Skuse N F, Burke D
Unit of Clinical Neurophysiology, Prince Henry Hospital, School of Medicine, University of New South Wales, Sydney, Australia.
Electroencephalogr Clin Neurophysiol. 1990 May-Jun;77(3):199-204. doi: 10.1016/0168-5597(90)90038-f.
The optimal bandwidth for recording the visual evoked potential (VEP) to pattern reversal was investigated in 8 normal subjects by re-analyzing off-line data recorded on tape using an open bandwidth of 0.1 Hz-3 kHz. Power spectral analysis of the VEP revealed little energy above 50 Hz. With digital filtering, the amplitude N70-P100 was significantly attenuated only when the low-pass filter was reduced to 50 Hz or when the high-pass filter was raised to 8 Hz. With analogue filtering, there was significant prolongation of latency of P100 when the low-pass filter (12 dB/octave) was reduced to 250 Hz and a significant decrease in latency when the high-pass filter (6 dB/octave) exceeded 3 Hz. However, the effects of analogue filtering were not uniform across subjects: in 2 subjects the latency of P100 was prolonged using a low-pass filter of 600 Hz and in 2 other subjects the latency was shortened when the 1 Hz high-pass filter was introduced. If a restricted bandwidth is used, non-uniform distortion of latency could make a significant contribution to the variability in latency of P100. The optimal bandwidth is one which minimises this contribution to the variability, 0.3 Hz to greater than 600 Hz.
通过对使用0.1Hz至3kHz开放带宽记录在磁带上的离线数据进行重新分析，研究了8名正常受试者记录模式反转视觉诱发电位（VEP）的最佳带宽。VEP的功率谱分析显示，50Hz以上几乎没有能量。通过数字滤波，仅当低通滤波器降至50Hz或高通滤波器升至8Hz时，N70 - P100波幅才会显著衰减。通过模拟滤波，当低通滤波器（12dB/倍频程）降至250Hz时，P100潜伏期显著延长；当高通滤波器（6dB/倍频程）超过3Hz时，潜伏期显著缩短。然而，模拟滤波的效果在受试者之间并不一致：2名受试者使用600Hz低通滤波器时P100潜伏期延长，另外2名受试者引入1Hz高通滤波器时潜伏期缩短。如果使用受限带宽，潜伏期的不均匀失真可能会对P100潜伏期的变异性产生显著影响。最佳带宽是使这种对变异性的影响最小化的带宽，即0.3Hz至大于600Hz。
