University Medical Center Hamburg-Eppendorf.
J Cogn Neurosci. 2014 Jul;26(7):1469-80. doi: 10.1162/jocn_a_00537. Epub 2013 Dec 17.
In neural systems, information processing can be facilitated by adding an optimal level of white noise. Although this phenomenon, the so-called stochastic resonance, has traditionally been linked with perception, recent evidence indicates that white noise may also exert positive effects on cognitive functions, such as learning and memory. The underlying neural mechanisms, however, remain unclear. Here, on the basis of recent theories, we tested the hypothesis that auditory white noise, when presented during the encoding of scene images, enhances subsequent recognition memory performance and modulates activity within the dopaminergic midbrain (i.e., substantia nigra/ventral tegmental area, SN/VTA). Indeed, in a behavioral experiment, we can show in healthy humans that auditory white noise-but not control sounds, such as a sinus tone-slightly improves recognition memory. In an fMRI experiment, white noise selectively enhances stimulus-driven phasic activity in the SN/VTA and auditory cortex. Moreover, it induces stronger connectivity between SN/VTA and right STS, which, in addition, exhibited a positive correlation with subsequent memory improvement by white noise. Our results suggest that the beneficial effects of auditory white noise on learning depend on dopaminergic neuromodulation and enhanced connectivity between midbrain regions and the STS-a key player in attention modulation. Moreover, they indicate that white noise could be particularly useful to facilitate learning in conditions where changes of the mesolimbic system are causally related to memory deficits including healthy and pathological aging.
在神经系统中，通过添加最佳水平的白噪声可以促进信息处理。尽管这种现象，即所谓的随机共振，传统上与感知有关，但最近的证据表明，白噪声也可能对认知功能产生积极影响，例如学习和记忆。然而，潜在的神经机制尚不清楚。在这里，基于最近的理论，我们测试了一个假设，即在场景图像编码期间呈现听觉白噪声可以增强随后的识别记忆表现，并调节多巴胺能中脑（即黑质/腹侧被盖区，SN/VTA）内的活动。事实上，在一项健康人类的行为实验中，我们可以证明听觉白噪声（而非控制声音，如正弦音）可略微提高识别记忆。在 fMRI 实验中，白噪声选择性地增强了 SN/VTA 和听觉皮层中的刺激驱动的相位活动。此外，它诱导了 SN/VTA 与右 STS 之间更强的连通性，而后者与白噪声引起的随后记忆改善呈正相关。我们的研究结果表明，听觉白噪声对学习的有益影响取决于多巴胺能神经调节以及中脑区域和 STS 之间增强的连通性——注意力调节的关键参与者。此外，它们表明白噪声在与记忆缺陷相关的条件下，特别是在健康和病理性衰老中，中脑系统的变化是因果关系的情况下，可能特别有助于促进学习。
