神经系统疾病与认知动力学(II): 神经振荡与认知动力学

大脑神经系统具有从慢到快多种不同的振荡节律, 这些节律振荡被认为参与了大脑多种功能的实现, 其中高频的伽马同步振荡被认为与大脑的认知功能最为相关. 本文阐述了生物学实验方面关于伽马振荡及其功能的研究进展, 并针对实验中伽马振荡的频率敏感依赖于外部刺激特征的现象, 综述了基于神经网络模型进行变频伽马振荡及其认知功能的动力学建模研究工作, 解释了视觉刺激调控的变频率伽马振荡动力学产生机理, 提出了基于同步抑制增强全局放电率对比度的神经认知机制. 研究成果有助于理解神经系统同步振荡的产生机理及其认知作用, 为大脑认知原理以及类脑智能的研究奠定基础. 

Neurological disease and cognitive dynamics (II): Neural oscillations and cognitive dynamics

The brain nervous system has various oscillatory rhythms, from slow to fast. These rhythmic oscillations are believed to be involved in the realization of various brain functions. The high-frequency Gamma synchronous oscillations are considered to be most related to the cognitive functions of the brain. In this review paper, the research progress of Gamma oscillations and their functions in biological experiments is expounded. Then, concerning the biological observation that the frequency of Gamma oscillations sensitively depends on the characteristics of external stimuli, the dynamical modeling work on the variable-frequency Gamma oscillations and the cognitive functions based on neural network models is also expounded. In this paper, the generation mechanisms of variable-frequency Gamma oscillation dynamics regulated by visual stimuli are explained, and a neurocognitive mechanism of global enhancement of firing rate contrast based on synchronous inhibition is proposed. The research results are helpful to understand the generation mechanisms of synchronous oscillations of nervous system and the cognitive functions and lay a foundation for the study of brain working mechanisms of cognitive activities and brain-like intelligence.