Relationships between attention effects and intensity effects on the cognitive N140 and P300 components of somatosensory ERPs
Relationships between attention effects and intensity effects on the cognitive N140 and P300 components of somatosensory ERPs
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DOI：
10.1016/s1388-2457(00)00383-7
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发表时间：
2000-10-01
影响因子：
4.7
通讯作者：
Imamura, N
中科院分区：
文献类型：
--
作者：
Nakajima, Y;Imamura, N
目的：本研究试图阐明外源性和内源性成分的相对贡献N140和P300电位引起的体感stimulation.Methods：体感事件相关电位（ERPs）使用奇数球范式与频繁（80%）的刺激传递到左手食指和罕见（20%）的刺激传递到右手食指。在每个实验中，两种类型的刺激具有相同的强度。使用6种不同的刺激强度重复实验，范围从感觉阈值到阈值的3倍。每个实验在两种条件下进行。在一个实验中，受试者被要求数数并对不常见的刺激做出反应。在另一个实验中，受试者被指示忽略频繁或不频繁的刺激。此外，右正中神经的复合感觉电位分别记录从电极在手腕上使用相同的范围的刺激强度施加到右手食指。有人注意和无人注意的不频繁刺激引起的N140和P300的振幅作为刺激强度的函数以平行的方式增加，因此，有注意和无注意反应之间的幅度差异与刺激强度无关。腕部复合感觉神经电位的波幅与N140和P300的波幅具有相似的斜率。结论：头皮N140和P300由内源性成分和外源性成分组成，内源性成分与刺激强度无关，外源性成分随刺激强度的增加而增加。本文还讨论了这些成分对N140和P300振幅的相对贡献。(C)2000爱思唯尔科学爱尔兰有限公司保留所有权利。
Objectives: This study attempts to elucidate the relative contributions of exogenous and endogenous components to the N140 and P300 potentials elicited by somatosensory stimulation.Methods: Somatosensory event-related potentials (ERPs) were evoked using an odd-ball paradigm with the frequent (80%) stimuli delivered to the left index finger and the infrequent (20%) stimuli delivered to the right index finger. Both types of stimuli had the same intensity within each experiment. The experiment was repeated using 6 different stimulus intensities ranging from the sensory threshold to 3 times the threshold. Each experiment was done under two conditions. In one, the subjects were asked to count and respond to the infrequent stimuli. In the other, the subjects were instructed to ignore the stimuli whether frequent or infrequent. In addition, the compound sensory potential of the right median nerve was separately recorded from electrodes at the wrist using the same range of stimulus intensities applied to the right index finger.Results: Amplitudes of the N140 and P300 elicited by both attended and unattended infrequent stimuli increased in a parallel fashion as a function of stimulus intensity, so that the amplitude difference between attended and unattended responses was independent of the stimulus intensity. The amplitude of the compound sensory nerve potential at the wrist exhibited a similar slope to those of the N140 and P300.Conclusions: Thus, it is concluded that the scalp N140 and P300 consist of two components: an endogenous component, which is independent of the stimulus intensity, and an exogenous component, which increases as a function of stimulus intensity. The relative contribution of these components to the N140 and P300 amplitudes is also discussed. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.