Title
Hybrid frequency and phase coding for a high-speed SSVEP-based BCI speller.
Abstract
Steady-state visual evoked potential (SSVEP)-based brain-computer interfaces (BCIs) have potential to realize high-speed communication between the human brain and the external environment. Recently, multiple access (MA) methods in telecommunications have been introduced into the system design of BCIs and showed their potential in improving BCI performance. This study investigated the feasibility of hybrid frequency and phase coding methods in multi-target SSVEP-based BCIs. Specifically, this study compared two hybrid target-coding strategies: (1) mixed frequency and phase coding, and (2) joint frequency and phase coding. In a simulated online BCI experiment using a 40-target BCI speller, BCI performance for both coding approaches were tested with a group of six subjects. At a spelling speed of 40 characters per minute (1.5 seconds per character), both approaches obtained high information transfer rates (ITR) (mixed coding: 172.37±28.67 bits/min, joint coding: 170.94±28.32 bits/min) across subjects. There was no statistically significant difference between the two approaches (p>0.05). These results suggest that the hybrid frequency and phase coding methods are highly efficient for multi-target coding in SSVEP BCIs with a large number of classes, providing a practical solution to implement a high-speed BCI speller.
Year
DOI
Venue
2014
10.1109/EMBC.2014.6944499
EMBC
Keywords
Field
DocType
online bci experiment,high-speed bci speller,steady-state visual evoked potential,high-speed ssvep-based bci speller,brain-computer interfaces,visual evoked potentials,frequency coding methods,hybrid target-coding strategy,phase coding methods,phase coding
Computer vision,Computer science,Brain–computer interface,Speech recognition,Phase coding,Artificial intelligence
Conference
Volume
ISSN
Citations 
2014
1557-170X
0
PageRank 
References 
Authors
0.34
0
5
Name
Order
Citations
PageRank
Xiaogang Chen111.09
Yijun Wang230846.68
Masaki Nakanishi331.39
Tzyy-Ping Jung414423.93
Xiaorong Gao500.34