Menaker M, Eskin A
Science. 1967 Sep 8;157(3793):1182-5. doi: 10.1126/science.157.3793.1182.
A technique has been developed for effectively separating the direct inductive effect of a light signal from its effect on the phase of the rhythm of sensitivity to photoperiodic induction. With this technique it has been shown that a 75-minute pulse of light per day, when appropriately positioned with respect to the circadian activity cycle of the sparrow Passer domesticus, is sufficient to produce a response normally produced only by long days. The results cannot be interpreted in terms of a requirement of an absolute amount of either darkness or light and offer strong confirmation of Bünning's hypothesis concerning the mechanism of photoperiodic time measurement.
已开发出一种技术，可有效地将光信号的直接诱导效应与其对光周期诱导敏感性节律相位的影响区分开来。利用该技术已表明，每天75分钟的光脉冲，当相对于家麻雀（Passer domesticus）的昼夜活动周期适当地定位时，足以产生通常仅由长日照产生的反应。这些结果不能用对绝对黑暗或光照量的要求来解释，有力地证实了比宁（Bünning）关于光周期时间测量机制的假说。
