Trimmel M
Electroencephalogr Clin Neurophysiol. 1987 Jan;66(1):71-4. doi: 10.1016/0013-4694(87)90140-4.
The study was undertaken to elaborate the influence of slow potential shifts preceding S1 on the CNV. Eighteen subjects participated in a forewarned reaction time task. The EEG was recorded from F3, F4, Cz, P3 and P4 referred to linked mastoids. Selected averages of EOG-corrected trials with negative, positive and no shifts greater than 8 microV - within 2 sec before S1 at the respective location - were compared. Results showed greater CNV after positive shifts compared to negative shifts (P less than 0.05) and no significant interaction with location. Slow potential shifts before S1 did not affect reaction time. Evidence of a baseline effect is discussed as a ceiling effect as well as an expression of an active regulatory mechanism responsible for a desired activation at S2. As slow potentials may also interact with task conditions, it is suggested first to control the baseline in order to obtain reliable CNV measures, and secondly to use baseline effects as a tool to get insight into brain regulatory mechanisms.
本研究旨在阐述S1之前的慢电位变化对关联性负变（CNV）的影响。18名受试者参与了一项预先告知的反应时间任务。脑电图记录于F3、F4、Cz、P3和P4电极，参考双侧乳突。比较了在各自位置S1前2秒内，眼电校正后的试验中负向、正向和无大于8微伏变化的选定平均值。结果显示，正向变化后的CNV大于负向变化（P小于0.05），且与位置无显著交互作用。S1之前的慢电位变化不影响反应时间。讨论了基线效应的证据，认为其是一种天花板效应，也是负责S2期所需激活的主动调节机制的一种表现。由于慢电位也可能与任务条件相互作用，建议首先控制基线以获得可靠的CNV测量值，其次将基线效应作为一种工具来深入了解大脑调节机制。
