Gu Meng, Pei Weihua, Gao Xiaorong, Wang Yijun
Key Laboratory of Solid-State Optoelectronics Information Technology, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, People's Republic of China.
College of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing, People's Republic of China.
J Neural Eng. 2025 Jan 23;22(1). doi: 10.1088/1741-2552/adaa1e.
Steady-state visual evoked potentials (SSVEPs) rely on the photic driving response to encode electroencephalogram (EEG) signals stably and efficiently. However, the user experience of the traditional stimulation with high-contrast flickers urgently needs to be improved. In this study, we introduce a novel paradigm of grid stimulation with weak flickering perception, distinguished by a markedly lower proportion of stimulation area in the overall pattern.In an offline single-target experiment, we investigated the unique characteristics of SSVEPs evoked by varying proportions in grid stimuli within low and medium frequency bands. Based on the analysis of simulation performance across a four-class brain-computer interface (BCI) task and the evaluation of user experience questionnaires, a subset of paradigms that balance performance and comfort were selected for implementation in four-target online BCI systems.Our results demonstrate that even ultra-low stimulation proportion paradigms can still evoke strong responses within specific frequency bands, effectively enhancing user experience with low and middle frequency stimuli. Notably, proportions of 0.94% and 2.10% within the 3-5 Hz range provide an optimal balance between performance and user experience. For frequencies extending up to 15 Hz, a 2.10% proportion remains ideal. At 20 Hz, slightly higher proportions of 3.75% and 8.43% maintain these benefits.These findings are crucial for advancing the development of effective and user-friendly SSVEP-based BCI systems.
稳态视觉诱发电位（SSVEPs）依靠光驱动响应来稳定、高效地编码脑电图（EEG）信号。然而，传统的高对比度闪烁刺激的用户体验亟待改善。在本研究中，我们引入了一种具有微弱闪烁感知的新型网格刺激范式，其特点是在整体模式中刺激区域的比例明显更低。在离线单目标实验中，我们研究了低频和中频带内不同比例网格刺激诱发的SSVEPs的独特特征。基于对四类脑机接口（BCI）任务的模拟性能分析和用户体验问卷评估，选择了一组平衡性能和舒适度的范式在四目标在线BCI系统中实施。我们的结果表明，即使是超低刺激比例范式在特定频段内仍能诱发强烈反应，有效提升了低频和中频刺激的用户体验。值得注意的是，在3 - 5Hz范围内，0.94%和2.10%的比例在性能和用户体验之间提供了最佳平衡。对于高达15Hz的频率，2.10%的比例仍然是理想的。在20Hz时，略高的3.75%和8.43%的比例保持了这些优势。这些发现对于推进基于SSVEP的有效且用户友好的BCI系统的发展至关重要。
