scholarly journals Spectral power differences in the brain activity of growth-restricted and normal fetuses

2012 ◽  
Vol 88 (6) ◽  
pp. 451-454 ◽  
Author(s):  
Hari Eswaran ◽  
Rathinaswamy B. Govindan ◽  
Naim I. Haddad ◽  
Eric R. Siegel ◽  
Hubert T. Preissl ◽  
...  
Keyword(s):  
Spectral Power ◽  
Brain Activity ◽  
The Brain

scholarly journals Formation of attention in men and women during tasks performance with high cognitive load

2017 ◽  
Vol 23 (2) ◽  
pp. 9-14
Author(s):  
M. Bondarenko ◽  
O. Bondarenko ◽  
V. Kravchenko ◽  
M. Makarchuk
Keyword(s):  
Cognitive Load ◽  
Theta Rhythm ◽  
Alpha Rhythm ◽  
Spectral Power ◽  
Brain Activity ◽  
Visual Content ◽  
Voluntary Attention ◽  
Dominant Eye ◽  
The Brain ◽  
Theta Range

The differences in brain mechanisms that underlie the switch between involuntary and voluntary attention associated with gender were investigated. We compared reaction time, the number of errors and the electrical activity of the brain during the Emotional Stroop test on the background of visual content that contained affective images when presenting stimuli through a dominant and non-dominant eye in 20 men and 20 women. The model of significant cognitive load was created, when it is quite difficult to correctly respond to the relevant characteristics of the stimulus. Different patterns of brain activity have been found: in women, this task is accompanied by an increase in spectral power in the theta range of the predominantly left hemisphere; in men, the power of alpha rhythm in the parietal-occipital associative cortex decreases with the local increase of theta rhythm in the posterior-frontal areas and beta-rhythm in left prefrontal zone. Under the conditions of high cognitive load created by the distracting visual content and the perception of visual stimuli through the non-dominant eye, the brain mechanisms of voluntary attention provide a more thorough analysis of the relevant stimuli in women that is seen in accurate responses over a longer period in comparison with men.

scholarly journals Fractal dimension and neurotoxicity in rats intoxicated by aluminium

2015 ◽  
Vol 69 (1-2) ◽  
pp. 21-29
Author(s):  
Ljiljana Martac
Keyword(s):  
Animal Model ◽  
Spectral Power ◽  
Brain Activity ◽  
Aluminium Toxicity ◽  
Experimental Models ◽  
Mathematical Methods ◽  
And Function ◽  
The Brain

We used animal model of neurotoxicity in rats, which provided the possibility of studying biological pathophysiological phenomena in vivo and afterwards in vitro conditions. The analysis of electrocortical brain activity using mathematical methods can describe the changes induced by aluminum intoxication in rat as an animal model. In physiological and pathophysiological conditions, on experimental models, mechanisms related to changes in behavior, plasticity and accumulation of aluminum in nervous tissue of the rat brain were observed. Animal models of rats used in the experiments described changes in the group of neuronal activity in the brain of rats in different modes of intoxication aluminum. This study describes ECoG activity in the brain of rats under anesthesia in both the control and aluminum treated animals. Fractal and spectral analysis was used to present qualitative and quantitative changes in the conditions of neurotoxicity. Changes in neurotransmission, as well as the structure and function of the neural network are connected to the molecular-physiological mechanisms of neurotoxicity. Aluminium toxicity was monitored through changes in glutamatergic activity and calcium channel activity. By spectrum analysis neurotoxicity was described through changes in spectral power in the corresponding frequency ranges. By comparing the FD of intoxicated and control individuals there was obtained the range of the change in correlation with the corresponding pathophysiological conditions of intoxication. The shange in FD might be an indication of neurotoxicity.

scholarly journals Effects of Red and White Ginseng Preparations on Electrical Activity of the Brain in Elderly Subjects: A Randomized, Double-Blind, Placebo-Controlled, Three-Armed Cross-Over Study

2021 ◽  
Vol 14 (3) ◽  
pp. 182
Author(s):  
Wilfried Dimpfel ◽  
Pierre-Antoine Mariage ◽  
Alexander G. Panossian
Keyword(s):  
Electrical Activity ◽  
Spectral Power ◽  
Brain Activity ◽  
Brain Regions ◽  
Elderly Subjects ◽  
Strong Impact ◽  
Double Blind ◽  
Double Blind Placebo ◽  
White Ginseng ◽  
The Brain

