Anticipated Synchronization and Zero-Lag Phases in Population Neural Models

2018 ◽  
Vol 28 (08) ◽  
pp. 1830025 ◽  
Author(s):  
Germán César Dima ◽  
Mauro Copelli ◽  
Gabriel Bernardo Mindlin
Keyword(s):  
Dynamical System ◽  
Phase Difference ◽  
Negative Phase ◽  
Slave System ◽  
Neural Models ◽  
Neural Oscillators ◽  
Driven System ◽  
Song Production ◽  
Synchronization Regime ◽  
Lag Phases

Anticipated synchronization is a counterintuitive synchronization regime between a master and a slave dynamical system in which there is a negative phase difference between the driver and the driven system. By studying a set of simple neural oscillators, we unveil the dynamical mechanisms required to generate this phenomenon. We study master–slave configurations where the slave system is, when uncoupled, in a quiescent excitable state. We exemplify our results by describing the dynamics of a dynamical system proposed to model the part of a songbird’s brain involved in song production.

scholarly journals COUPLING AND FEEDBACK EFFECTS IN EXCITABLE SYSTEMS: ANTICIPATED SYNCHRONIZATION

2004 ◽  
Vol 18 (23) ◽  
pp. 1135-1155 ◽  
Author(s):  
MARZENA CISZAK ◽  
RAÚL TORAL ◽  
CLAUDIO MIRASSO
Keyword(s):  
Short Review ◽  
Coupled Systems ◽  
Dynamical Regime ◽  
Slave System ◽  
Physical Reason ◽  
Excitable Systems ◽  
Real Neuron ◽  
Anticipation Time ◽  
Model Equations ◽  
Synchronization Regime

This paper reviews our recent work on the synchronization of excitable systems in a master–slave configuration and when the slave system includes a delayed self-coupling term. Particularly, we address the existence of the so-called anticipated synchronization, i.e. a dynamical regime in which the slave system is able to reproduce in advance the evolution of the master. This is most remarkable since the anticipated synchronization appears even when the excitable spikes are induced by random terms, such as white noise. After providing a short review of the general theory of synchronization as well as the main features of excitable systems, we present numerical and experimental results in coupled excitable systems of the FitzHugh–Nagumo type driven by different types of noise. The experiments have been done in electronic implementations of the model equations. We present the conditions (values of the coupling intensity and delay time) for which the anticipated synchronization regime is a stable one and show that it is possible to increase the anticipation time by using a cascade of several coupled systems. We use a particular limit of the FitzHugh–Nagumo system, as well as a simple excitable model, to give evidence that the physical reason for the existence of anticipated synchronization is the lowering of the excitability threshold of the slave due to the coupling. Finally, we propose a hypothesis for a possible explanation of the zero-lag synchronization observed in some real neuron systems.

scholarly journals Behavioural responses to video and live presentations of females reveal a dissociation between performance and motivational aspects of birdsong

2019 ◽  
Author(s):  
Logan S. James ◽  
R. Fan ◽  
J.T. Sakata
Keyword(s):  
Courtship Song ◽  
Zebra Finches ◽  
Acoustic Features ◽  
Neural Models ◽  
Song Production ◽  
And Performance ◽  
And Control ◽  
Video Presentations ◽  
Insight Into ◽  
Social Behaviours

ABSTRACTUnderstanding the regulation of social behavioural expression requires insight into motivational and performance aspects of social behaviours. While a number of studies have independently investigated motivational or performance aspects of social behaviours, few have examined how these aspects relate to each other. By comparing behavioural variation in response to live or video presentations of conspecific females, we analysed how variation in the motivation to produce courtship song covaries with variation in performance aspects of courtship song in male zebra finches (Taeniopygia guttata). Consistent with previous reports, we observed that male zebra finches were less motivated to produce courtship songs to videos of females than to live presentations of females. However, we found that acoustic features that reflect song performance were indistinguishable between songs produced to videos of females and songs produced to live presentations of females. For example, songs directed at video presentations of females were just as fast and stereotyped as songs directed at live females. These experimental manipulations and correlational analyses reveal a dissociation between motivational and performance aspects of birdsong and suggest a refinement of neural models of song production and control. In addition, they support the efficacy of videos to study both motivational and performance aspects of social behaviours.

