scholarly journals Probing cortical and sub-cortical contributions to instruction-based learning: Regional specialisation and global network dynamics

NeuroImage ◽  
2019 ◽  
Vol 192 ◽  
pp. 88-100 ◽  
Author(s):  
Adam Hampshire ◽  
Richard E. Daws ◽  
Ines Das Neves ◽  
Eyal Soreq ◽  
Stefano Sandrone ◽  
...  
Keyword(s):  
Network Dynamics ◽  
Global Network ◽  
Regional Specialisation

scholarly journals Stabilization of Brain Network Dynamics during Childhood and Adolescence is Associated with Gene Expressions

2021 ◽  
Author(s):  
Tianyuan Lei ◽  
Xuhong Liao ◽  
Xiaodan Chen ◽  
Tengda Zhao ◽  
Yuehua Xu ◽  
...  
Keyword(s):  
Large Scale ◽  
Expression Profiles ◽  
Brain Networks ◽  
Network Dynamics ◽  
Brain Network ◽  
Global Network ◽  
Association Cortex ◽  
Childhood And Adolescence ◽  
Gene Expressions ◽  
Age Related

AbstractFunctional brain networks require dynamic reconfiguration to support flexible cognitive function. However, the developmental principles shaping brain network dynamics remain poorly understood. Here, we report the longitudinal development of large-scale brain network dynamics during childhood and adolescence, and its connection with gene expression profiles. Using a multilayer network model, we show the temporally varying modular architecture of child brain networks, with higher network switching primarily in the association cortex and lower switching in the primary regions. This topographical profile exhibits progressive maturation, which manifests as reduced modular dynamics, particularly in the transmodal (e.g., default-mode and frontoparietal) and sensorimotor regions. These developmental refinements mediate age-related enhancements of global network segregation and are linked with the expression profiles of genes associated with the enrichment of ion transport and nucleobase-containing compound transport. These results highlight a progressive stabilization of brain dynamics, which expand our understanding of the neural mechanisms that underlie cognitive development.

scholarly journals Charge transport network dynamics in molecular aggregates

2016 ◽  
Vol 113 (31) ◽  
pp. 8595-8600 ◽  
Author(s):  
Nicholas E. Jackson ◽  
Lin X. Chen ◽  
Mark A. Ratner
Keyword(s):  
Charge Transport ◽  
Disordered Systems ◽  
Network Dynamics ◽  
Network Connectivity ◽  
Global Network ◽  
Static Charge ◽  
Transport Networks ◽  
Carrier Lifetimes ◽  
Type Molecule ◽  
Transfer Integral

Due to the nonperiodic nature of charge transport in disordered systems, generating insight into static charge transport networks, as well as analyzing the network dynamics, can be challenging. Here, we apply time-dependent network analysis to scrutinize the charge transport networks of two representative molecular semiconductors: a rigid n-type molecule, perylenediimide, and a flexible p-type molecule, bBDT(TDPP)2. Simulations reveal the relevant timescale for local transfer integral decorrelation to be ∼100 fs, which is shown to be faster than that of a crystalline morphology of the same molecule. Using a simple graph metric, global network changes are observed over timescales competitive with charge carrier lifetimes. These insights demonstrate that static charge transport networks are qualitatively inadequate, whereas average networks often overestimate network connectivity. Finally, a simple methodology for tracking dynamic charge transport properties is proposed.

scholarly journals Coherence Resonance in Random Erdös-Rényi Neural Networks: Mean-Field Theory

2021 ◽  
Vol 7 ◽  
Author(s):  
A. Hutt ◽  
T. Wahl ◽  
N. Voges ◽  
Jo Hausmann ◽  
J. Lefebvre
Keyword(s):  
Additive Noise ◽  
Mean Field Theory ◽  
Network Dynamics ◽  
Mean Field ◽  
Power Spectra ◽  
Global Network ◽  
Coherence Resonance ◽  
Field Representation ◽  
Excitatory Neurons ◽  
The Stability

Additive noise is known to tune the stability of nonlinear systems. Using a network of two randomly connected interacting excitatory and inhibitory neural populations driven by additive noise, we derive a closed mean-field representation that captures the global network dynamics. Building on the spectral properties of Erdös-Rényi networks, mean-field dynamics are obtained via a projection of the network dynamics onto the random network’s principal eigenmode. We consider Gaussian zero-mean and Poisson-like noise stimuli to excitatory neurons and show that these noise types induce coherence resonance. Specifically, the stochastic stimulation induces coherent stochastic oscillations in the γ-frequency range at intermediate noise intensity. We further show that this is valid for both global stimulation and partial stimulation, i.e. whenever a subset of excitatory neurons is stimulated only. The mean-field dynamics exposes the coherence resonance dynamics in the γ-range by a transition from a stable non-oscillatory equilibrium to an oscillatory equilibrium via a saddle-node bifurcation. We evaluate the transition between non-coherent and coherent state by various power spectra, Spike Field Coherence and information-theoretic measures.

