Hatem S M, Plaghki L, Mouraux A
Unité de Réadaptation et de Médecine Physique, Université Catholique de Louvain, Belgium.
Clin Neurophysiol. 2007 Jul;118(7):1503-16. doi: 10.1016/j.clinph.2007.03.021. Epub 2007 May 1.
To examine and compare the modulation of nociceptive somatosensory laser-evoked potentials (LEPs) and non-nociceptive somatosensory electrically-evoked potentials (SEPs) by brain processes related to response inhibition.
A warning auditory tone was followed by either an electrical or a laser stimulus. Subjects performed a Go/Nogo task in which they were instructed to respond to the laser stimulus and refrain from responding to the electrical stimulus in half of the runs. In the other half, they performed the opposite. The paradigm allowed a direct, within-subject comparison of the electrophysiological correlates of brain processes related to the Go/Nogo task in both somatosensory submodalities.
In the Nogo-condition, SEPs displayed an enhanced N120 (early Nogo-response), a reduced vertex P240 and enhanced frontal P3 (late Nogo-responses). In contrast, LEPs only displayed late Nogo-related responses (reduced vertex P350 and enhanced frontal P3).
The early Nogo-related enhancement of SEPs may reflect brain processes specific to the processing of non-nociceptive somatosensory stimuli. Later components of the Nogo-response may reflect cortical activity common to the processing of both nociceptive and non-nociceptive somatosensory stimuli.
Response inhibition significantly modulates both LEPs and SEPs. Part of these activities may be specific of the eliciting stimulus modality.
研究并比较与反应抑制相关的脑过程对伤害性躯体感觉激光诱发电位（LEP）和非伤害性躯体感觉电诱发电位（SEP）的调制作用。
先呈现一个警示听觉音调，随后施加电刺激或激光刺激。受试者执行一个Go/NoGo任务，在一半的试验中，他们被要求对激光刺激做出反应，而对电刺激不做反应。在另一半试验中，要求则相反。该范式允许在同一受试者内直接比较两种躯体感觉亚模态中与Go/NoGo任务相关的脑过程的电生理相关性。
在NoGo条件下，SEP显示出N120增强（早期NoGo反应）、头顶P240降低以及额叶P3增强（晚期NoGo反应）。相比之下，LEP仅显示出与NoGo相关的晚期反应（头顶P350降低和额叶P3增强）。
SEP早期与NoGo相关的增强可能反映了非伤害性躯体感觉刺激处理特有的脑过程。NoGo反应的后期成分可能反映了伤害性和非伤害性躯体感觉刺激处理共有的皮质活动。
反应抑制显著调制LEP和SEP。这些活动的一部分可能特定于诱发刺激模态。
