Kripke Daniel F, Clopton Paul, Marler Matthew R, Youngstedt Shawn D, Elliott Jeffrey A
Department of Psychiatry, University of California, San Diego, California 92093-0667, USA.
Chronobiol Int. 2003 Nov;20(6):1117-23. doi: 10.1081/cbi-120025535.
This communication presents a new method for evaluating phase response curves (PRCs). A PRC describes the phase shifts produced in an oscillator by stimuli applied at different initial phase-states of that oscillator. In the PRC bisection tests, we repeatedly cut in half the circular distribution of the initial phase-states of the oscillator when stimuli are given. Empirically, we locate that optimal diameter which best bisects the circular distribution of phase responses into arcs of relative phase advance and phase delay. We compute a D score reflecting the success of the best bisection. The null hypothesis of a random distribution of phase responses by initial phase is tested with a Monte Carlo procedure, which computes Dr scores from random combinations of phase shifts with initial phases, thus determining the probability, given the null hypothesis, that the observed D score was from a random distribution. The bisection procedure can be extended to examine whether stronger phase shifts are produced in one phase response curve than in contrasting curves. Also, the bisection procedure yields an estimate of the inflection point of the phase response curve. A method is given to estimate the power of the PRC bisection test.
本通讯介绍了一种评估相位响应曲线（PRC）的新方法。PRC描述了在振荡器的不同初始相位状态下施加刺激时，该振荡器产生的相位偏移。在PRC二等分测试中，当给予刺激时，我们反复将振荡器初始相位状态的圆形分布一分为二。根据经验，我们找出能将相位响应的圆形分布最佳地二等分为相对相位提前和相位延迟弧的最佳直径。我们计算一个反映最佳二等分成功程度的D分数。通过蒙特卡洛程序检验初始相位的相位响应随机分布的零假设，该程序从相位偏移与初始相位的随机组合中计算Dr分数，从而在零假设下确定观察到的D分数来自随机分布的概率。二等分程序可以扩展，以检验一条相位响应曲线是否比对比曲线产生更强的相位偏移。此外，二等分程序还能估计相位响应曲线的拐点。给出了一种估计PRC二等分测试功效的方法。
