Evoked Changes in the Rhythmic Activity of the Brain during Processing of Visually Presented Target, Nontarget, and Unknown Words

The review presents the results of experimental and clinical studies, according to which the absence of circadian melatonin production in pregnant women associated with the pathologies they have (obesity, diabetes mellitus, metabolic syndrome, pregnancy complicated by gestosis and chronic placental insufficiency, etc.) disrupts the genetic process of organizing the rhythmic activity of genes of the suprachiasmatic nuclei of the hypothalamus and melatonin production in the pineal gland of the fetus, leading to dysregulation of metabolic processes in the childs body after birth and programming pathology in following life. The significance of this factor in the pathophysiological mechanisms of catch-up growth during the first months of life determines a new approach to assessing the risk of obesity and necessitates learning the consequences of impaired development of the brain and other functional systems in fetuses that are born earlier than the 26th week of pregnancy and are thereby deprived of maternal melatonin, a key signaling molecule that directs and coordinates the genetic development process, during the most critical period of early ontogenesis.

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The Correlation between the Sites of the Brain for Different Bandwidths of EEG in Interictal Paroxysmal rhythmic Activity: Using Wavelet-crosscorrelation Analysis

Transactions of Japan Society of Kansei Engineering ◽

10.5057/jjske.tjske-d-17-00013 ◽

2017 ◽

Vol 16 (2) ◽

pp. 245-252 ◽

Cited By ~ 1

Author(s):

Kozue YAMAGUCHI ◽

Yoshihiro TSUJI ◽

Steven M.A. CARPELS ◽

Ryoma HAYASHI ◽

Yuji INOGUCHI ◽

...

Keyword(s):

Rhythmic Activity ◽

The Brain

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Quantification of EEG Brain Activity in the Self-Paced Regime

U Porto Journal of Engineering ◽

10.24840/2183-6493_004.001_0001 ◽

2018 ◽

Vol 4 (1) ◽

pp. 1-8

Author(s):

Joana Silva ◽

A. Martins Da Silva ◽

Luís Coelho

Keyword(s):

Brain Activity ◽

Rhythmic Activity ◽

The Self ◽

Automatic Quantification ◽

Frequency Bands ◽

Cerebral Activity ◽

Cognitive Information ◽

Specific Frequency ◽

Electroencephalogram Eeg ◽

The Brain

The processing of motor, sensory and cognitive information by the brain can result in changes of the electroencephalogram (EEG) by Event Related Desynchronization (ERD) or Event Related Synchronization (ERS). The first one concerns a decrease in the amplitude of a rhythmic activity while the second corresponds to its increase. The analysis of these two phenomena in specific frequency bands - alpha (8-13 Hz) and beta (14-30 Hz) - allows the understanding of the cerebral activity. This study focuses on the quantification of cerebral activity by determining the ERD and ERS on the referred band, induced by self-paced movements, by using EEGLAB and MATLAB tools. This was achieved by the creation of a new and automatic quantification algorithm. The results indicate that a greater desynchronization of the signal is accompanied by a decrease in the amplitude of the same. As a conclusion, the cerebral activity varies in terms of synchronization and desynchronization among certain frequency bands in several zones, according to the tasks performed.

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Causal Shannon–Fisher Characterization of Motor/Imagery Movements in EEG

Entropy ◽

10.3390/e20090660 ◽

2018 ◽

Vol 20 (9) ◽

pp. 660 ◽

Cited By ~ 7

Author(s):

Román Baravalle ◽

Osvaldo Rosso ◽

Fernando Montani

Keyword(s):

Large Scale ◽

Rhythmic Activity ◽

Salient Feature ◽

Neural Oscillations ◽

Beta Band ◽

Monitoring Method ◽

Brain Functions ◽

Electroencephalogram Eeg ◽

The Brain

The electroencephalogram (EEG) is an electrophysiological monitoring method that allows us to glimpse the electrical activity of the brain. Neural oscillations patterns are perhaps the best salient feature of EEG as they are rhythmic activities of the brain that can be generated by interactions across neurons. Large-scale oscillations can be measured by EEG as the different oscillation patterns reflected within the different frequency bands, and can provide us with new insights into brain functions. In order to understand how information about the rhythmic activity of the brain during visuomotor/imagined cognitive tasks is encoded in the brain we precisely quantify the different features of the oscillatory patterns considering the Shannon–Fisher plane H × F . This allows us to distinguish the dynamics of rhythmic activities of the brain showing that the Beta band facilitate information transmission during visuomotor/imagined tasks.