Background: Recently, the superior efficacy of hydroponically cultivated red ginseng preparation HRG80® compared to wild growing white ginseng (WG) in preventing stress-induced symptoms related to the daily work situation of healthy subjects was reported. The aim of this study was to compare the effects of HRG80®, WG, and placebo on the electrical activity in the brain of elderly human subjects during relaxation and mental challenges. Methods: Changes in the electroencephalogram (EEG) frequency ranges of 17 different brain regions were measured after single and repeated administration of HRG80®, WG, and placebo across a four-week randomized, double-blind, placebo-controlled three-armed cross-over trial. Results: Both red and white ginseng preparations had a strong impact on brain activity, with different effects on various brain regions depending on the mental load during relaxation and cognitive tasks associated with memory, attention, and mental performance. Both ginseng preparations exhibited significant effects on spectral powers compared to placebo, reflecting an activating action. The spectral changes in the quantitative EEG induced by HRG80® indicated an improvement in mood as well as calming effects, evidenced by the modulation of β2 waves, representing changes in GABA-ergic neurotransmission. HRG80® attenuated δ/θ powers during relaxation, suggesting the potential improvement of pathologically enhanced spectral power in aging. Conclusion: The results of this study suggest that both hydroponically cultivated red and wild growing white ginseng have similar beneficial effects on the cognitive functions of elderly subjects, as reflected by electric brain activity, but their modes of action on the brain are different.

scholarly journals Non-Parametric Evaluation Methods of the Brain Activity of a Bottlenose Dolphin during an Assisted Therapy

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 417
Author(s):  
Jesús Jaime Moreno Escobar ◽  
Oswaldo Morales Matamoros ◽  
Erika Yolanda Aguilar del Villar ◽  
Ricardo Tejeida Padilla ◽  
Ixchel Lina Reyes ◽  
...  
Keyword(s):  
Bottlenose Dolphin ◽  
Single Channel ◽  
Spectral Power ◽  
Brain Activity ◽  
Stress Relief ◽  
Alternative Therapies ◽  
Neuronal Signal ◽  
Usual Behavior ◽  
Anxiety Levels ◽  
The Brain

Dolphin-Assisted Therapies (DAT) are alternative therapies aimed to reduce anxiety levels, stress relief and physical benefits. This paper is focused on measuring and analyzing dolphins brain activity when DAT is taking place in order to identify if there is any differences in female dolphin’s neuronal signal when it is interacting with control or intervention subjects, performing our research in Delfiniti, Ixtapa, Mexico facilities. We designed a wireless and portable electroencephalographic single-channel signal capture sensor to acquire and monitor the brain activity of a female bottle-nose dolphin. This EEG sensor was able to show that dolphin activity at rest is characterized by high spectral power at slow-frequencies bands. When the dolphin participated in DAT, a 23.53% increment in the 12–30 Hz frequency band was observed, but this only occurred for patients with some disease or disorder, given that 0.5–4 Hz band keeps it at 17.91% when there is a control patient. Regarding the fractal or Self-Affine Analysis, we found for all samples studied that at the beginning the dolphin’s brain activity behaved as a self-affine fractal described by a power-law until the fluctuations of voltage reached the crossovers, and after the crossovers these fluctuations left this scaling behavior. Hence, our findings validate the hypothesis that the participation in a DAT of a Patient with a certain disease or disorder modifies the usual behavior of a female bottle-nose dolphin.

Complexity Measures of Brain Electrophysiological Activity

2010 ◽  
Vol 24 (2) ◽  
pp. 131-135 ◽  
Author(s):  
Włodzimierz Klonowski ◽  
Pawel Stepien ◽  
Robert Stepien
Keyword(s):  
Brain Activity ◽  
Deterministic Chaos ◽  
Epileptic Seizures ◽  
Eeg Signal ◽  
Eeg Signals ◽  
Complexity Measures ◽  
Electrophysiological Activity ◽  
Signal Complexity ◽  
Physiological Sleep ◽  
The Brain

Over 20 years ago, Watt and Hameroff (1987 ) suggested that consciousness may be described as a manifestation of deterministic chaos in the brain/mind. To analyze EEG-signal complexity, we used Higuchi’s fractal dimension in time domain and symbolic analysis methods. Our results of analysis of EEG-signals under anesthesia, during physiological sleep, and during epileptic seizures lead to a conclusion similar to that of Watt and Hameroff: Brain activity, measured by complexity of the EEG-signal, diminishes (becomes less chaotic) when consciousness is being “switched off”. So, consciousness may be described as a manifestation of deterministic chaos in the brain/mind.

Relation Between Level of Prefrontal Activity and Subject's Performance

1999 ◽  
Vol 13 (2) ◽  
pp. 117-125 ◽  
Author(s):  
Laurence Casini ◽  
Françoise Macar ◽  
Marie-Hélène Giard
Keyword(s):  
Brain Activity ◽  
Sensory Information ◽  
Practice Phase ◽  
Trained Subjects ◽  
Anagram Task ◽  
Economic Information ◽  
Long Duration ◽  
Level Of Activity ◽  
The Brain ◽  
Processing Mechanism

Abstract The experiment reported here was aimed at determining whether the level of brain activity can be related to performance in trained subjects. Two tasks were compared: a temporal and a linguistic task. An array of four letters appeared on a screen. In the temporal task, subjects had to decide whether the letters remained on the screen for a short or a long duration as learned in a practice phase. In the linguistic task, they had to determine whether the four letters could form a word or not (anagram task). These tasks allowed us to compare the level of brain activity obtained in correct and incorrect responses. The current density measures recorded over prefrontal areas showed a relationship between the performance and the level of activity in the temporal task only. The level of activity obtained with correct responses was lower than that obtained with incorrect responses. This suggests that a good temporal performance could be the result of an efficacious, but economic, information-processing mechanism in the brain. In addition, the absence of this relation in the anagram task results in the question of whether this relation is specific to the processing of sensory information only.

