Babiloni Claudio, Brancucci Alfredo, Babiloni Fabio, Capotosto Paolo, Carducci Filippo, Cincotti Febo, Arendt-Nielsen Lars, Chen Andrew C N, Rossini Paolo Maria
Dipartimento di Fisiologia Umana e Farmacologia, Sezione di EEG ad Alta Risoluzione, Università degli Studi di Roma La Sapienza, P. le Aldo Moro 5, 00185 Rome, Italy.
Eur J Neurosci. 2003 Sep;18(6):1692-700. doi: 10.1046/j.1460-9568.2003.02851.x.
In the present study, high-resolution electroencephalography techniques modelled the spatiotemporal pattern of human anticipatory cortical responses preceding expected galvanic painful stimuli (non-painful stimuli as a control). Do these responses reflect the activation of associative other than somatosensory systems? Anticipatory processes were probed by alpha oscillations (6-12 Hz) for the evaluation of thalamocortical channels and by negative event-related potentials for the evaluation of cortical excitability. Compared with the control condition, a progressive reduction of the alpha power was recognized over the primary somatosensory cortex from 2 s before the painful stimulation. In contrast, the anticipatory event-related potentials were negligible during the expectancy period. The results on the alpha power suggest that the expectancy of the painful stimulation specifically facilitated the somatosensory thalamocortical channel. Remarkably, the associative frontal-parietal areas were not involved, possibly due to the predictable and repetitive features of the painful stimulus. The present results also suggest that negative event-related potentials are modest preceding warned stimuli (even if painful) with a simple information content.
在本研究中，高分辨率脑电图技术模拟了人类在预期的电刺激疼痛刺激（以非疼痛刺激作为对照）之前的预期皮层反应的时空模式。这些反应是否反映了除体感系统之外的联合系统的激活？通过α振荡（6 - 12赫兹）探测预期过程以评估丘脑皮质通道，并通过负性事件相关电位评估皮质兴奋性。与对照条件相比，在疼痛刺激前2秒开始，初级体感皮层上的α功率逐渐降低。相反，预期事件相关电位在预期期内可忽略不计。α功率的结果表明，疼痛刺激的预期特别促进了体感丘脑皮质通道。值得注意的是，联合性额顶叶区域未参与其中，这可能是由于疼痛刺激具有可预测和重复性的特征。目前的结果还表明，对于具有简单信息内容的预先警告的刺激（即使是疼痛刺激），负性事件相关电位较小。
