A new method to determine temporal variability in the period of pre-movement electroencephalographic activity
A new method to determine temporal variability in the period of pre-movement electroencephalographic activity
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DOI：
10.1016/j.ijpsycho.2008.08.006
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发表时间：
2008-12-01
影响因子：
3
通讯作者：
Lindinger, Gerald
中科院分区：
文献类型：
--
作者：
Dirnberger, Georg;Lang, Wilfried;Lindinger, Gerald
准备电位 (RP) 是一种缓慢的脑电图 (EEG) 运动前电位，在早期研究中用于确定随意运动之前的神经过程的开始和顺序。这些研究中的潜伏期始终根据平均 RP 计算，而个别试验的起始时间仍然无法获得。本研究的目的是使用不同的统计方法来检查受试者中单试验 RP 的发生有多大差异。我们记录了 15 名惯用右手的健康受试者的 RP，同时他们用惯用的右手进行自定进度的重复单侧按钮按下。偏度是分布不对称性的一种度量，在单试验 RP 组中进行分析，以区分固定起始模型和可变起始模型。结果表明，所有电极和运动前间隔的偏度值都在零附近，没有任何显着偏差。使用具有固定起始时间的建模数据复制了原始数据获得的结果，而具有可变起始时间的替代模型（即，包括异常早期起始的试验）显示出偏度与零的显着偏差。总之，对于用惯用手进行的简单重复运动，这些结果证实了 RP 的固定起始模型，在整个试验中具有相似的运动前皮层激活起始时间。该方法也可能适用于其他范式来测试心理计时的基本假设。 (c) 2008 Elsevier B.V. 保留所有权利。
The readiness potential (RP), a slow electroencephalographic (EEG) pre-movement potential, was used in earlier studies to determine the onset and order of neural processes preceding voluntary movement. Latencies in these studies were always calculated from the averaged RP, whereas onset times of individual trials remained inaccessible. The aim of this study was to use a different, statistical approach to examine how variable the onset of single-trial RPs within subjects is. We recorded RPs in 15 right-handed healthy subjects while they made self-paced repetitive unilateral button presses with their dominant right hand. Skewness, a measure of distribution asymmetry, was analysed in sets of single-trial RPs to discriminate between fixed onset and variable onset models. Results show that skewness has values around zero across all electrodes and pre-movement intervals without any significant deviation. This result obtained for the original data was replicated using modelled data with fixed onset times, whereas alternative models with variable onset times (i.e., including trials with exceptionally early onset) showed significant deviations of skewness from zero. In conclusion, for simple repetitive movements with the dominant hand these results confirm a fixed onset model of the RP with similar onset times of pre-movement cortical activation across trials. The methodology might be also applicable for other paradigms to test basic assumptions of mental chronometry. (c) 2008 Elsevier B.V. All rights reserved.