Automated System for Epileptic Seizures Prediction based on Multi-Channel Recordings of Electrical Brain Activity

2018 ◽  
pp. 115-122 ◽  
Author(s):  
V. A. Maksimenko ◽  
A. A. Harchenko ◽  
A. Lüttjohann
Keyword(s):  
Epileptic Seizure ◽  
Brain Activity ◽  
Epileptic Seizures ◽  
Automated System ◽  
Brain Computer Interfaces ◽  
Electrical Brain Activity ◽  
Computer Interfaces ◽  
Prediction And Prevention ◽  
The Brain

Introduction: Now the great interest in studying the brain activity based on detection of oscillatory patterns on the recorded data of electrical neuronal activity (electroencephalograms) is associated with the possibility of developing brain-computer interfaces. Braincomputer interfaces are based on the real-time detection of characteristic patterns on electroencephalograms and their transformation  into commands for controlling external devices. One of the important areas of the brain-computer interfaces application is the control of the pathological activity of the brain. This is in demand for epilepsy patients, who do not respond to drug treatment.Purpose: A technique for detecting the characteristic patterns of neural activity preceding the occurrence of epileptic seizures.Results:Using multi-channel electroencephalograms, we consider the dynamics of thalamo-cortical brain network, preceded the occurrence of an epileptic seizure. We have developed technique which allows to predict the occurrence of an epileptic seizure. The technique has been implemented in a brain-computer interface, which has been tested in-vivo on the animal model of absence epilepsy.Practical relevance:The results of our study demonstrate the possibility of epileptic seizures prediction based on multichannel electroencephalograms. The obtained results can be used in the development of neurointerfaces for the prediction and prevention of seizures of various types of epilepsy in humans. 

scholarly journals An Analysis of the External Validity of EEG Spectral Power in an Uncontrolled Outdoor Environment during Default and Complex Neurocognitive States

2021 ◽  
Vol 11 (3) ◽  
pp. 330
Author(s):  
Dalton J. Edwards ◽  
Logan T. Trujillo
Keyword(s):  
External Validity ◽  
Spectral Power ◽  
Brain Activity ◽  
Outdoor Environment ◽  
Oscillatory Activity ◽  
Brain State ◽  
Beta Band ◽  
Eeg Spectral Power ◽  
Eeg Power ◽  
Human Participants

Traditionally, quantitative electroencephalography (QEEG) studies collect data within controlled laboratory environments that limit the external validity of scientific conclusions. To probe these validity limits, we used a mobile EEG system to record electrophysiological signals from human participants while they were located within a controlled laboratory environment and an uncontrolled outdoor environment exhibiting several moderate background influences. Participants performed two tasks during these recordings, one engaging brain activity related to several complex cognitive functions (number sense, attention, memory, executive function) and the other engaging two default brain states. We computed EEG spectral power over three frequency bands (theta: 4–7 Hz, alpha: 8–13 Hz, low beta: 14–20 Hz) where EEG oscillatory activity is known to correlate with the neurocognitive states engaged by these tasks. Null hypothesis significance testing yielded significant EEG power effects typical of the neurocognitive states engaged by each task, but only a beta-band power difference between the two background recording environments during the default brain state. Bayesian analysis showed that the remaining environment null effects were unlikely to reflect measurement insensitivities. This overall pattern of results supports the external validity of laboratory EEG power findings for complex and default neurocognitive states engaged within moderately uncontrolled environments.

scholarly journals Conditional Entropy: A Potential Digital Marker for Stress

Entropy ◽  
2021 ◽  
Vol 23 (3) ◽  
pp. 286
Author(s):  
Soheil Keshmiri
Keyword(s):  
Resting State ◽  
Nearest Neighbor ◽  
Brain Activity ◽  
Solution Concept ◽  
Conditional Entropy ◽  
K Nearest Neighbor ◽  
Brain Response ◽  
Substantial Progress ◽  
Eeg Recordings ◽  
The Brain

Recent decades have witnessed a substantial progress in the utilization of brain activity for the identification of stress digital markers. In particular, the success of entropic measures for this purpose is very appealing, considering (1) their suitability for capturing both linear and non-linear characteristics of brain activity recordings and (2) their direct association with the brain signal variability. These findings rely on external stimuli to induce the brain stress response. On the other hand, research suggests that the use of different types of experimentally induced psychological and physical stressors could potentially yield differential impacts on the brain response to stress and therefore should be dissociated from more general patterns. The present study takes a step toward addressing this issue by introducing conditional entropy (CE) as a potential electroencephalography (EEG)-based resting-state digital marker of stress. For this purpose, we use the resting-state multi-channel EEG recordings of 20 individuals whose responses to stress-related questionnaires show significantly higher and lower level of stress. Through the application of representational similarity analysis (RSA) and K-nearest-neighbor (KNN) classification, we verify the potential that the use of CE can offer to the solution concept of finding an effective digital marker for stress.

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