scholarly journals Electroencephalogram patterns with the presence of an unknown musical stimulus

2021 ◽  
Vol 37 ◽  
pp. e37066
Author(s):  
Ana Clara Pereira Resende da Costa ◽  
Camila Davi Ramos ◽  
Amanda Rosa Ferreira-Jorge ◽  
Marcos Campos ◽  
João-Batista Destro-Filho ◽  
...  
Keyword(s):  
Signal Analysis ◽  
Silent Period ◽  
Second Step ◽  
Musical Perception ◽  
Musical Stimulus ◽  
High Gamma ◽  
The Central Nervous System ◽  
Time Variations ◽  
Gamma Rhythms ◽  
Neurologically Normal

The cerebral activity presents different behaviors in different situations and levels of consciousness, especially under musical stimulation. Signals of the central nervous system may disclose bioelectrical patterns, since listening to rhythmic sequences activates specific brain areas. In this paper, we analyze 42 neurologically normal Brazilian individuals, submitted to musical stimulation based on a procedure consisting of three different steps, during which the volunteer is kept with closed eyes. The first step is associated with the preliminary control silence period, without any stimulus, as the volunteer remains at rest. The second step consisted of unknown music stimulation. Finally, the third step involves post-music rest. Quantitative signal analysis computes the power spectrum time variations. Results point out stronger changes in gamma and high gamma waves (30 – 100 Hz). Even though the clinical rhythms (0 – 30 Hz) change throughout the whole period of the experiment, quantitative differences at gamma and high gamma bands are remarkably greater.  Particularly, when comparing the initial silent period and the final post-stimulation silent one, bioelectrical differences are only highlighted by gamma and high gamma rhythms. In consequence, this paper points out that the EEG analysis of cognitive issues related to musical perception cannot disregard gamma and high gamma waves.

Long Latency Reflexes and the Silent Period

2009 ◽  
pp. 543-550
Author(s):  
John N. Caviness
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Motor Control ◽  
Brain Stem ◽  
Silent Period ◽  
Complex Interplay ◽  
Long Latency ◽  
System P ◽  
The Central Nervous System ◽  
Long Latency Reflexes

LLRs and the silent period are EMG phenomena that reflect the complex interplay of spinal, brain stem, and cortical influences in motor control. These techniques have been applied to the study of disorders of motor control such as Parkinson’s disease, Huntington’s disease, and dystonia. Abnormalities of these reflexes may help to detect lesions of the central nervous system.

Salat And Brainwave Signal Analysis

2012 ◽  
Author(s):  
W.Mohd Fatihilkamal W.Mohd Ridzwan ◽  
Nasrul Humaimi Mahmood ◽  
Nor Aini Zakaria ◽  
Elia Ameera Ali
Keyword(s):  
Signal Analysis ◽  
Nervous Activity ◽  
Principal Component ◽  
Gamma Band ◽  
Eeg Signal ◽  
Autonomic Nervous System Dysfunction ◽  
Autonomic Nervous ◽  
High Gamma ◽  
Spectrum Distribution ◽  
Age Range

