A combinatorial view of stochastic processes: White noise

 Alvaro Diaz-Ruelas

Chaos 32, 123136 (2022)

The incorporation of stochastic ingredients in models describing phenomena in all disciplines is now a standard in scientific practice. White noise is one of the most important of such stochastic ingredients. Although tools for identifying white and other types of noise exist,1,2 there is a permanent demand for reliable and robust statistical methods for analyzing data in order to distinguish noise and filter it from signals in experiments. Or in hypothesis tests, for assessing the plausibility of the outcome of an experiment being the result of randomness and not a significant, controllable effect. Due to its ubiquity in experiments and its mathematical simplicity, white noise is very often the most convenient stochastic component that adds realism to a dynamic model, commonly regarded as the noise polluting observations. It can be continuous or discrete both in time and in distribution, so it can be applied to many scenarios. It is a stationary and independent and identically distributed process, all relatively simple properties for a stochastic process. Here, we present a combinatorial perspective to study white noise inspired in the concept of ordinal patterns.

Read the full article at: aip.scitation.org

Theoretical foundations of studying criticality in the brain

Yang Tian, Zeren Tan, Hedong Hou, Guoqi Li, Aohua Cheng, Yike Qiu, Kangyu Weng, Chun Chen, Pei Sun

Network Neuroscience (2022) 6 (4): 1148–1185.

The brain criticality hypothesis is one of the most focused and controversial topics in neuroscience and biophysics. This research develops a unified framework to reformulate the physics theories of four basic types of brain criticality, ordinary criticality (OC), quasi-criticality (qC), self-organized criticality (SOC), and self-organized quasi-criticality (SOqC), into more accessible and neuroscience-related forms. For the statistic techniques used to validate the brain criticality hypothesis, we also present comprehensive explanations of them, summarize their error-prone details, and suggest possible solutions. This framework may help resolve potential controversies in studying the brain criticality hypothesis, especially those arising from the misconceptions about the theoretical foundations of brain criticality.

Read the full article at: direct.mit.edu

Evidence of Critical Dynamics in Movements of Bees inside a Hive

Ivan Shpurov and Tom Froese

Entropy 2022, 24(12), 1840

Social insects such as honey bees exhibit complex behavioral patterns, and their distributed behavioral coordination enables decision-making at the colony level. It has, therefore, been proposed that a high-level description of their collective behavior might share commonalities with the dynamics of neural processes in brains. Here, we investigated this proposal by focusing on the possibility that brains are poised at the edge of a critical phase transition and that such a state is enabling increased computational power and adaptability. We applied mathematical tools developed in computational neuroscience to a dataset of bee movement trajectories that were recorded within the hive during the course of many days. We found that certain characteristics of the activity of the bee hive system are consistent with the Ising model when it operates at a critical temperature, and that the system’s behavioral dynamics share features with the human brain in the resting state.

Read the full article at: www.mdpi.com

Systems At Play: The Self-Organising Symposium on Self-Organisation (SOSOSO). Brussels, Feb. 15-18 2023

The Center Leo Apostel for Transdisciplinary Studies (CLEA) at the Vrije Universiteit Brussel (VUB) organises its first international artscience conference: ‘Systems At Play: A Self-Organising Symposium on Self-Organisation’ taking place in Brussels from February 15th until 18th, 2023. 

The ‘Systems at Play’ symposium starts from the understanding that art and science are mutually beneficial means of perception and insight creation. It thus provides a transdisciplinary contact zone for artists and scientists to meet, exchange, think, share, take time, and, ultimately, play together.

Then, what shall we talk and play about? Well, it’s up to you where it ends up, but our starting points are the ideas of ‘emergence’, ‘self-organisation’, and ‘goal-directedness’.

As far as goals go, the symposium invites you to tackle creative challenges collectively. During the symposium, participating artists and scientists will together create ‘embodied models of emergence’ in the form of live games, scores, presentations, conversations or small algorithmic performances. We will offer inputs to this process in the form of presentations, talks and workshops during the day; as well as an evening programme of immersive and interactive performances and film screenings. 

More at: clea.research.vub.be