Klemm W R, Goodson R A, Allen R G
Brain Res Bull. 1984 Aug;13(2):287-91. doi: 10.1016/0361-9230(84)90129-1.
Steady-state stimuli are repeated continuously at a frequency that evokes averaged EEG waveforms with components at a frequency which is the same or some multiple of the stimulus rate. A variety of stimulus parameters are readily manipulated and controlled. We wished to assess the suitability of this approach for animal experimentation, and chose to evaluate steady-state visual evoked potential (VEP) responses to counterphased checkerboard stimuli in anesthetized adult male Rhesus monkeys. Large VEPs were reliably produced over the range of 3-6 Hz reversal rate; at 10 Hz, the VEP spectral power was clearly diminished in all monkeys. At each given reversal rate, monkeys differed substantially in variability and amount (up to 3-fold) of spectral power. These large inter-subject differences paralleled what we have seen in similar studies of unanesthetized humans. All monkeys developed large VEPs at the midline, but the topographic distribution of maximum VEP was not uniform; in 3 monkeys the power was much greater over one hemisphere than the other. Fatigue or habituation was not evident; in each monkey, there were usually no significant differences in VEP power over the 3 consecutive 30 sec segments of a given stimulation. We conclude that the anesthetized monkey can be a suitable model for study of steady-state phenomena, as long as the proper stimulus parameters are employed and as long as the level of variance is taken into account.
稳态刺激以一定频率持续重复，该频率能诱发平均脑电图波形，其成分频率与刺激速率相同或为刺激速率的某个倍数。多种刺激参数易于操控和控制。我们希望评估这种方法用于动物实验的适用性，于是选择在麻醉的成年雄性恒河猴中评估对反相棋盘格刺激的稳态视觉诱发电位（VEP）反应。在3 - 6Hz的反转率范围内能可靠地产生大的VEP；在10Hz时，所有猴子的VEP频谱功率明显降低。在每个给定的反转率下，猴子在频谱功率的变异性和幅度（高达3倍）方面存在很大差异。这些个体间的巨大差异与我们在对未麻醉人类的类似研究中所观察到的情况相似。所有猴子在中线处都产生了大的VEP，但最大VEP的地形分布并不均匀；在3只猴子中，一个半球上的功率比另一个半球大得多。疲劳或习惯化并不明显；在每只猴子中，在给定刺激的连续3个30秒时间段内，VEP功率通常没有显著差异。我们得出结论，只要采用适当的刺激参数并考虑到方差水平，麻醉的猴子可以成为研究稳态现象的合适模型。
