Richter F, Wicher C, Schmidt D, Leichsenring A, Haschke W
Institut für Physiologie, Jena, F.R.G.
Neurosci Lett. 1992 Jan 20;135(1):133-5. doi: 10.1016/0304-3940(92)90153-x.
Visually evoked potentials (VEP) were recorded chronically from occipital cortex in awake rabbits. The VEP typically consisted of a triphasic response (positive deflection P60--negative deflection N205--positive deflection P450) that was followed by a late negative shift starting about 750 ms after the eliciting flash. After computation of a discriminating amplitude value (200 or 250 microV) the VEP were divided for comparison in high- and low-amplitude groups. Significant differences between these groups existed in amplitudes and latencies of the early VEP components. High-amplitude VEP were followed by larger late negative shifts and had significantly (P less than 0.01) earlier second positive deflections. In these high-amplitude cases, the EEG-baseline was more negative than in the low-amplitude VEP. In addition, we found a more synchronized background EEG in the low-amplitude VEP group. We conclude that different VEP amplitudes depended on different activation states of the cortex which could be changed by reinforcement.
在清醒的兔子身上，从枕叶皮质长期记录视觉诱发电位（VEP）。VEP通常由一个三相反应组成（正向偏转P60 - 负向偏转N205 - 正向偏转P450），随后是一个在诱发闪光后约750毫秒开始的晚期负向偏移。在计算出一个区分幅度值（200或250微伏）后，将VEP分为高幅度组和低幅度组进行比较。这些组之间在早期VEP成分的幅度和潜伏期存在显著差异。高幅度VEP之后是更大的晚期负向偏移，并且第二个正向偏转明显更早（P小于0.01）。在这些高幅度情况下，脑电图基线比低幅度VEP更负。此外，我们发现在低幅度VEP组中背景脑电图更同步。我们得出结论，不同的VEP幅度取决于皮质的不同激活状态，而这种状态可通过强化改变。
