在执行精确时间内产生预期眼动的任务时,猕猴的反应时间呈现双峰分布.对这一现象,本文设计了包含大脑皮层的顶内沟外侧区(lateral intraparietal area,LIP)和辅助眼区(supplementary eye fields,SEF)、基底节(basal ganglia,BG)与上丘脑(superior colliculus,SC)在内的并行神经环路模型,通过计算模拟复现出双峰分布.本文探究了该分布的神经机制,发现SEF和LIP神经元群体之间的竞争过程导致了2个峰的出现,并且SEF脑区主要负责预期性眼动,主导了第1个峰的出现,LIP脑区主要负责由视觉刺激引发的反应性眼动,主导了第2个峰的出现.本文进一步地讨论了影响双峰分布形态的关键参数,从计算神经科学的角度探索了时间预期执行的过程.

IntroductionWorking memory (WM) plays a key role in many cognitive processes, and great interest has been attracted by WM for many decades. Recently, it has been observed that the reports of the memorized color sampled from a uniform distribution are clustered, and the report error for the stimulus follows a Gaussian distribution.MethodsBased on the well-established ring model for visuospatial WM, we constructed a spiking network model with heterogeneous connectivity and embedded short-term plasticity (STP) to investigate the neurodynamic mechanisms behind this interesting phenomenon.ResultsAs a result, our model reproduced the clustering report given stimuli sampled from a uniform distribution and the error of the report following a Gaussian distribution. Perturbation studies showed that the heterogeneity of connectivity and STP are necessary to explain experimental observations.ConclusionOur model provides a new perspective on the phenomenon of visual WM in experiments.

Patterns out of homogeneous equilibrium on monolayer networks have been well-documented. However, it is a challenge to understand patterns on multiplex networks. In this work, we study coupled FitzHugh- Nagumo model on duplex networks consisting of two layers. By numerical investigations, we find that the emergent patterns may be characterized by dominant network modes when the homogeneous equilibrium becomes unstable. These dominant network modes on duplex networks are related to the most unstable network modes in monolayer networks. Using these dominant networks modes, we develop approximation methods to deal with the instability of the homogeneous equilibrium on duplex networks. The comparison between theoretical and numerical results suggests that the approximation methods may serve as a tool for analyzing patterns on duplex networks. (c) 2021 Elsevier Ltd. All rights reserved.

Synchronization is one of important collective behaviors in various systems. The identification of different synchronous dynamics and types of transition between different dynamical states has drawn great interests. In this work, we study Kuramoto model in the presence of correlation between coupling strength and natural frequency. By manipulating the correlation between coupling strength and natural frequency, synchronization transition can either be the continuous type or the discontinuous one. Rich synchronous dynamics and different transitions between them can be realized by manipulating the correlation. We hope that the coupled systems with correlation between coupling strength and natural frequency could provide a general platform to investigate synchronous dynamics. (c) 2021 Elsevier Ltd. All rights reserved.

In globally coupled phase oscillators, the natural frequency distribution plays a critical role on the synchronization. In this work, we consider globally coupled phase oscillators with a multi-peak natural frequency distribution, that is a superposition of two symmetrical bimodal Lorentzian distributions. Using Ott-Antonsen (OA) dimension reduction technique, we reduce the system from high dimension to low dimension, and investigate its dynamical behaviors in detail. Rich dynamical phenomena including revived incoherent states are found. Different types of partial synchronous states are characterized. We further investigate the phenomenon of revived incoherent states in a different view by modifying the model to a system composed of two interacting subpopulations of phase oscillators. (C) 2019 Elsevier B.V. All rights reserved.

Nonlocally coupled systems may display fascinating dynamics such as chimera states. In this work, we report an intriguing pattern formation, intermingled traveling waves, in a ring of nonlocally coupled FitzHugh-Nagumo oscillators. For intermingled traveling waves with even number of traveling pulses, oscillators are spontaneously partitioned into two groups and each of them supports its own traveling pulses. Oscillators from different groups may be well mixed for random initial conditions. Adjacent oscillators perform the periodic oscillation with the same frequency and they may be in antiphase if belonging to different groups. For intermingled traveling waves with odd number of traveling pulses, possible antiphase between adjacent oscillators renders the state to possess character of Möbius strip. The stabilities of intermingled traveling waves are numerically investigated and the stability diagrams in different parameter planes are presented.

Though the complete chaos synchronization on single-layer networks has been well understood, it is still a challenge on multiplex networks. In this work, we study the complete chaos synchronization on time-dependent duplex networks in which interaction pattern among oscillators alternates periodically between two single-layer networks. The alternations between two layers are characterized by the offset strength A and the switching frequency ω. We find that there are two dynamical regimes depending on ω. For high ω, the critical A for the stable complete synchronization is independent of ω and the fast-switching approximation suggests that the time-dependent duplex networks can be approximated by the time-independent duplex networks with effective coupling strength. For low ω, the critical A depends on ω nonmonotonically. At extremely low ω, the estimation of the critical A can be obtained by a single-mode approximation taking one dominant transversal network mode to complete synchronization into considerations.