scholarly journals Noninvasive Optical Measurements of Dynamic Cerebral Autoregulation by Inducing Oscillatory Cerebral Hemodynamics

2021 ◽  
Vol 12 ◽  
Author(s):  
Thao Pham ◽  
Cristianne Fernandez ◽  
Giles Blaney ◽  
Kristen Tgavalekos ◽  
Angelo Sassaroli ◽  
...  
Keyword(s):  
Phase Difference ◽  
Cerebral Autoregulation ◽  
Healthy Subjects ◽  
Near Infrared ◽  
Function Analysis ◽  
Optical Measurements ◽  
Negative Phase ◽  
Arterial Blood ◽  
Transfer Function Analysis ◽  
Highly Correlated

Objective: Cerebral autoregulation limits the variability of cerebral blood flow (CBF) in the presence of systemic arterial blood pressure (ABP) changes. Monitoring cerebral autoregulation is important in the Neurocritical Care Unit (NCCU) to assess cerebral health. Here, our goal is to identify optimal frequency-domain near-infrared spectroscopy (FD-NIRS) parameters and apply a hemodynamic model of coherent hemodynamics spectroscopy (CHS) to assess cerebral autoregulation in healthy adult subjects and NCCU patients.Methods: In five healthy subjects and three NCCU patients, ABP oscillations at a frequency around 0.065 Hz were induced by cyclic inflation-deflation of pneumatic thigh cuffs. Transfer function analysis based on wavelet transform was performed to measure dynamic relationships between ABP and oscillations in oxy- (O), deoxy- (D), and total- (T) hemoglobin concentrations measured with different FD-NIRS methods. In healthy subjects, we also obtained the dynamic CBF-ABP relationship by using FD-NIRS measurements and the CHS model. In healthy subjects, an interval of hypercapnia was performed to induce cerebral autoregulation impairment. In NCCU patients, the optical measurements of autoregulation were linked to individual clinical diagnoses.Results: In healthy subjects, hypercapnia leads to a more negative phase difference of both O and D oscillations vs. ABP oscillations, which are consistent across different FD-NIRS methods and are highly correlated with a more negative phase difference CBF vs. ABP. In the NCCU, a less negative phase difference of D vs. ABP was observed in one patient as compared to two others, indicating a better autoregulation in that patient.Conclusions: Non-invasive optical measurements of induced phase difference between D and ABP show the strongest sensitivity to cerebral autoregulation. The results from healthy subjects also show that the CHS model, in combination with FD-NIRS, can be applied to measure the CBF-ABP dynamics for a better direct measurement of cerebral autoregulation.

scholarly journals Slave System Dimension Expansion Approach for Robust Synchronization of Chaotic Systems with Unknown Phase Difference

2011 ◽  
Vol 2011 ◽  
pp. 1-9
Author(s):  
Huanhuan Mai ◽  
Weiwei Zhang ◽  
Yapeng Zhao
Keyword(s):  
Phase Difference ◽  
Chaotic Systems ◽  
Control Variable ◽  
Coupled Systems ◽  
Slave System ◽  
Flexible Control ◽  
Forcing Term ◽  
Unknown Phase ◽  
Robust Synchronization ◽  
Dimension Expansion

A technique which increased the dimension of slave system is adopted for robust synchronization of chaotic systems with unknown phase difference. The phase difference plays a great role in variation of dynamic behavior of the coupled systems. The phase difference of the sinusoidal forcing term is always assumed to be known in the majority of the existing literature. However, unknown parameter error value has always existed in real problems. This method uses the properties of the triangular function and increases the number of dimensions in the slave system to match the phase of forcing term in the master system. Numerical simulations show that the flexible control variable we first investigated is very important. We expect our results to be of some broader applicabilities.

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