scholarly journals Comparison of Combinatorial Signatures of Global Network Dynamics Generated by Two Classes of ODE Models

2019 ◽  
Vol 18 (1) ◽  
pp. 418-457 ◽  
Author(s):  
Peter Crawford-Kahrl ◽  
Bree Cummins ◽  
Tomas Gedeon
Keyword(s):  
Network Dynamics ◽  
Global Network ◽  
Ode Models

scholarly journals Flexible coordinator and switcher hubs for adaptive task control

2019 ◽  
Author(s):  
Carrisa V Cocuzza ◽  
Takuya Ito ◽  
Douglas Schultz ◽  
Danielle S Bassett ◽  
Michael W Cole
Keyword(s):  
Cognitive Control ◽  
Large Scale ◽  
Network Dynamics ◽  
Mental Illnesses ◽  
Global Network ◽  
Connectivity Pattern ◽  
Dependent Manner ◽  
Control Networks ◽  
Processing Resources ◽  
Network Properties

AbstractFunctional connectivity studies have identified at least two large-scale neural systems that constitute cognitive control networks – the frontoparietal network (FPN) and cingulo-opercular network (CON). Control networks are thought to support goal-directed cognition and behavior. It was previously shown that the FPN flexibly shifts its global connectivity pattern according to task goal, consistent with a “flexible hub” mechanism for cognitive control. Our aim was to build on this finding to develop a functional cartography (a multi-metric profile) of control networks in terms of dynamic network properties. We quantified network properties in (male and female) humans using a high-control-demand cognitive paradigm involving switching among 64 task sets. We hypothesized that cognitive control is enacted by the FPN and CON via distinct but complementary roles reflected in network dynamics. Consistent with a flexible “coordinator” mechanism, FPN connections were varied across tasks, while maintaining within-network connectivity to aid cross-region coordination. Consistent with a flexible “switcher” mechanism, CON regions switched to other networks in a task-dependent manner, driven primarily by reduced within-network connections to other CON regions. This pattern of results suggests FPN acts as a dynamic, global coordinator of goal-relevant information, while CON transiently disbands to lend processing resources to other goal-relevant networks. This cartography of network dynamics reveals a dissociation between two prominent cognitive control networks, suggesting complementary mechanisms underlying goal-directed cognition.Significance StatementCognitive control supports a variety of behaviors requiring flexible cognition, such as rapidly switching between tasks. Furthermore, cognitive control is negatively impacted in a variety of mental illnesses. We used tools from network science to characterize the implementation of cognitive control by large-scale brain systems. This revealed that two systems – the frontoparietal (FPN) and cingulo-opercular (CON) networks – have distinct but complementary roles in controlling global network reconfigurations. The FPN exhibited properties of a flexible coordinator (orchestrating task changes), while CON acted as a flexible switcher (switching specific regions to other systems to lend processing resources). These findings reveal an underlying distinction in cognitive processes that may be applicable to clinical, educational, and machine learning work targeting cognitive flexibility.

Indymedia (r)evolution: The global network & rise of one Indymedia center

2003 ◽  
Author(s):  
S. Meinrath ◽  
M. Lehman ◽  
T. Steinlage ◽  
B. Hagy
Keyword(s):  
Global Network

A Survey on Internet of Things : Applications and Layered Wise Security Issues

2019 ◽  
pp. 171-180
Author(s):  
Uppuluri Sirisha ◽  
G. Lakshme Eswari
Keyword(s):  
Quality Of Life ◽  
Internet Of Things ◽  
Security And Privacy ◽  
Global Network ◽  
Business Growth ◽  
Paper Briefly ◽  
Smart Meters ◽  
Security Issues ◽  
Data Points

This paper briefly introduces Internet of Things(IOT) as a intellectual connectivity among the physical objects or devices which are gaining massive increase in the fields like efficiency, quality of life and business growth. IOT is a global network which is interconnecting around 46 million smart meters in U.S. alone with 1.1 billion data points per day[1]. The total installation base of IOT connecting devices would increase to 75.44 billion globally by 2025 with a increase in growth in business, productivity, government efficiency, lifestyle, etc., This paper familiarizes the serious concern such as effective security and privacy to ensure exact and accurate confidentiality, integrity, authentication access control among the devices.

Sign in / Sign up

Export Citation Format

Share Document