Thomas C G, Menon R S
Department of Medical Biophysics, University of Western Ontario, London, Canada.
Magn Reson Med. 1998 Aug;40(2):203-9. doi: 10.1002/mrm.1910400206.
Detailed measurement of the neural response to flicker frequency using functional MRI (fMRI) were made. The fMRI signal peaks at a flicker frequency of 8 Hz in human V1, in agreement with previous positron emission tomography (PET) and fMRI experiments. The modulation amplitude of the hemodynamic response to varying continuous periods of flicker stimulation was measured. The hemodynamic response was not observed to be modulated by neural modulation for periods shorter than 6.7 s. The resemblance between the BOLD response to the stimulus presentation frequency and the base-line power spectra at the same frequencies suggests that the same underlying mechanism could be responsible for both curves and that the base-line fMRI power spectrum is probably due to base-line electrical activity in the brain. The integrals of the resting base-line power spectrum, the background power spectrum, the respiration component, and the cardiac component were found to be linearly dependent on TE.
使用功能磁共振成像（fMRI）对闪烁频率的神经反应进行了详细测量。fMRI信号在人类V1区的闪烁频率为8 Hz时达到峰值，这与之前的正电子发射断层扫描（PET）和fMRI实验结果一致。测量了对不同持续时间的闪烁刺激的血流动力学反应的调制幅度。在短于6.7秒的时间段内，未观察到血流动力学反应受神经调制的影响。对刺激呈现频率的血氧水平依赖（BOLD）反应与相同频率下的基线功率谱之间的相似性表明，相同的潜在机制可能对两条曲线都起作用，并且基线fMRI功率谱可能归因于大脑中的基线电活动。发现静息基线功率谱、背景功率谱、呼吸成分和心脏成分的积分与回波时间（TE）呈线性相关。
