Jobert M, Kranda K, Duchêne J
PAREXEL GmbH, Independent Pharmaceutical Research Organization, Berlin, Germany.
Neuropsychobiology. 1996;34(3):166-74. doi: 10.1159/000119319.
Physiological signals recorded after presentation of a stimulus can be considered as the sum of an evoked sensory response and uncorrelated noise corresponding to the spontaneous neural background activity. In case of low signal-to-noise ratio, the sensory signal is estimated by averaging a large number of single trial records sampled under the same experimental conditions. The averaging technique, however, is inappropriate for displaying trial-to-trial variations that may occur during a recording session. A method based on matched filtering was developed for processing single visual evoked potentials (VEPs). To illustrate the performance of this method, a set of VEPs for grating patches of 8 different contrasts (including 0) was evaluated. The VEPs were subjected to signal detection analysis by computing for each contrast similarity indices between the single trial records and the averaged response used as a template. The signals were analysed in terms of probability density distributions, expressing the goodness of fit between template and each single waveform.
在呈现刺激后记录的生理信号可被视为诱发的感觉反应与对应于自发神经背景活动的不相关噪声之和。在信噪比低的情况下，通过对在相同实验条件下采样的大量单次试验记录进行平均来估计感觉信号。然而，平均技术不适用于显示记录过程中可能出现的逐次试验变化。开发了一种基于匹配滤波的方法来处理单个视觉诱发电位（VEP）。为了说明该方法的性能，评估了一组针对8种不同对比度（包括0）的光栅斑块的VEP。通过计算单次试验记录与用作模板的平均反应之间的每个对比度相似性指数，对VEP进行信号检测分析。根据概率密度分布对信号进行分析，该分布表示模板与每个单个波形之间的拟合优度。
