Dreyer Alexander M, Heikkinen Benjamin L A, Herrmann Christoph S
Applied Neurocognitive Psychology Lab, Department of Psychology, European Medical School, Carl von Ossietzky University, Oldenburg, Germany.
Experimental Psychology Lab, Department of Psychology, European Medical School, Cluster for Excellence "Hearing for All", Carl von Ossietzky University, Oldenburg, Germany.
Front Hum Neurosci. 2022 Mar 10;16:859519. doi: 10.3389/fnhum.2022.859519. eCollection 2022.
Based on increased user experience during stimulation, frequency-modulated steady-state visual evoked potentials (FM-SSVEPs) have been suggested as an improved stimulation method for brain-computer interfaces. Adapting such a novel stimulation paradigm requires in-depth analyses of all different stimulation parameters and their influence on brain responses as well as the user experience during the stimulation. In the current manuscript, we assess the influence of different values for the modulation index, which determine the spectral distribution in the stimulation signal on FM-SSVEPs. We visually stimulated 14 participants at different target frequencies with four different values for the modulation index. Our results reveal that changing the modulation index in a way that elevates the stimulation power in the targeted sideband leads to increased FM-SSVEP responses. There is, however, a tradeoff with user experience as increased modulation indices also lead to increased perceived flicker intensity as well as decreased stimulation comfort in our participants. Our results can guide the choice of parameters in future FM-SSVEP implementations.
基于刺激过程中增强的用户体验，调频稳态视觉诱发电位（FM - SSVEPs）已被提议作为脑机接口的一种改进刺激方法。采用这种新型刺激范式需要深入分析所有不同的刺激参数及其对大脑反应的影响，以及刺激过程中的用户体验。在当前的手稿中，我们评估了调制指数的不同值对FM - SSVEPs的影响，调制指数决定了刺激信号中的频谱分布。我们用四种不同的调制指数值，在不同的目标频率下对14名参与者进行视觉刺激。我们的结果表明，以提高目标边带中刺激功率的方式改变调制指数会导致FM - SSVEP反应增强。然而，这与用户体验存在权衡，因为调制指数的增加也会导致我们的参与者感觉到的闪烁强度增加以及刺激舒适度降低。我们的结果可以为未来FM - SSVEP实施中的参数选择提供指导。
