Levin J E, Miller J P
Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA.
Nature. 1996 Mar 14;380(6570):165-8. doi: 10.1038/380165a0.
Sensory systems are often required to detect a small amplitude signal embedded in broadband background noise. Traditionally, ambient noise is regarded as detrimental to encoding accuracy. Recently, however, a phenomenon known as stochastic resonance has been described in which, for systems with a nonlinear threshold, increasing the input noise level can actually improve the output signal-to-noise ratio over a limited range of signal and noise strengths. Previous theoretical and experimental studies of stochastic resonance in physical and biological systems have dealt exclusively with single-frequency sine stimuli embedded in a broadband noise background. In the past year it has been shown in a theoretical and modelling study that stochastic resonance can be observed with broadband signals. Here we demonstrate that broadband stochastic resonance is manifest in the peripheral layers of neural processing in a simple sensory system, and that it plays a role over a wide range of biologically relevant stimulus parameters. Further, we quantify the functional significance of the phenomenon within the context of signal processing, using information theory.
感觉系统常常需要检测嵌入在宽带背景噪声中的小幅度信号。传统上，环境噪声被认为对编码准确性有害。然而，最近描述了一种称为随机共振的现象，即对于具有非线性阈值的系统，在信号和噪声强度的有限范围内增加输入噪声水平实际上可以提高输出信噪比。以往对物理和生物系统中随机共振的理论和实验研究仅涉及嵌入宽带噪声背景中的单频正弦刺激。在过去的一年里，一项理论和建模研究表明，宽带信号也能观察到随机共振。在这里，我们证明宽带随机共振在一个简单感觉系统的神经处理外周层中表现出来，并且它在广泛的生物学相关刺激参数范围内发挥作用。此外，我们使用信息论在信号处理的背景下量化了该现象的功能意义。
