offline and online experiments, in which accuracy and ITR were compared with those of conventional SSVEP and P300 spellers. Results: The offline analysis revealed not only the P300 potential but also SSVEP with peaks at sub-harmonic frequencies, demonstrating that the proposed speller elicited dual-frequency SSVEP. This dual-frequency stimulation improved SSVEP recognition, increased the number of targets by employing harmonic frequencies, reduced the stimulation time for P300, and consequently improved ITR as compared to the conventional spellers. Comparison with existing methods: The new method reduces the stimulation time and allows harmonic frequencies to be employed for different stimuli. Conclusions: The results indicate that this study provides a promising approach to make the BCI speller more reliable and efficient.

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KW - Hybrid BCI

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KW - Steady-state visual-evoked potential (SSVEP)

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JO - Journal of Neuroscience Methods

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