刺激视野面积对稳态视觉诱发电位的影响

基于稳态视觉诱发电位（SSVEP）的脑-机接口（BCI）系统通常采用占据较大视野面积的闪烁刺激以诱发更明显的脑电特征，但容易造成使用者疲劳、紧张和头痛，限制了SSVEP-BCI的实际应用。针对此问题，该文以幅值、信噪比、典型相关系数和任务相关系数为指标，探究了不同刺激视野面积（以角度尺寸进行衡量，范围为0.1°至13°）对诱发SSVEP信号特征强度的影响。分析结果表明，SSVEP信号的强度最初随刺激角度尺寸的增大而增大，但在角度尺寸达到3°左右后增长开始变缓并保持平稳。综合考虑系统舒适度和特征强度两个因素后得出结论，SSVEP-BCI系统的刺激角度尺寸约为3°时能够达到最佳性能。该文为SSVEP-BCI的最佳刺激角度尺寸选择提供了依据，相关研究成果在舒适友好型BCI方面具有潜在的应用价值。

Research on the Effect of Stimulus Areas on Steady-State Visual Evoked Potential

? ?Brain-computer interface （BCI） systems based on steady-state visual evoked potential （SSVEP） preferred to use large-size stimuli to induce stronger electroencephalography（EEG） features， but the utilization of this kind of stimuli was likely to cause users unpreferred symptoms like fatigue， tension， or headache. These side effects limited the practical application of SSVEP-BCI. To solve this problem， the present study aimed at the influence of different stimulus areas（measured by angle sizes， ranging from 0.1° to 13°） on the SSVEPs with amplitude， signal-to-noise ratio， canonical correlation coefficient， and task-related coefficient as indicators. The results demonstrated that the SSVEPs initially enlarged as the angle sizes increase before reaching 3° and kept flat after that. It is concluded that the SSVEP-BCI can achieve the best performance when the angle sizes of stimuli are about 3°， considering system comfort and signal strength. This study provides a promising approach for optimizing the angle sizes of stimuli for SSVEP-BCI， which is significant in BCI development.