Brain oscillations are vital to cognitive functions, while disrupted oscillatory activity is linked to various brain disorders. Although high-frequency neural oscillations (> 1 Hz) have been extensively studied in cognition, the neural mechanisms underlying low-frequency hemodynamic oscillations (LFHO) < 1 Hz have not yet been fully explored. One way to examine oscillatory neural dynamics is to use a facial expression (FE) paradigm to induce steady-state visual evoked potentials (SSVEPs), which has been used in electroencephalography studies of high-frequency brain oscillation activity. In this study, LFHO during SSVEP-inducing periodic flickering stimuli presentation were inspected using functional near-infrared spectroscopy (fNIRS), in which hemodynamic responses in the prefrontal cortex were recorded while participants were passively viewing dynamic FEs flickering at 0.2 Hz. The fast Fourier analysis results demonstrated that the power exhibited monochronic peaks at 0.2 Hz across all channels, indicating that the periodic events successfully elicited LFHO in the prefrontal cortex. More importantly, measurement of LFHO can effectively distinguish the brain activation difference between different cognitive conditions, with happy FE presentation showing greater LFHO power than neutral FE presentation. These results demonstrate that stimuli flashing at a given frequency can induce LFHO in the prefrontal cortex, which provides new insights into the cognitive mechanisms involved in slow oscillation.

中文翻译：

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功能性近红外光谱可以在稳态视觉诱发电位诱导周期性面部表情刺激表现期间检测前额叶皮层中的低频血液动力学振荡

脑震荡对认知功能至关重要，而震荡活动中断与各种脑部疾病有关。尽管在认知方面已对高频神经振荡（> 1 Hz）进行了广泛研究，但尚未充分探究低频血液动力学振荡（LFHO）<1 Hz的神经机制。检查振荡神经动力学的一种方法是使用面部表情（FE）范式来诱发稳态视觉诱发电位（SSVEP），该方法已用于高频脑震荡活动的脑电图研究。在这项研究中，使用功能近红外光谱（fNIRS）检查了在SSVEP诱导周期性闪烁刺激表现期间的LFHO，其中记录了前额叶皮层的血流动力学响应，而参与者则被动地观察到动态FE在0.2 Hz处闪烁。快速傅立叶分析结果表明，该功率在所有通道上均显示0.2 Hz的单时峰，表明周期性事件成功地在前额叶皮层诱发了LFHO。更重要的是，LFHO的测量可以有效地区分不同认知条件之间的大脑激活差异，快乐的FE表现比中性FE表现出更大的LFHO功能。这些结果表明，以给定的频率闪烁可以在前额叶皮层中诱导LFHO，这为参与慢振荡的认知机制提供了新的见识。快速傅立叶分析结果表明，该功率在所有通道上均显示0.2 Hz的单时峰，表明周期性事件成功地在前额叶皮层诱发了LFHO。更重要的是，LFHO的测量可以有效地区分不同认知条件之间的大脑激活差异，快乐的FE表现比中性FE表现出更大的LFHO功能。这些结果表明，以给定的频率闪烁可以在前额叶皮层中诱导LFHO，这为参与慢振荡的认知机制提供了新的见识。快速傅立叶分析结果表明，该功率在所有通道上均显示0.2 Hz的单时峰，表明周期性事件成功地在前额叶皮层诱发了LFHO。更重要的是，LFHO的测量可以有效地区分不同认知条件之间的大脑激活差异，快乐的FE表现比中性FE表现出更大的LFHO功能。这些结果表明，以给定的频率闪烁可以在前额叶皮层中诱导LFHO，这为参与慢振荡的认知机制提供了新的见识。测量LFHO可以有效地区分不同认知条件之间的大脑激活差异，快乐的FE表现比中性FE表现出更大的LFHO功能。这些结果表明，以给定的频率闪烁可以在前额叶皮层中诱导LFHO，这为参与慢振荡的认知机制提供了新的见识。测量LFHO可以有效地区分不同认知条件之间的大脑激活差异，快乐的FE表现比中性FE表现出更大的LFHO功能。这些结果表明，以给定的频率闪烁可以在前额叶皮层中诱导LFHO，这为参与慢振荡的认知机制提供了新的见识。