Search results for "Information transfer"

Information Decomposition in Multivariate Systems: Definitions, Implementation and Application to Cardiovascular Networks

2016

The continuously growing framework of information dynamics encompasses a set of tools, rooted in information theory and statistical physics, which allow to quantify different aspects of the statistical structure of multivariate processes reflecting the temporal dynamics of complex networks. Building on the most recent developments in this field, this work designs a complete approach to dissect the information carried by the target of a network of multiple interacting systems into the new information produced by the system, the information stored in the system, and the information transferred to it from the other systems; information storage and transfer are then further decomposed into amou…

Synergistic Information Transfer in the Global System of Financial Markets.

2020

Uncovering dynamic information flow between stock market indices has been the topic of several studies which exploited the notion of transfer entropy or Granger causality, its linear version. The output of the transfer entropy approach is a directed weighted graph measuring the information about the future state of each target provided by the knowledge of the state of each driving stock market index. In order to go beyond the pairwise description of the information flow, thus looking at higher order informational circuits, here we apply the partial information decomposition to triplets consisting of a pair of driving markets (belonging to America or Europe) and a target market in Asia. Our …

Causal brain-heart information transfer during visual emotional elicitation in healthy subjects: Preliminary evaluations and future perspectives

2017

Complex heartbeat dynamics is known to reflect subject's emotional state, thanks to numerous links to brain cortical and subcortical regions. Likewise, specific brain regions are deeply involved in vagally-mediated emotional processing and regulation. Nevertheless, although the brain-heart interplay has been studied during visual emotion elicitation, directional interactions have not been investigated so far. To fill this gap, in this study we investigate brain-heart dynamics during emotional elicitation in healthy subjects through measures of Granger causality (GC) between the two physiological systems. Data were gathered from 22 healthy volunteers who underwent pleasant/ unpleasant affect…

Information Dynamics of the Brain, Cardiovascular and Respiratory Network during Different Levels of Mental Stress

2019

In this study, an analysis of brain, cardiovascular and respiratory dynamics was conducted combining information-theoretic measures with the Network Physiology paradigm during different levels of mental stress. Starting from low invasive recordings of electroencephalographic, electrocardiographic, respiratory, and blood volume pulse signals, the dynamical activity of seven physiological systems was probed with one-second time resolution measuring the time series of the &delta

Compensating for instantaneous signal mixing in transfer entropy analysis of neurobiological time series

2013

The transfer entropy (TE) has recently emerged as a nonlinear model-free tool, framed in information theory, to detect directed interactions in coupled processes. Unfortunately, when applied to neurobiological time series TE is biased by signal cross-talk due to volume conduction. To compensate for this bias, in this study we introduce a modified TE measure which accounts for possible instantaneous effects between the analyzed time series. The new measure, denoted as compensated TE (cTE), is tested on simulated time series reproducing conditions typical of neuroscience applications, and on real magnetoencephalographic (MEG) multi-trial data measured during a visuo-tactile cognitive experime…

2020

Whether and to what extent mass media contribute to the acquisition of knowledge depends fundamentally on the senses addressed by a particular medium. However, there is a lack of current research investigating the effectiveness and efficiency of (new) media, like scrollytelling and explainer videos, at conveying information, compared to established formats like text and audio. To fill this research gap, I conducted an experimental online survey (N = 381) with medium as the independent variable (explainer text vs. audio vs. video vs. scrollytelling) and the recall of information as the dependent variable. The subjects were presented with a popular scientific presentation on the environmental…

Information Transfer Between Respiration and Heart Rate During Sleep Apnea

2016

It is well-known that sleep apnea affects the respiration and the heart rate (HR), and studies have shown that the cardiorespiratory coupling is also compromised during obstructive sleep apnea (OSA). Furthermore, the classification of hypopneas is challenging, in particular when only ECG-derived features are used. In this context, this study investigates how different ECG-derived respiratory (EDR) signals resemble the respiratory effort during different types of apneas, and how the amount of information transferred from respiration to HR varies according to the respiratory signal used, real or ECG-derived. ECG and respiratory signals of 10 patients suffering from sleep apnea were analysed, …

Zeitbasiertes Management des akuten Schlaganfalls

1999

Progression in medical research and economic needs require new planning and organization of treatment strategies. This does also apply for stroke treatment: New pathophysiological knowledge, positive results of thrombolytic therapy and the demostrated importance of early treatment at Stroke Units justify that stroke must be regarded as an emergency. Timing is of utmost importance. Time-based management serves as a planning model for a new stroke treatment strategy. The treatment process is divided into three phases: alarming, pre-hospital and in-hospital phase. The effectiveness of each of these phases is influenced by several variables (personnel, technical equipment, course of the disease…

A Framework to Assess the Information Dynamics of Source EEG Activity and Its Application to Epileptic Brain Networks

2020

This study introduces a framework for the information-theoretic analysis of brain functional connectivity performed at the level of electroencephalogram (EEG) sources. The framework combines the use of common spatial patterns to select the EEG components which maximize the variance between two experimental conditions, simultaneous implementation of vector autoregressive modeling (VAR) with independent component analysis to describe the joint source dynamics and their projection to the scalp, and computation of information dynamics measures (information storage, information transfer, statistically significant network links) from the source VAR parameters. The proposed framework was tested on…

Information transfer determined by association of neighbours in European bee-eater (Merops apiaster) colonies

2007

The Information Centre Hypothesis (ICH) and the Two-Strategies Hypothesis (TSH) predict that foraging success is enhanced by information exchanged among individuals within a colony or roost. Nest location within a colony may be critical in this regard, as individuals with abundant, nearby neighbours likely have greater access to information regarding a new food resource than relatively isolated breeders. To determine how the availability of neighbours influences information transfer, we quantified foraging success in a population of European bee-eaters (Merops apiaster) provided with a honey bee (Apis mellifera) hive as a new food resource. To quantify potential information transfer we deve…