An Adaptive and Learning System for Feedback-Controlled Evoked Response Studies

1981 ◽  
Vol 20 (03) ◽  
pp. 169-173
Author(s):  
J. Wagner ◽  
G. Pfurtscheixer
Keyword(s):  
Brain Activity ◽  
Evoked Response ◽  
Learning System ◽  
Time Interval ◽  
Electrical Brain Activity ◽  
Long Time ◽  
The Subject ◽  
Eeg Power ◽  
Stimulation System ◽  
Background Eeg

The shape, latency and amplitude of changes in electrical brain activity related to a stimulus (Evoked Potential) depend both on the stimulus parameters and on the background EEG at the time of stimulation. An adaptive, learnable stimulation system is introduced, whereby the subject is stimulated (e.g. with light), whenever the EEG power is subthreshold and minimal. Additionally, the system is conceived in such a way that a certain number of stimuli could be given within a particular time interval. Related to this time criterion, the threshold specific for each subject is calculated at the beginning of the experiment (preprocessing) and adapted to the EEG power during the processing mode because of long-time fluctuations and trends in the EEG. The process of adaptation is directed by a table which contains the necessary correction numbers for the threshold. Experiences of the stimulation system are reflected in an automatic correction of this table. Because the corrected and improved table is stored after each experiment and is used as the starting table for the next experiment, the system >learns<. The system introduced here can be used both for evoked response studies and for alpha-feedback experiments.

scholarly journals Use of Multimedia in Punjabi Learning System Design

2018 ◽  
Vol 6 (2) ◽  
pp. 183-189
Author(s):  
Neelam
Keyword(s):  
Instructional Material ◽  
Mother Tongue ◽  
Learning System ◽  
Classroom Teaching ◽  
Great Contribution ◽  
Long Time ◽  
The Subject ◽  
Teaching Learning ◽  
Regional Languages ◽  
Technical Teaching

In this technology era, students are becoming more efficient in coursework because of a better understanding of the subject materials due to the availability of multimedia packages that make teaching-learning an interesting process. In India, the scope of regional languages is limited only to their regions. Hence, more emphasis has been put on the use of Multimedia to develop the mother tongue. The development of instructional material using Multimedia in the Punjabi Language will help the teachers to procure and use these packages in classroom teaching, to make teaching interesting. Also, this will help the teachers to make a shift from traditional methods of teaching to new computerized methods. Due to this, students will able to retain the concepts for a long time as these methods have proved very effective in other courses too. Furthermore, films and print media also have a great contribution towards the technical teaching of these languages to promote the usage of regional languages at the National and International Level.

Skipping Breakfast Affects the Early Steps of Cognitive Processing

2019 ◽  
Vol 33 (2) ◽  
pp. 109-118
Author(s):  
Andrés Antonio González-Garrido ◽  
Jacobo José Brofman-Epelbaum ◽  
Fabiola Reveca Gómez-Velázquez ◽  
Sebastián Agustín Balart-Sánchez ◽  
Julieta Ramos-Loyo
Keyword(s):  
Working Memory ◽  
Cognitive Processing ◽  
Task Difficulty ◽  
Brain Activity ◽  
Reaction Times ◽  
Brain Potentials ◽  
Brain Functioning ◽  
Attentional Processes ◽  
Electrical Brain Activity ◽  
Skipping Breakfast

Abstract. It has been generally accepted that skipping breakfast adversely affects cognition, mainly disturbing the attentional processes. However, the effects of short-term fasting upon brain functioning are still unclear. We aimed to evaluate the effect of skipping breakfast on cognitive processing by studying the electrical brain activity of young healthy individuals while performing several working memory tasks. Accordingly, the behavioral results and event-related brain potentials (ERPs) of 20 healthy university students (10 males) were obtained and compared through analysis of variances (ANOVAs), during the performance of three n-back working memory (WM) tasks in two morning sessions on both normal (after breakfast) and 12-hour fasting conditions. Significantly fewer correct responses were achieved during fasting, mainly affecting the higher WM load task. In addition, there were prolonged reaction times with increased task difficulty, regardless of breakfast intake. ERP showed a significant voltage decrement for N200 and P300 during fasting, while the amplitude of P200 notably increased. The results suggest skipping breakfast disturbs earlier cognitive processing steps, particularly attention allocation, early decoding in working memory, and stimulus evaluation, and this effect increases with task difficulty.