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Do Brain Oscillations Orchestrate Memory?

Brain Science Advances ◽

10.26599/bsa.2018.9050008 ◽

2018 ◽

Vol 4 (1) ◽

pp. 16-33 ◽

Cited By ~ 1

Author(s):

Wenhan Luo ◽

Ji-Song Guan

Keyword(s):

Brain Activity ◽

Large Population ◽

Rhythmic Activity ◽

Brain Oscillations ◽

Strongly Coupled ◽

Specific Memory ◽

State Dependent ◽

Neural Communication ◽

The Brain ◽

Oscillatory Waves

Rhythmicity and oscillations are common features in nature, and can be seen in phenomena such as seasons, breathing, and brain activity. Despite the fact that a single neuron transmits its activity to its neighbor through a transient pulse, rhythmic activity emerges from large population-wide activity in the brain, and such rhythms are strongly coupled with the state and cognitive functions of the brain. However, it is still debated whether the oscillations of brain activity actually carry information. Here, we briefly introduce the biological findings of brain oscillations, and summarize the recent progress in understanding how oscillations mediate brain function. Finally, we examine the possible relationship between brain cognitive function and oscillation, focusing on how oscillation is related to memory, particularly with respect to state-dependent memory formation and memory retrieval under specific brain waves. We propose that oscillatory waves in the neocortex contribute to the synchronization and activation of specific memory trace ensembles in the neocortex by promoting long-range neural communication.

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Hippocampal Stimulation of Fornical-lesioned Rats Improves Working Memory

Canadian Journal of Neurological Sciences / Journal Canadien des Sciences Neurologiques ◽

10.1017/s0317167100049003 ◽

1994 ◽

Vol 21 (2) ◽

pp. 100-103 ◽

Cited By ~ 15

Author(s):

J. Turnbull ◽

F. Jiang ◽

R. Racine

Keyword(s):

Working Memory ◽

Memory Impairment ◽

Theta Rhythm ◽

Rhythmic Activity ◽

Hippocampal Theta Rhythm ◽

Disease States ◽

Hippocampal Stimulation ◽

Hippocampal Theta ◽

The Brain ◽

Normal Cognition

Abstract:Intrinsic rhythmic electrical activity in the brain, such as the hippocampal theta rhythm, might serve important roles in normal cognition. Lesions to the medial septal nuclei, or to the fimbria/fornix, disrupt the hippocampal theta rhythm and lead to memory impairment. We have superimposed an artifical stimulating rhythm to the hippocampus of rats with prior lesion of the fornix, during testing in the Morris water maze. This intervention improves performance in a test of working memory, and lends support to the view that intrinsic rhythmic activity may play an important role in normal physiology, and in certain disease states.

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Membrane Potential Oscillations in Reticulospinal and Spinobulbar Neurons During Locomotor Activity

Journal of Neurophysiology ◽

10.1152/jn.00695.2004 ◽

2005 ◽

Vol 94 (1) ◽

pp. 273-281 ◽

Cited By ~ 9

Author(s):

James F. Einum ◽

James T. Buchanan

Keyword(s):