Solat adalah salah satu cara umat Islam untuk mengabdikan diri kepada Allah. Kajian ini bertujuan untuk mengkaji kesan selepas solat terhadap otak dengan menggunakan Electroencephalograph(EEG) dan kegiatan saraf autonomik. Sebanyak 20 sampel isyarat EEG daripada 5 responden (lelaki berumur di antara 22 hingga 23 tahun) dipilih, dan mereka bebas daripada masalah jantung, paru–paru, metabolik dan penyakit lain yang boleh menggangu kegiatan saraf autonomik. Analisa dilakukan dengan membuat perbandingan di antara sampel EEG bagi dua aktiviti berbeza iaitu aktiviti selepas solat dan aktiviti selepas mendengar muzik menggunakan kaedah analisa prinsip komponen (PCA) dan transformasi fourier (FFT). Hasil analisa ke atas isyarat mendapati amplitud tertinggi pada agihan spektrum kuasa adalah pada jalur gamma bagi EEG berbanding jalur–jalur lain (delta, theta, alpha dan beta) bagi kedua–dua aktiviti. Kajian juga menunjukkan kelima–lima subjek mempunyai jalur gamma yang tinggi selepas solat berbanding selepas mendengar muzik. Keputusan ini mencadangkan, apabila seseorang muslim melakukan solat, mereka akan melupakan seketika masalah mereka dan khusyuk mengadap Allah. Ini dapat membantu memulihkan tekanan yang dialami mereka untuk beberapa ketika, seterusnya lebih bersedia untuk menghadapi segala permasalahan dunia selepas solat. Kata kunci: Solat; electroencephalograph (EEG); isyarat gelombang otak Salat is one of the ways for the Muslims to worship ‘Allah’ (God). This study investigates the brainwave signal after salat using Electroencephalograph (EEG) signal analysis and autonomic nervous activity. Twenty samples of EEG signal from five respondents (males with age range from 22 to 23 years old) were selected, and they were all free from cardiac, pulmonary, metabolic and other disease that would cause autonomic nervous system dysfunction. The analysis of the acquired EEG signal is done by comparing the samples of EEG signal between the activities after salat and after listening to the music using Principal Component Analysis (PCA) and Fast Fourier Transform (FFT) method. The highest amplitude of the power spectrum distribution was observed in the gamma band on EEG compared to other bands (delta, theta, alpha and beta) for both activities. It shows that these five subjects have a high gamma band after salat compared to after listening to music. It is suggested that when Muslim perform salat, they tend to forget all the worldly matters and thinks they are standing in front of the ‘Allah’. This eventually help them to break their stress for a few times, hence reducing its intensity to facing the worlds’ matter after salat. Key words: Solat; electroencephalograph (EEG); brainwave signal

Estimation of the Balance-Keeping Control Law Applied by a Human Being Upon a Sudden Sagittal Tilt Perturbation

2019 ◽  
Vol 141 (4) ◽  
Author(s):  
Nurdan Bilgin ◽  
M. Kemal Özgören
Keyword(s):  
Experimental Data ◽  
Biomechanical Model ◽  
Control Law ◽  
Control Parameters ◽  
Velocity Feedback ◽  
Instantaneous Position ◽  
Sagittal Tilt ◽  
The Central Nervous System ◽  
Time Variations ◽  
Adaptation Scheme

This study aims to estimate the control law employed by the central nervous system (CNS) to keep a person in balance after a sudden disturbance. For this aim, several experiments were carried out, in which the subjects were perturbed sagittally by using a single-axis tilt-platform and their motions were recorded with appropriate sensors. The analysis of the experimental results leads to the contribution of this paper as a conjecture that the CNS commands the muscular actuators of the joints according to an adaptive proportional-derivative (PD) control law such that its gains and set points are updated continuously. This conjecture is accompanied with an assumption that the CNS is able to acquire perfect and almost instantaneous position and velocity feedback by means of a fusion of the signals coming from the proprioceptive, somatosensory, and vestibular systems. In order to verify the conjectured control law, an approximate biomechanical model was developed and several simulations were carried out to imitate the experimentally observed motions. The time variations of the set points and the control gains were estimated out of the experimental data. The simulated motions were observed to be considerably close to the experimental motions. Thus, the conjectured control law is validated. However, the experiments also indicate that the mentioned adaptation scheme is quite variable even for the same subject tested repeatedly with the same perturbation. In other words, this experimental study also leads to the implication that the way the CNS updates the control parameters is not quite predictable.

scholarly journals Multiple gamma rhythms carry distinct spatial frequency information in primary visual cortex

PLoS Biology ◽  
2021 ◽  
Vol 19 (12) ◽  
pp. e3001466
Author(s):  
Chuanliang Han ◽  
Tian Wang ◽  
Yi Yang ◽  
Yujie Wu ◽  
Yang Li ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Spatial Frequency ◽  
Primary Visual Cortex ◽  
Spike Activity ◽  
Brain Regions ◽  
Superficial Layer ◽  
Cortical Level ◽  
High Gamma ◽  
Gamma Rhythms ◽  
Surprising Finding