Quantitative evaluation of slow fluctuations of the volume of liquids inside cranial cavity

2019 ◽  
pp. 51-63 ◽  
Author(s):  
Yu. E. Moskalenko ◽  
T. I. Kravchenko ◽  
Yu. V. Novozhilova
Keyword(s):  
Brain Activity ◽  
Sampling Rate ◽  
Age Groups ◽  
Pulse Amplitude ◽  
Cranial Cavity ◽  
Current Frequency ◽  
Physiological Indicators ◽  
Physiological Phenomenon ◽  
Long Time ◽  
Manned Space

Introduction. Slow fl uctuations in the volume and pressure of liquids in the cranial cavity have been known for a long time and have been studied for more than 100 years. However, their quantitative indicators and their practical signifi cance remain unclear until now due to the diffi culties of research. Nevertheless, it was found that they were connected with the brain activity, which made it possible to use them as one of the physiological indicators in studying the problems of manned space fl ights. Goal of research — to study the possibility of using spectral analysis of slow fl uctuations of the volume of liquids inside the cranium in order to realize the quantitative assessment of their indicators with the use of modern microelectronics and computer technology.Materials and methods. In order to solve this problem we created a complex, in which rheoencephalograph-RG-01 («Mizar») was used as a converter-modulator of physiological signals into electrical oscillations. The device was connected with the ADC (Firm «ADIstrument»), Its software allows to calculate the spectrogram with a sampling rate of 128 kHz. Studies were conducted on volunteers of younger, middle and older age groups. The respiratory rate and the electrocardiography were registered together with the rheoencephalography. Electrodes were fi xed on the volonteers′ fronto-mastoid area.Results. Slow fl uctuations the cranium representan independent physiological phenomenon. The most considerable and valuable were fl uctuations in 0,1–0,3 Hz. It was found that current frequency of 100 or 200 kHz and frequency for quantization of 80–100 kHz was optimal for performing their spectrograms. The structure of such diagram consists of 4–7 peaks with amplitude of 0,4–0,7 units compared with REG pulse amplitude. They depend on age and are characterized by hemispheric asymmetry. Spectral diagrams of slow fl ucation inside cranium are representing inpendent physiological phenomenon. These fl uctuations are not connected by common origin, with heart activity and respiration. They are connected by nature with brain activity and PRM.Conclusion. Can be an informative method for diagnostic and assessment of general status of osteopathic patients well as for the assessment of mechanisms of action of some osteopathic techniques.

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. 

The Phantom Defense: America's Pursuit of the Star Wars Illusion. By Craig Eisendrath, Melvin A. Goodman, and Gerald E. Marsh. Westport, CT: Praeger, 2001. 216p. $24.95. Ballistic Missile Defense and the Future of American Security: Agendas, Perceptions, Technology, and Policy. By Roger Handberg. Praeger, 2001. 264p. $62.00. Rockets' Red Glare: Missile Defenses and the Future of World Politics. Edited by James J. Wirtz and Jeffrey A. Larsen. Boulder, CO: Westview, 2001. 368p. $28.50.

2002 ◽  
Vol 96 (4) ◽  
pp. 879-880
Author(s):  
David Goldfischer
Keyword(s):  
World Politics ◽  
Ballistic Missile ◽  
Missile Defense ◽  
Star Wars ◽  
Technological Context ◽  
The Future ◽  
Ballistic Missile Defense ◽  
Long Time ◽  
Strategic Defense ◽  
The Subject

