摘要
因 P300 脑-机接口系统的准确率和信息传输率较高,已被广泛应用。研究表明,视觉刺激的强度会影响脑-机接口系统的性能,本文对此展开了相关范式研究。首先,按人眼感知灰度的敏锐度将视觉刺激强度划分为9种灰度值并设计刺激范式;然后,通过实验采集9种灰度值刺激源诱发的 P300 电位数据;最后,对数据进行分析,得到灰度值与 P300 电位强度和电位分类准确率的关系信息。实验结果表明,振幅、潜伏期与灰度值之间存在一种波动增长关系,同样,灰度值与电位分类准确率也呈现此种关系,为 P300 脑-机接口系统的刺激源设计提供了重要依据。
P300-based brain-computer interface (BCI) has been widely applied due to its high accuracy and information transfer rate (ITR). Previous research showed that the intensity of visual stimuli would affect the performance of brain-computer interface systems. In this paper, we proposed a novel configuration of visual stimulus on grey value. Firstly, the RGB full range (from 0 to 255) was divided into 9 levels according to the grey-scale sensitivity of the human eye. This is for exploring the intrinsic effects brought by the grey value about the amplitude and response time (RT) of P300 wave, and the accuracy and ITR of the BCI system. In this new paradigm, 9 kinds of stimuli were displayed in the assigned squares distributed on the black (255, 255, 255) background. During this process, the stimulus was presented with random grey values in target squares or in non-target ones, which required every subject to focus his/her mind on every target flicker in the target square in spite of the differences in grey values. 18 healthy subjects were invited to do the experiment where 16 channels were utilized. It was found that the increasing in grey value produced fluctuation increasing in amplitude, accuracy and ITR, while the increasing in grey value resulted in decreasing in RT with fluctuations. Moreover, the grey value 2 showed the highest averaged offline accuracy, ITR and amplitude of P300, while the grey value 3 performed the highest averaged online accuracy and ITR. These results provided evidence for stimulus design and grey value selection.
作者
郭妙吉
金晶
王行愚
GUO Miaoji;JIN Jing;WANG Xingyu(Key Laboratory of Advanced Control and Optimization for Chemical Processes,Ministry of Education,School ofInformation Science and Engineexing,East China University of Science and Technology,Shanghai 200237,China)
出处
《华东理工大学学报（自然科学版）》
CAS
CSCD
北大核心
2019年第3期458-465,共8页
Journal of East China University of Science and Technology
基金
国家自然科学基金(91420302,61573142)
国家重点研发计划(2017YFB13003002)
111引智计划(B17017)
关键词
脑-机接口
灰度值
闪光刺激
P300
brain-computer interface
grey value
flash stimulation
P300
