A high-performance brain switch based on code-modulated visual evoked potentials

Li Zheng; Weihua Pei; Xiaorong Gao; Lijian Zhang; Yijun Wang

doi:10.1088/1741-2552/ac494f

A high-performance brain switch based on code-modulated visual evoked potentials

J Neural Eng. 2022 Jan 24;19(1). doi: 10.1088/1741-2552/ac494f.

Authors

Li Zheng^{1

2}, Weihua Pei^{1

2}, Xiaorong Gao³, Lijian Zhang⁴, Yijun Wang^{1

2}

Affiliations

¹ State Key Laboratory on Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, People's Republic of China.
² School of Future Technology, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China.
³ Department of Biomedical Engineering, Tsinghua University, Beijing 100084, People's Republic of China.
⁴ Beijing Machine and Equipment Institute, Beijing 100854, People's Republic of China.

PMID: 34996051
DOI: 10.1088/1741-2552/ac494f

Abstract

Objective.Asynchronous brain-computer interfaces (BCIs) are more practical and natural compared to synchronous BCIs. A brain switch is a standard asynchronous BCI, which can automatically detect the specified change of the brain and discriminate between the control state and the idle state. The current brain switches still face challenges on relatively long reaction time (RT) and high false positive rate (FPR).Approach.In this paper, an online electroencephalography-based brain switch is designed to realize a fast reaction and keep long idle time (IDLE) without false positives (FPs) using code-modulated visual evoked potentials (c-VEPs). Two stimulation paradigms were designed and compared in the experiments: multi-code concatenate modulation (concatenation mode) and single-code periodic modulation (periodic mode). Using a task-related component analysis-based detection algorithm, EEG data can be decoded into a series of code indices. Brain states can be detected by a template matching approach with a sliding window on the output series.Main results.The online experiments achieved an averageRTof 1.49 s when the averageIDLEfor eachFPwas 68.57 min (1.46 × 10^-2FP min^-1) or an averageRTof 1.67 s withoutFPs. Significance.This study provides a practical c-VEP based brain switch system with both fast reaction and low FPR during idle state, which can be used in various BCI applications.

Keywords: asynchronous brain-computer interface; brain switch; code-modulated visual evoked potential.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Algorithms
Brain / physiology
Brain-Computer Interfaces*
Electroencephalography / methods
Evoked Potentials
Evoked Potentials, Visual*
Photic Stimulation