As Michael O'Hanlon concludes in his excellent contribution to Rockets' Red Glare: “We should…get used to the debate over ballistic missile defenses. It has been around a long time, and no final resolution is imminent” (p. 132). In one sense, a review of these three recent books makes clear that many analysts had grown a bit too used to positioning themselves in terms of the 1972 ABM Treaty. Preoccupied with arguments over whether the treaty should be preserved, modified, or rewritten in light of a changing strategic and technological context, no one seemed to have anticipated that President George W. Bush would simply withdraw from it, invoking Article XV's provision that either party could withdraw if “extraordinary events related to the subject matter of this Treaty have jeopardized its supreme interests.” Even many strategic defense supporters who deemed the treaty obsolete (as Robert Joseph persuasively maintains in his contribution to Rockets' Red Glare) generally believed that it should only—and would only—be scrapped if negotiations over U.S.-proposed changes broke down. (“The Bush Administration,” surmises O'Hanlon, “will surely try very hard to amend it before going to such an extreme”) (p. 112). In the event, the president's team disavowed even the word “negotiation,” saying they were willing only to “consult” the Russians regarding the treaty's impending demise.

scholarly journals Delta band activity contributes to the identification of command following in disorder of consciousness

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Gonzalo Rivera-Lillo ◽  
Emmanuel A. Stamatakis ◽  
Tristan A. Bekinschtein ◽  
David K. Menon ◽  
Srivas Chennu
Keyword(s):  
Functional Neuroimaging ◽  
Brain Activity ◽  
Disorder Of Consciousness ◽  
Fine Grained ◽  
Electrical Brain Activity ◽  
Delta Band ◽  
Delta Modulation ◽  
Command Following ◽  
Band Activity

AbstractThe overt or covert ability to follow commands in patients with disorders of consciousness is considered a sign of awareness and has recently been defined as cortically mediated behaviour. Despite its clinical relevance, the brain signatures of the perceptual processing supporting command following have been elusive. This multimodal study investigates the temporal spectral pattern of electrical brain activity to identify features that differentiated healthy controls from patients both able and unable to follow commands. We combined evidence from behavioural assessment, functional neuroimaging during mental imagery and high-density electroencephalography collected during auditory prediction, from 21 patients and 10 controls. We used a penalised regression model to identify command following using features from electroencephalography. We identified seven well-defined spatiotemporal signatures in the delta, theta and alpha bands that together contribute to identify DoC subjects with and without the ability to follow command, and further distinguished these groups of patients from controls. A fine-grained analysis of these seven signatures enabled us to determine that increased delta modulation at the frontal sensors was the main feature in command following patients. In contrast, higher frequency theta and alpha modulations differentiated controls from both groups of patients. Our findings highlight a key role of spatiotemporally specific delta modulation in supporting cortically mediated behaviour including the ability to follow command. However, patients able to follow commands nevertheless have marked differences in brain activity in comparison with healthy volunteers.

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 Amount and location of tectonic uplift in the Urmia region of northwest Iran from the Permian to the Neogene

2021 ◽  
Vol 3 (3) ◽  
Author(s):  
Akram Alizadeh
Keyword(s):  
Hypersaline Lake ◽  
Time Interval ◽  
Lake Basin ◽  
Lake Urmia ◽  
Qom Formation ◽  
Northwest Of Iran ◽  
The Subject ◽  
Orogenic Uplift ◽  
East Azerbaijan ◽  
Urmia Lake Basin

AbstractThe Urmia Lake Basin is located between the West and East Azerbaijan provinces in the northwest of Iran. Lake Urmia is the twentieth largest lake and second largest hypersaline lake in the world. Stratigraphic columns have been constructed, using published information, to compare the sedimentary units deposited from the Permian to the Neogene on the east and west sides of the lake, and to use these to quantity subsidence and uplift. East of the lake, the sedimentary section is more complete and has been the subject of detailed stratigraphic studies, including the compilation of measured sections for some units. West of the lake, the section is incomplete and less work has been done; three columns illustrate variations in the preserved stratigraphy for the time interval. In all cases, the columns are capped by the Oligocene–Miocene Qom Formation, which was deposited during a post-orogenic marine transgression and unconformably overlies units ranging from Precambrian to Cretaceous. Permian to Cretaceous stratigraphy is used to measure subsidence in the Lake Urmia basin up to the end of the Cretaceous, and then, the subsequent orogenic uplift, which was followed by further subsidence recorded by the deposition of the Qom Formation in the Oligocene–Miocene.