Spinal Cord ◽

Membrane Potential ◽

Locomotor Activity ◽

Brain Stem ◽

Excitatory Amino Acid ◽

Rhythmic Activity ◽

Ventral Root ◽

Potential Oscillations ◽

Bath Application ◽

The Brain

Feedback from the spinal locomotor networks provides rhythmic modulation of the membrane potential of reticulospinal (RS) neurons during locomotor activity. To further understand the origins of this rhythmic activity, the timings of the oscillations in spinobulbar (SB) neurons of the spinal cord and in RS neurons of the posterior and middle rhombencephalic reticular nuclei were measured using intracellular microelectrode recordings in the isolated brain stem-spinal cord preparation of the lamprey. A diffusion barrier constructed just caudal to the obex allowed induction of locomotor activity in the spinal cord by bath application of an excitatory amino acid to the spinal bath. All of the ipsilaterally projecting SB neurons recorded had oscillatory membrane potentials with peak depolarizations in phase with the ipsilateral ventral root bursts, whereas the contralaterally projecting SB neurons were about evenly divided between those in phase with the ipsilateral ventral root bursts and those in phase with the contralateral bursts. In the brain stem under these conditions, 75% of RS neurons had peak depolarizations in phase with the ipsilateral ventral root bursts while the remainder had peak depolarizations during the contralateral bursts. Addition of a high-Ca2+, Mg2+ solution to the brain stem bath to reduce polysynaptic activity had little or no effect on oscillation timing in RS neurons, suggesting that direct inputs from SB neurons make a major contribution to RS neuron oscillations under these conditions. Under normal conditions when the brain is participating in the generation of locomotor activity, these spinal inputs will be integrated with other inputs to RS neurons.

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Evidence for the rhythmic perceptual sampling of auditory scenes

10.1101/618652 ◽

2019 ◽

Cited By ~ 2

Author(s):

Christoph Kayser

Keyword(s):

Time Scale ◽

Temporal Structure ◽

Rhythmic Activity ◽

Acoustic Information ◽

Electrophysiological Recordings ◽

Delta Band ◽

Human Participants ◽

Auditory Scenes ◽

The Brain ◽

Perceptual Weights

AbstractConverging results suggest that perception is controlled by rhythmic processes in the brain. In the auditory domain, neuroimaging studies show that the perception of brief sounds is shaped by rhythmic activity prior to the stimulus and electrophysiological recordings have linked delta band (1-2 Hz) activity to the functioning of individual neurons. These results have promoted theories of rhythmic modes of listening and generally suggest that the perceptually relevant encoding of acoustic information is structured by rhythmic processes along auditory pathways. A prediction from this perspective – which so far has not been tested – is that such rhythmic processes also shape how acoustic information is combined over time to judge extended soundscapes. The present study was designed to directly test this prediction. Human participants judged the overall change in perceived frequency content in temporally extended (1.2 to 1.8 s) soundscapes, while the perceptual use of the available sensory evidence was quantified using psychophysical reverse correlation. Model-based analysis of individual participant’s perceptual weights revealed a rich temporal structure, including linear trends, a U-shaped profile tied to the overall stimulus duration, and importantly, rhythmic components at the time scale of 1 to 2Hz. The collective evidence found here across four versions of the experiment supports the notion that rhythmic processes operating on the delta band time scale structure how perception samples temporally extended acoustic scenes.

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A Computational Study of a Spatiotemporal Mean Field Model Capturing the Emergence of Alpha and Gamma Rhythmic Activity in the Neocortex

Symmetry ◽

10.3390/sym10110568 ◽

2018 ◽

Vol 10 (11) ◽

pp. 568

Author(s):

Wassim Haddad

Keyword(s):

Finite Element ◽

Bifurcation Analysis ◽

Field Model ◽

Computational Study ◽

Mean Field ◽

Rhythmic Activity ◽

Dynamic Equations ◽

Mean Field Model ◽

Pharmacological Agents ◽

The Brain

In this paper, we analyze the spatiotemporal mean field model developed by Liley et al. in order to advance our understanding of the wide effects of pharmacological agents and anesthetics. Specifically, we use the spatiotemporal mean field model for capturing the electrical activity in the neocortex to computationally study the emergence of α - and γ -band rhythmic activity in the brain. We show that α oscillations in the solutions of the model appear globally across the neocortex, whereas γ oscillations can emerge locally as a result of a bifurcation in the dynamics of the model. We solve the dynamic equations of the model using a finite element solver package and show that our results verify the predictions made by bifurcation analysis.

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