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Use of a Green Familiar Faces Paradigm Improves P300-Speller Brain-Computer Interface Performance.

Li Q, Liu S, Li J, Bai O - PLoS ONE (2015)

Bottom Line: We analyzed the ERP waveforms elicited by the FF and proposed GFF spelling paradigms and compared P300-speller performance between the two paradigms.Compared to the FF spelling paradigm, the GFF spelling paradigm elicited ERP waveforms of higher amplitudes and resulted in improved P300-speller performance.These findings demonstrate a promising new approach for improving the performance of the P300-speller.

View Article: PubMed Central - PubMed

Affiliation: School of Computer Science and Technology, Changchun University of Science and Technology, Changchun, China.

ABSTRACT

Background: A recent study showed improved performance of the P300-speller when the flashing row or column was overlaid with translucent pictures of familiar faces (FF spelling paradigm). However, the performance of the P300-speller is not yet satisfactory due to its low classification accuracy and information transfer rate.

Objective: To investigate whether P300-speller performance is further improved when the chromatic property and the FF spelling paradigm are combined.

Methods: We proposed a new spelling paradigm in which the flashing row or column is overlaid with translucent green pictures of familiar faces (GFF spelling paradigm). We analyzed the ERP waveforms elicited by the FF and proposed GFF spelling paradigms and compared P300-speller performance between the two paradigms.

Results: Significant differences in the amplitudes of four ERP components (N170, VPP, P300, and P600f) were observed between both spelling paradigms. Compared to the FF spelling paradigm, the GFF spelling paradigm elicited ERP waveforms of higher amplitudes and resulted in improved P300-speller performance.

Conclusions: Combining the chromatic property (green color) and the FF spelling paradigm led to better classification accuracy and an increased information transfer rate. These findings demonstrate a promising new approach for improving the performance of the P300-speller.

No MeSH data available.


Related in: MedlinePlus

Experimental arrangement of each spelling paradigm in the offline (a) and online (b) experiments.
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pone.0130325.g002: Experimental arrangement of each spelling paradigm in the offline (a) and online (b) experiments.

Mentions: Each subject sat in a comfortable chair approximately 70 cm from the front of the computer monitor. Subjects were asked to focus on the target character, avoid blinking during stimulus presentation, and silently count the number of target character flashes. In the offline experiment, each spelling paradigm was conducted six times with different five-character words, and each was considered a separate session. Each session consisted of five runs, each of which involved a different target character. One flash of a row or column was referred to as a trial. The flash of a row or column including the target character was defined as a target trial, and the flash of a row or column without the target character was defined as a non-target trial. A sequence consisted of 12 flashes (trails), six from the rows and six from the columns. In each run, the sequence was repeated 15 times (Fig 2a). Thus, each run consisted of 180 flashes of row or column to output a target character. Participants never received feedback. The sessions of the two paradigms were conducted alternately to control for potential habituation effects. Participants were allowed to take a 5-min break between sessions. To avoid novelty effects, the stimulus image in each spelling paradigm was presented to subjects for 20 s prior to each session.


Use of a Green Familiar Faces Paradigm Improves P300-Speller Brain-Computer Interface Performance.

Li Q, Liu S, Li J, Bai O - PLoS ONE (2015)

Experimental arrangement of each spelling paradigm in the offline (a) and online (b) experiments.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4472698&req=5

pone.0130325.g002: Experimental arrangement of each spelling paradigm in the offline (a) and online (b) experiments.
Mentions: Each subject sat in a comfortable chair approximately 70 cm from the front of the computer monitor. Subjects were asked to focus on the target character, avoid blinking during stimulus presentation, and silently count the number of target character flashes. In the offline experiment, each spelling paradigm was conducted six times with different five-character words, and each was considered a separate session. Each session consisted of five runs, each of which involved a different target character. One flash of a row or column was referred to as a trial. The flash of a row or column including the target character was defined as a target trial, and the flash of a row or column without the target character was defined as a non-target trial. A sequence consisted of 12 flashes (trails), six from the rows and six from the columns. In each run, the sequence was repeated 15 times (Fig 2a). Thus, each run consisted of 180 flashes of row or column to output a target character. Participants never received feedback. The sessions of the two paradigms were conducted alternately to control for potential habituation effects. Participants were allowed to take a 5-min break between sessions. To avoid novelty effects, the stimulus image in each spelling paradigm was presented to subjects for 20 s prior to each session.

Bottom Line: We analyzed the ERP waveforms elicited by the FF and proposed GFF spelling paradigms and compared P300-speller performance between the two paradigms.Compared to the FF spelling paradigm, the GFF spelling paradigm elicited ERP waveforms of higher amplitudes and resulted in improved P300-speller performance.These findings demonstrate a promising new approach for improving the performance of the P300-speller.

View Article: PubMed Central - PubMed

Affiliation: School of Computer Science and Technology, Changchun University of Science and Technology, Changchun, China.

ABSTRACT

Background: A recent study showed improved performance of the P300-speller when the flashing row or column was overlaid with translucent pictures of familiar faces (FF spelling paradigm). However, the performance of the P300-speller is not yet satisfactory due to its low classification accuracy and information transfer rate.

Objective: To investigate whether P300-speller performance is further improved when the chromatic property and the FF spelling paradigm are combined.

Methods: We proposed a new spelling paradigm in which the flashing row or column is overlaid with translucent green pictures of familiar faces (GFF spelling paradigm). We analyzed the ERP waveforms elicited by the FF and proposed GFF spelling paradigms and compared P300-speller performance between the two paradigms.

Results: Significant differences in the amplitudes of four ERP components (N170, VPP, P300, and P600f) were observed between both spelling paradigms. Compared to the FF spelling paradigm, the GFF spelling paradigm elicited ERP waveforms of higher amplitudes and resulted in improved P300-speller performance.

Conclusions: Combining the chromatic property (green color) and the FF spelling paradigm led to better classification accuracy and an increased information transfer rate. These findings demonstrate a promising new approach for improving the performance of the P300-speller.

No MeSH data available.


Related in: MedlinePlus