Shepherd Daniel, Hautus Michael J
Psychophysics Laboratory, Department of Psychology, University of Auckland, Private Bag 92019, Auckland, New Zealand.
Atten Percept Psychophys. 2009 Nov;71(8):1931-40. doi: 10.3758/APP.71.8.1931.
Stochastic resonance is a mechanism that improves the detection of weak periodic signals when an optimal level of background noise is present. This counterintuitive concept is thought to involve a cooperative effect that arises out of a physical coupling between deterministic and random dynamics in nonlinear systems. We report the results of three psychophysical experiments designed to probe the auditory system for evidence of stochastic resonance. In all three experiments, participants judged which of two 1000-Hz tones was greater in intensity, with one of the tones embedded in a background of Gaussian noise. Experiment 1 used a two-alternative forced choice task and provided evidence of enhanced discriminability at an optimal level of noise. The aim of Experiment 2 was to determine whether the apparent enhancement observed in Experiment 1 was due to sensory processes or to a response bias. Receiver operating characteristic analysis supported an explanation based on decision processes, rather than a genuine sensory enhancement. An additional experiment (Experiment 3) was used to discount experimental artifacts.
随机共振是一种机制，当存在最佳水平的背景噪声时，它能改善对微弱周期性信号的检测。这个违反直觉的概念被认为涉及一种协同效应，这种效应源自非线性系统中确定性动力学和随机动力学之间的物理耦合。我们报告了三项心理物理学实验的结果，这些实验旨在探究听觉系统中随机共振的证据。在所有三项实验中，参与者判断两个1000赫兹音调中哪个强度更大，其中一个音调嵌入高斯噪声背景中。实验1使用了二选一强制选择任务，并提供了在最佳噪声水平下可辨别性增强的证据。实验2的目的是确定在实验1中观察到的明显增强是由于感觉过程还是反应偏差。接受者操作特征分析支持基于决策过程的解释，而不是真正的感觉增强。另外一项实验（实验3）用于排除实验假象。
