Stimulator Selection in SSVEP-Based Spatial Selective Attention Study.

Songyun Xie,Chang Liu,Fangshi Zhu,Linan Wang,Xinzhou Xie,Klaus Obermayer,Wei Wang

doi:10.1155/2016/6410718

Abstract

Steady-State Visual Evoked Potentials (SSVEPs) are widely used in spatial selective attention. In this process the two kinds of visual simulators, Light Emitting Diode (LED) and Liquid Crystal Display (LCD), are commonly used to evoke SSVEP. In this paper, the differences of SSVEP caused by these two stimulators in the study of spatial selective attention were investigated. Results indicated that LED could stimulate strong SSVEP component on occipital lobe, and the frequency of evoked SSVEP had high precision and wide range as compared to LCD. Moreover a significant difference between noticed and unnoticed frequencies in spectrum was observed whereas in LCD mode this difference was limited and selectable frequencies were also limited. Our experimental finding suggested that average classification accuracies among all the test subjects in our experiments were 0.938 and 0.853 in LED and LCD mode, respectively. These results indicate that LED simulator is appropriate for evoking the SSVEP for the study of spatial selective attention.

Highlights

Attention is the cognitive process of selectively concentrating on one area while ignoring others [1]
The comparisons were carried out in the analysis of spectrum as well as the accuracy of classification based on two classical paradigms of spatial selective attention proposed by Morgan et al [1] and Muller et al [21] with slight changes, like the stimulating frequencies being changed to 8 Hz and 12 Hz in both Liquid Crystal Display (LCD) and Light Emitting Diode (LED) condition for the contradistinctive reason
Strong State Visual Evoked Potential (SSVEP) had already been induced by LED, which was consistent with previous researches [13, 22, 26, 27]

Summary

Introduction

Attention is the cognitive process of selectively concentrating on one area while ignoring others [1]. Visual evoked potential provides a flexible way to study the visual cognitive process [2,3,4]. The Steady-State Visual Evoked Potential (SSVEP) is the response of the brain to a stimulus flickering at a constant frequency [4, 5]. The amplitude of SSVEP is enhanced when subjects’ attention is cued to the stimulus. This contralateral distribution of the oscillation and the amplitude difference are efficient features to investigate visual spatial selective attention [12], and this selective feature has been applied in several researches as a measurement method such as the study of the binocular rivalry by Zhang et al [13] and Wang et al [14]

Results

Discussion

Conclusion