【摘要】 对近年发展起来的脑科学中的非线性问题作一介绍。这些问题得到脑科学界的广泛注意。它们是同步,混沌与混沌周游,噪声与随机共振。在很多不同背景下的神经生理实验表明脑皮层的振荡活动都存在同步与去同步现象。混沌在人与动物的脑中扮演着重要的角色,混沌周游与Freeman模型被认为与联想记忆或记忆的动态连接有关。适当噪声强度导致信噪比的极大提高——随机共振是脑神经系统能检测到极其微弱信号的工作机制。噪声也导致同步态并使之稳定。此外,噪声的一些其他作用也在本文中提及。更多还原

【Abstract】 We present here some nonlinear problems in brain science that were studied in recent years. They are synchronization, chaos and chaotic itinerancy, noise and stochastic resonance. Neurophysiological measurements in a variety of settings have shown that synchronization and desynchronization of the oscillatory activity exist in various cortical systems. Chaotic activities play an important role in the human and animal brains, chaotic itinerancy and the Freeman model are believed to be connected with the associative memory, or dynamic link of memory. Noise-induced great enhancement in the signal-to-noise ratio, called the stochastic resonance, is the mechanism of the brain neural system to detect very week signals, and noise can also induce and stabilize the synchronization state. Some of the other effects of noise are also discussed in this paper.更多还原