By: Maitreyee Wairagkar Postdoc Research Associate,Biomechatronics Lab,Department of Mechanical Engineering,Imperial College London Email me Brain activity is composed of both oscillatory and broadband arrhythmic components; however, neural correlates of movement are commonly characterised by narrowband oscillatory processes such as event-related desynchronisation (ERD). The complex ongoing scale-free dynamics of the arrhythmic broadband electroencephalography (EEG) remain unexplored. … Continue reading Virtual Poster #25 – Long Range Dependence Dynamics of Broadband EEG Predicts Movement
By: Fernando Antônio Nóbrega Santos, Department of Anatomy and Neurosciences, Vrije University of Amsterdam, Amsterdam UMC, the Netherlands Email me Functional brain networks are often constructed by quantifying correlations between time series of activity of brain regions. Their topological structure includes nodes, edges, triangles, and even higher-dimensional objects. Topological data analysis (TDA) is the emerging … Continue reading Virtual Poster #24 – Topological Phase Transitions in functional Brain Networks
By: Giuseppe Vitiello, Dipartimento di Fisica "E.R.Caianiello", Università di Salerno, 84084 Fisciano (Salerno), Italy We discusses brain visual experiences in conditions of low degree of openness of the brain toward the environment, for example, while dreaming, during meditation, or in non-ordinary brain activity states such as under the effects of psychoactive substances, in the state … Continue reading Virtual Poster #23 – Criticality and Chaotic Trajectories in Brain-Mind Visual Experiences
by Bram Alexander Siebert, University of Limerick Email me Modularity plays a significant role in the formation of patterns of activity onbrain networks due to the small spectral gap of modular networks. As a byproduct, themodularity leads to the formation of macroscopic patterns, where the amount of activatorand inhibitor on nodes in the same modules … Continue reading Virtual Poster #22 – The role of modularity in the formation of macroscopic patterns on modular networks
by Daniele Marinazzo, Gent University, Belgium Email me Implementing the Ising model on a 2D lattice, we showed that the joint synergistic information shared by two variables on a target one peaks before the transition to an ordered state (critical point). Here we implemented the same model on individual structural connectomes, to answer these questions:Does … Continue reading Virtual Poster #21 – Synergistic information in a dynamical model implemented on the human structural connectome reveals spatially distinct associations with age
by Amin Safaeesirat, Saman Moghimi-Araghi (Physics Department, Sharif University of Technology). The presence of both critical behavior and oscillating patterns in brain dynamics is a very interesting issue. In this work, we have considered a model for a neuron population, where each neuron is modeled by an over-damped rotator. We have found that in the space of external parameters, there exist some regions that system shows synchronization. Interestingly, just at the transition point, the avalanche statistics show a power-law behavior. Also, in the case of small systems, the (partially) synchronization and power-law behavior can happen at the same time.
By Adrian Ponce Alvarez et al. (Pompeu Fabra University, Barcelona, Spain) How does the local collective activity of brain regions determine the global brain state related to consciousness? To answer this question, we modeled loss of consciousness using anesthetic agents in macaque monkeys while recording the collective activity of brain regions using functional MRI. We … Continue reading Virtual poster #19 – Macroscopic quantities of collective brain activity during wakefulness and anesthesia
By Nicola Pedreschi, Alain Barrat, Demian Battaglia et al. Neural computation is associated with the emergence, reconfiguration, and dissolution of cell assemblies in the context of varying oscillatory states. Here, we describe the complex spatiotemporal dynamics of cell assemblies through temporal network formalism. We use a sliding window approach to extract sequences of networks of information sharing among single units in hippocampus and entorhinal cortex during anesthesia and study how global and node-wise functional connectivity properties evolve through time and as a function of changing global brain state (theta vs. slow-wave oscillations)...
by Giorgio Nicoletti, Samir Suweis, Amos Maritan. We present a systematic study to test a recently introduced phenomenological renormalization group, proposed to coarse-grain data of neural activity from their correlation matrix. The approach allows, at least in principle, to establish whether the collective behavior of the network of spiking neurons is described by a non-Gaussian critical fixed point. We test this renormalization procedure in a variety of models focusing in particular on the contact process...
By Saeed Mahdisoltani & Saman Moghimi-Araghi. It is known that various distribution functions of neuronal activities in, and connectivities between different parts of, the brain follow power-law forms, suggesting that it is a self-oragnized critical (SOC) system. Here we introduce a sandpile-type network with dynamical changes in the links modeled by Hebb's rule and spike-timing-dependent-plasticity (STDP) mechanism, and we also allow new links to be created by the most active nodes and the weak links to be eliminated during a `pruning' process. We show that these rules drive both the dynamics of the nodes and the structure of the network towards a scale-free steady state; the avalanche size distribution is given by a power-law with exponent 1.5, while the statistics of the links follows a scaling law with exponent 1, resembling the distribution of weights observed in the Human Connectome Project (HCP).