scholarly journals Optimal Perturbations of an Oceanic Vortex Lens

Fluids ◽  
2018 ◽  
Vol 3 (3) ◽  
pp. 63 ◽  
Author(s):  
Thomas Meunier ◽  
Claire Ménesguen ◽  
Xavier Carton ◽  
Sylvie Le Gentil ◽  
Richard Schopp
Keyword(s):  
Normal Mode ◽  
Growth Rates ◽  
Time Interval ◽  
Time Intervals ◽  
Horizontal Structure ◽  
Azimuthal Wave ◽  
Wave Numbers ◽  
Non Linear ◽  
Long Time ◽  
Short Time

The stability properties of a vortex lens are studied in the quasi geostrophic (QG) framework using the generalized stability theory. Optimal perturbations are obtained using a tangent linear QG model and its adjoint. Their fine-scale spatial structures are studied in details. Growth rates of optimal perturbations are shown to be extremely sensitive to the time interval of optimization: The most unstable perturbations are found for time intervals of about 3 days, while the growth rates continuously decrease towards the most unstable normal mode, which is reached after about 170 days. The horizontal structure of the optimal perturbations consists of an intense counter-shear spiralling. It is also extremely sensitive to time interval: for short time intervals, the optimal perturbations are made of a broad spectrum of high azimuthal wave numbers. As the time interval increases, only low azimuthal wave numbers are found. The vertical structures of optimal perturbations exhibit strong layering associated with high vertical wave numbers whatever the time interval. However, the latter parameter plays an important role in the width of the vertical spectrum of the perturbation: short time interval perturbations have a narrow vertical spectrum while long time interval perturbations show a broad range of vertical scales. Optimal perturbations were set as initial perturbations of the vortex lens in a fully non linear QG model. It appears that for short time intervals, the perturbations decay after an initial transient growth, while for longer time intervals, the optimal perturbation keeps on growing, quickly leading to a non-linear regime or exciting lower azimuthal modes, consistent with normal mode instability. Very long time intervals simply behave like the most unstable normal mode. The possible impact of optimal perturbations on layering is also discussed.

How Far Scientific is Snakebite Prevention and First Aid Treatment in School Textbook?

2019 ◽  
Vol 31 (1) ◽  
pp. 39-40
Author(s):  
Faiha Fairouz ◽  
Rumana Rashid ◽  
Abdullah Abu Sayeed
Keyword(s):  
Health Problem ◽  
Rural Areas ◽  
Elementary Science ◽  
First Aid ◽  
Primary Treatment ◽  
National Guidelines ◽  
Long Time ◽  
Class Viii ◽  
The Subject ◽  
School Books

Background: Snakebite is an old health problem in rural areas. In Bangladesh, the snakebite issue is included in school syllabus, in curriculum since long time, so that people can take/get immediate first aid treatment and can prevent snakebite. The success of snakebite treatment depends more on providing first aid treatment immediately after snakebite by learning and by sending the patients quickly to hospital. Snakebite is a preventable health problem indeed. If it can be prevented the rate of snakebite will also decrease. In the recently published snake bite management Guideline by WHO it has been targeted to reduce 50% of mortality & disability due to snakebite by 2030.1 Methods: a. The snakebite topic or issue has been thoroughly reviewed in the secondary and higher secondary school books. b. National Guidelines on snakebite in providing/ giving first aid treatment has been reviewed.2 c. The correlation between the topic to learn the subject and the national guidelines have been reviewed and given taken into account. d. The similarity or correlation between the national guidelines and the topic in the prevention of snakebite in the book have been observed & reviewed. It was a descriptive/narrative research study. Results: In the book of class IV in Primary and Secondary level students, ‘Elementary Science, (‘Prathomiik Bigghan’) page no. 86 and in book of class VIII Home Science (‘Gharjhastha Biggan’) page no. 16 the Snakebite issue/topic is mentioned.2,3 There are 22 information on the first aid/primary treatment of Snakebite among which 5 (five) are nonscientific rather harmful. (Table & Picture) Bangladesh J Medicine Jan 2020; 31(1) : 39-40

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