Gamma rhythms in many brain regions, including the primary visual cortex (V1), are thought to play a role in information processing. Here, we report a surprising finding of 3 narrowband gamma rhythms in V1 that processed distinct spatial frequency (SF) signals and had different neural origins. The low gamma (LG; 25 to 40 Hz) rhythm was generated at the V1 superficial layer and preferred a higher SF compared with spike activity, whereas both the medium gamma (MG; 40 to 65 Hz), generated at the cortical level, and the high gamma HG; (65 to 85 Hz), originated precortically, preferred lower SF information. Furthermore, compared with the rates of spike activity, the powers of the 3 gammas had better performance in discriminating the edge and surface of simple objects. These findings suggest that gamma rhythms reflect the neural dynamics of neural circuitries that process different SF information in the visual system, which may be crucial for multiplexing SF information and synchronizing different features of an object.

scholarly journals Cell type–differential modulation of prefrontal cortical GABAergic interneurons on low gamma rhythm and social interaction

2020 ◽  
Vol 6 (30) ◽  
pp. eaay4073
Author(s):  
Ling Liu ◽  
Haifeng Xu ◽  
Jun Wang ◽  
Jie Li ◽  
Yuanyuan Tian ◽  
...  
Keyword(s):  
Social Interaction ◽  
Functional Differentiation ◽  
Gabaergic Interneurons ◽  
Prefrontal Cortical ◽  
Gamma Frequency ◽  
Gamma Rhythm ◽  
High Gamma ◽  
Gamma Power ◽  
Frequency Stimulation ◽  
Gamma Rhythms

Prefrontal GABAergic interneurons (INs) are crucial for social behavior by maintaining excitation/inhibition balance. However, the underlying neuronal correlates and network computations are poorly understood. We identified distinct firing patterns of prefrontal parvalbumin (PV) INs and somatostatin (SST) INs upon social interaction. Moreover, social interaction closely correlated with elevated gamma rhythms particularly at low gamma band (20 to 50 Hz). Pharmacogenetic inhibition of PV INs, instead of SST INs, reduced low gamma power and impaired sociability. Optogenetic synchronization of either PV INs or SST INs at low gamma frequency improved sociability, whereas high gamma frequency or random frequency stimulation had no effect. These results reveal a functional differentiation among IN subtypes and suggest the importance of low gamma rhythms in social interaction behavior. Furthermore, our findings underscore previously unrecognized potential of SST INs as therapeutic targets for social impairments commonly observed in major neuropsychiatric disorders.

Investigation of Possible Landslide Precursor Activity in a Small-Scale Laboratory Experiment

2018 ◽  
Vol 9 (4) ◽  
pp. 74-86 ◽  
Author(s):  
Spiridon G. Krokidis ◽  
Konstantinos Marmarokopos ◽  
Markos Avlonitis
Keyword(s):  
Signal Analysis ◽  
Energy Content ◽  
Primary Data ◽  
Second Step ◽  
Small Scale ◽  
Frequency Range ◽  
Crack Evolution ◽  
Time Period ◽  
Micro Cracks ◽  
Precursor Activity

The aim of this article is to elucidate the identification and investigation of micro-crack evolution as a landslide precursor activity. For this purpose, the construction of a model test was considered appropriate by simulating a soil landslide in a small scale. There is a direct correlation between slope steepness and the occurrence of landslides. When inclination increases, a few seconds before failure, micro-cracks appear, initiating the slide. The whole procedure was recorded by an accelerometer, intending to record micro cracks imprint. The second step upon primary data acquisition was signal analysis in order to locate and examine micro-crack frequency range either a slide occurred and not. Finally, the signal analysis results indicated that there is a specific time period, a few seconds before failure, which, according to its frequency and energy content, can be defined as a landslide precursor activity. Comparing frequency content between precursor activity time period and no activity one greatly can identify the offset difference.

