Topics

Fractal dimension of cortical functional connectivity networks & severity of disorders of consciousness.

07:00 EST 13th February 2020 | BioPortfolio

Summary of "Fractal dimension of cortical functional connectivity networks & severity of disorders of consciousness."

Recent evidence suggests that the quantity and quality of conscious experience may be a function of the complexity of activity in the brain and that consciousness emerges in a critical zone between low and high-entropy states. We propose fractal shapes as a measure of proximity to this critical point, as fractal dimension encodes information about complexity beyond simple entropy or randomness, and fractal structures are known to emerge in systems nearing a critical point. To validate this, we tested several measures of fractal dimension on the brain activity from healthy volunteers and patients with disorders of consciousness of varying severity. We used a Compact Box Burning algorithm to compute the fractal dimension of cortical functional connectivity networks as well as computing the fractal dimension of the associated adjacency matrices using a 2D box-counting algorithm. To test whether brain activity is fractal in time as well as space, we used the Higuchi temporal fractal dimension on BOLD time-series. We found significant decreases in the fractal dimension between healthy volunteers (n = 15), patients in a minimally conscious state (n = 10), and patients in a vegetative state (n = 8), regardless of the mechanism of injury. We also found significant decreases in adjacency matrix fractal dimension and Higuchi temporal fractal dimension, which correlated with decreasing level of consciousness. These results suggest that cortical functional connectivity networks display fractal character and that this is associated with level of consciousness in a clinically relevant population, with higher fractal dimensions (i.e. more complex) networks being associated with higher levels of consciousness. This supports the hypothesis that level of consciousness and system complexity are positively associated, and is consistent with previous EEG, MEG, and fMRI studies.

Affiliation

Journal Details

This article was published in the following journal.

Name: PloS one
ISSN: 1932-6203
Pages: e0223812

Links

DeepDyve research library

PubMed Articles [17777 Associated PubMed Articles listed on BioPortfolio]

Genetic and environmental influences on functional connectivity within and between canonical cortical resting-state networks throughout adolescent development in boys and girls.

The human brain is active during rest and hierarchically organized into intrinsic functional networks. These functional networks are largely established early in development, with reports of a shift f...

Increased neural connectivity between the hypothalamus and cortical resting-state functional networks in chronic migraine.

The findings of resting-state functional MRI studies have suggested that abnormal functional integration between interconnected cortical networks characterises the brain of patients with migraine. The...

Patterns of Cerebellar Connectivity with Intrinsic Connectivity Networks in Autism Spectrum Disorders.

There is growing evidence of altered connectivity in autism spectrum disorders (ASD) between the cerebellum and cortex. Three intrinsic connectivity networks (ICNs) are especially important to cogniti...

Unstable wakefulness during resting-state fMRI and its associations with network connectivity and affective psychopathology in young adults.

Drifts between wakefulness and sleep are common during resting state functional MRI (rsfMRI). Among healthy adults, within-scanner sleep can impact functional connectivity of default mode (DMN), task-...

Cortical Connectivity Moderators of Antidepressant vs Placebo Treatment Response in Major Depressive Disorder: Secondary Analysis of a Randomized Clinical Trial.

Despite the widespread awareness of functional magnetic resonance imaging findings suggesting a role for cortical connectivity networks in treatment selection for major depressive disorder, its clinic...

Clinical Trials [9766 Associated Clinical Trials listed on BioPortfolio]

Cognition and Functional Connectivity After Elective Treatment of Brain Aneurysms

The aim of this proposal is to investigate the effects of uneventful microsurgical and endovascular treatment of unruptured saccular non-giant anterior communicating artery [ACoA] aneurysm...

TMS Modulation of Insula-related Brain Networks.02

The purpose of this study is to investigate the modulatory effects of repetitive transcranial magnetic stimulation (rTMS) on functional connectivity with the insula. Functional connectivit...

TMS Modulation of Insula-related Brain Networks

The purpose of this study is to investigate the modulatory effects of repetitive transcranial magnetic stimulation (rTMS) on functional connectivity with the insula. Functional connectivit...

Resting-state Functional Connectivity Throughout a Course of iTBS in Major Depression

This study aims to investigate changes in functional connectivity over a four week treatment course with intermittent theta burst stimulation (iTBS) in patients with major depressive disor...

Resting-State Neural Connectivity in Patients With Subjective Tinnitus Without Bother

Tinnitus is the occurrence of an auditory sensation without the presence of an acoustic stimulus. Approximately, 50 million people in the United States experience chronic tinnitus and 15 m...

Medical and Biotech [MESH] Definitions

The length of the face determined by the distance of separation of jaws. Occlusal vertical dimension (OVD or VDO) or contact vertical dimension is the lower face height with the teeth in centric occlusion. Rest vertical dimension (VDR) is the lower face height measured from a chin point to a point just below the nose, with the mandible in rest position. (From Jablonski, Dictionary of Dentistry, 1992, p250)

Heterogeneous disorders of cortical malformation characterized by excessive and small fused gyri and shallow sulci of the CORTEX with abnormal cortical lamination. It is considered a malformation secondary to abnormal post-migrational development of the neurons during cerebral cortical development and is associated with EPILEPSY and learning difficulties.

Patterns (real or mathematical) which look similar at different scales, for example the network of airways in the lung which shows similar branching patterns at progressively higher magnifications. Natural fractals are self-similar across a finite range of scales while mathematical fractals are the same across an infinite range. Many natural, including biological, structures are fractal (or fractal-like). Fractals are related to "chaos" (see NONLINEAR DYNAMICS) in that chaotic processes can produce fractal structures in nature, and appropriate representations of chaotic processes usually reveal self-similarity over time.

Cortical malformations secondary to abnormal cortical maturation after CELL MIGRATION in NEUROGENESIS. This group includes injury to the cortex during later stages of cortical development such as POLYMICROGYRIA and focal cortical dysplasias.

Measurable changes in activities in the CEREBRAL CORTEX upon a stimulation. A change in cortical excitability as measured by various techniques (e.g., TRANSCRANIAL MAGNETIC STIMULATION) is associated with brain disorders.

Quick Search


DeepDyve research library

Searches Linking to this Article