Ashida Go, Carr Catherine E
Department of Biology, University of Maryland, College Park MD, USA.
Front Neurosci. 2010 Sep 30;4. doi: 10.3389/fnins.2010.00172. eCollection 2010.
Phase-locked spikes in various types of neurons encode temporal information. To quantify the degree of phase-locking, the metric called vector strength (VS) has been most widely used. Since VS is derived from spike timing information, error in measurement of spike occurrence should result in errors in VS calculation. In electrophysiological experiments, the timing of an action potential is detected with finite temporal precision, which is determined by the sampling frequency. In order to evaluate the effects of the sampling frequency on the measurement of VS, we derive theoretical upper and lower bounds of VS from spikes collected with finite sampling rates. We next estimate errors in VS assuming random sampling effects, and show that our theoretical calculation agrees with data from electrophysiological recordings in vivo. Our results provide a practical guide for choosing the appropriate sampling frequency in measuring VS.
各种类型神经元中的锁相尖峰编码时间信息。为了量化锁相程度，称为矢量强度（VS）的指标得到了最广泛的应用。由于VS源自尖峰时间信息，尖峰发生测量中的误差应会导致VS计算中的误差。在电生理实验中，动作电位的时间是以有限的时间精度检测的，这由采样频率决定。为了评估采样频率对VS测量的影响，我们从以有限采样率收集的尖峰中推导出VS的理论上限和下限。接下来，我们假设随机采样效应来估计VS中的误差，并表明我们的理论计算与体内电生理记录的数据一致。我们的结果为在测量VS时选择合适的采样频率提供了实用指南。