About the cortical origin of the low-delta and high-gamma rhythms observed in EEG signals during treadmill walking

2014 ◽  
Vol 561 ◽  
pp. 166-170 ◽  
Author(s):  
Thierry Castermans ◽  
Matthieu Duvinage ◽  
Guy Cheron ◽  
Thierry Dutoit
Keyword(s):  
Treadmill Walking ◽  
Eeg Signals ◽  
High Gamma ◽  
Gamma Rhythms

scholarly journals Automatic processing of seismic events recorded on a mini-array Signal analysis combined with neural networks

1994 ◽  
Vol 37 (5) ◽  
Author(s):  
A. Bottero ◽  
Y. Cansi ◽  
B. Massinon
Keyword(s):  
Signal Analysis ◽  
Time Delays ◽  
Cross Correlation ◽  
Automatic Processing ◽  
Travelling Wave ◽  
Comprehensive Analysis ◽  
Second Step ◽  
Seismic Events ◽  
Time Frequency ◽  
Wave Parameters

We present a new method for automatic processing of mini-array records of regional events. It is based on a comprehensive analysis of the cross-correlation functions. This leads to a set of time-delays used to compute the azimuth and velocity of the travelling wave only in case of consisteney of the time-delay set. The second step takes into account the time-frequency representations of these wave parameters to identify each regional wave using a neural network. The resulting standard error on azimuth is 3° and the relative error on distance is less than 20%.

scholarly journals Theta-gamma coupling emerges from spatially heterogeneous cholinergic neuromodulation

2021 ◽  
Vol 17 (7) ◽  
pp. e1009235
Author(s):  
Yihao Yang ◽  
Howard Gritton ◽  
Martin Sarter ◽  
Sara J. Aton ◽  
Victoria Booth ◽  
...  
Keyword(s):  
Sensory Information ◽  
Network Models ◽  
Gamma Activity ◽  
Neural Network Models ◽  
Attentional Processing ◽  
Neural Excitability ◽  
Cholinergic Signaling ◽  
Theta Frequency ◽  
High Gamma ◽  
Gamma Rhythms

Theta and gamma rhythms and their cross-frequency coupling play critical roles in perception, attention, learning, and memory. Available data suggest that forebrain acetylcholine (ACh) signaling promotes theta-gamma coupling, although the mechanism has not been identified. Recent evidence suggests that cholinergic signaling is both temporally and spatially constrained, in contrast to the traditional notion of slow, spatially homogeneous, and diffuse neuromodulation. Here, we find that spatially constrained cholinergic stimulation can generate theta-modulated gamma rhythms. Using biophysically-based excitatory-inhibitory (E-I) neural network models, we simulate the effects of ACh on neural excitability by varying the conductance of a muscarinic receptor-regulated K+ current. In E-I networks with local excitatory connectivity and global inhibitory connectivity, we demonstrate that theta-gamma-coupled firing patterns emerge in ACh modulated network regions. Stable gamma-modulated firing arises within regions with high ACh signaling, while theta or mixed theta-gamma activity occurs at the peripheries of these regions. High gamma activity also alternates between different high-ACh regions, at theta frequency. Our results are the first to indicate a causal role for spatially heterogenous ACh signaling in the emergence of localized theta-gamma rhythmicity. Our findings also provide novel insights into mechanisms by which ACh signaling supports the brain region-specific attentional processing of sensory information.

Saturn's E, G and F rings: modulated by the plasma sheet

1984 ◽  
Vol 75 ◽  
pp. 597
Author(s):  
E. Grün ◽  
G.E. Morfill ◽  
T.V. Johnson ◽  
G.H. Schwehm
Keyword(s):  
Solar Wind ◽  
Direct Contact ◽  
Transport Processes ◽  
Time Variable ◽  
Dust Particles ◽  
Spatial Diffusion ◽  
Drag Forces ◽  
Orbit Perturbation ◽  
Time Variations ◽  
F Ring

ABSTRACTSaturn's broad E ring, the narrow G ring and the structured and apparently time variable F ring(s), contain many micron and sub-micron sized particles, which make up the “visible” component. These rings (or ring systems) are in direct contact with magnetospheric plasma. Fluctuations in the plasma density and/or mean energy, due to magnetospheric and solar wind processes, may induce stochastic charge variations on the dust particles, which in turn lead to an orbit perturbation and spatial diffusion. It is suggested that the extent of the E ring and the braided, kinky structure of certain portions of the F rings as well as possible time variations are a result of plasma induced electromagnetic perturbations and drag forces. The G ring, in this scenario, requires some form of shepherding and should be akin to the F ring in structure. Sputtering of micron-sized dust particles in the E ring by magnetospheric ions yields lifetimes of 102to 104years. This effect as well as the plasma induced transport processes require an active source for the E ring, probably Enceladus.

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