scholarly journals Effect of number and placement of EEG electrodes on measurement of neural tracking of speech

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0246769 ◽  
Author(s):  
Jair Montoya-Martínez ◽  
Jonas Vanthornhout ◽  
Alexander Bertrand ◽  
Tom Francart
Keyword(s):  
Reconstruction Error ◽  
Optimal Number ◽  
Selection Strategy ◽  
Practical Applications ◽  
Auditory Neuroscience ◽  
Eeg Data ◽  
Subject Specific ◽  
Independent Case ◽  
The Subject ◽  
Eeg Recordings

Measurement of neural tracking of natural running speech from the electroencephalogram (EEG) is an increasingly popular method in auditory neuroscience and has applications in audiology. The method involves decoding the envelope of the speech signal from the EEG signal, and calculating the correlation with the envelope of the audio stream that was presented to the subject. Typically EEG systems with 64 or more electrodes are used. However, in practical applications, set-ups with fewer electrodes are required. Here, we determine the optimal number of electrodes, and the best position to place a limited number of electrodes on the scalp. We propose a channel selection strategy based on an utility metric, which allows a quick quantitative assessment of the influence of a channel (or a group of channels) on the reconstruction error. We consider two use cases: a subject-specific case, where the optimal number and position of the electrodes is determined for each subject individually, and a subject-independent case, where the electrodes are placed at the same positions (in the 10-20 system) for all the subjects. We evaluated our approach using 64-channel EEG data from 90 subjects. In the subject-specific case we found that the correlation between actual and reconstructed envelope first increased with decreasing number of electrodes, with an optimum at around 20 electrodes, yielding 29% higher correlations using the optimal number of electrodes compared to all electrodes. This means that our strategy of removing electrodes can be used to improve the correlation metric in high-density EEG recordings. In the subject-independent case, we obtained a stable decoding performance when decreasing from 64 to 22 channels. When the number of channels was further decreased, the correlation decreased. For a maximal decrease in correlation of 10%, 32 well-placed electrodes were sufficient in 91% of the subjects.

scholarly journals Effect of number and placement of EEG electrodes on measurement of neural tracking of speech

2019 ◽  
Author(s):  
Jair Montoya-Martínez ◽  
Alexander Bertrand ◽  
Tom Francart
Keyword(s):  
Reconstruction Error ◽  
Optimal Number ◽  
Selection Strategy ◽  
Practical Applications ◽  
Auditory Neuroscience ◽  
Eeg Data ◽  
Subject Specific ◽  
Independent Case ◽  
The Subject ◽  
Eeg Recordings

AbstractMeasurement of neural tracking of natural running speech from the electroencephalogram (EEG) is an increasingly popular method in auditory neuroscience and has applications in audiology. The method involves decoding the envelope of the speech signal from the EEG signal, and calculating the correlation with the envelope of the audio stream that was presented to the subject. Typically EEG systems with 64 or more electrodes are used. However, in practical applications, set-ups with fewer electrodes are required. Here, we determine the optimal number of electrodes, and the best position to place a limited number of electrodes on the scalp. We propose a channel selection strategy based on an utility metric, which allows a quick quantitative assessment of the influence of a channel (or a group of channels) on the reconstruction error. We consider two use cases: a subject-specific case, where the optimal number and position of the electrodes is determined for each subject individually, and a subject-independent case, where the electrodes are placed at the same positions (in the 10-20 system) for all the subjects. We evaluated our approach using 64-channel EEG data from 90 subjects. In the subject-specific case we found that the correlation between actual and reconstructed envelope first increased with decreasing number of electrodes, with an optimum at around 20 electrodes, yielding 29% higher correlations using the optimal number of electrodes compared to all electrodes. This means that our strategy of removing electrodes can be used to improve the correlation metric in high-density EEG recordings. In the subject-independent case, we obtained a stable decoding performance when decreasing from 64 to 22 channels. When the number of channels was further decreased, the correlation decreased. For a maximal decrease in correlation of 10%, 32 well-placed electrodes were sufficient in 91% of the subjects.

scholarly journals Analysis of miniaturization effects and channel selection strategies for EEG sensor networks with application to auditory attention detection

2019 ◽  
Author(s):  
Abhijith Mundanad Narayanan ◽  
Alexander Bertrand
Keyword(s):  
Sensor Networks ◽  
Channel Selection ◽  
Auditory Attention ◽  
Sensor Nodes ◽  
Selection Strategy ◽  
Long Distance ◽  
Selection Strategies ◽  
Eeg Data ◽  
Eeg Recordings

AbstractObjectiveConcealable, miniaturized electroencephalo-graphy (‘mini-EEG’) recording devices are crucial enablers towards long-term ambulatory EEG monitoring. However, the resulting miniaturization limits the inter-electrode distance and the scalp area that can be covered by a single device. The concept of wireless EEG sensor networks (WESNs) attempts to overcome this limitation by placing a multitude of these mini-EEG devices at various scalp locations. We investigate whether optimizing the WESN topology can compensate for miniaturization effects in an auditory attention detection (AAD) paradigm.MethodsStarting from standard full-cap high-density EEG data, we emulate several candidate mini-EEG sensor nodes which locally collect EEG data with embedded electrodes separated by short distances. We propose a greedy group-utility based channel selection strategy to select a subset of these candidate nodes, to form a WESN. We compare the AAD performance of this WESN with the performance obtained using long-distance EEG recordings.ResultsThe AAD performance using short-distance EEG measurements is comparable to using an equal number of long-distance EEG measurements if in both cases the optimal electrode positions are selected. A significant increase in performance was found when using nodes with three electrodes over nodes with two electrodes.ConclusionWhen the nodes are optimally placed, WESNs do not significantly suffer from EEG miniaturization effects in the case of AAD.SignificanceWESN-like platforms allow to achieve similar AAD performance as with long-distance EEG recordings, while adhering to the stringent miniaturization constraints for ambulatory EEG. Their applicability in an AAD task is important for the design of neuro-steered auditory prostheses.

scholarly journals Energy Distribution Evaluation Using Renyi Entropy Measures With Application in EEG Data Analysis

2021 ◽  
Vol 17 ◽  
pp. 99-107
Author(s):  
Theodor D. Popescu
Keyword(s):  
Energy Distribution ◽  
Medical Diagnosis ◽  
Event Related Potentials ◽  
Eeg Signals ◽  
Time Frequency ◽  
Eeg Data ◽  
Entropy Measures ◽  
Related Potentials ◽  
The Subject ◽  
Eeg Recordings

The ”corrected” EEG recordings, after artifact removing, may be the subject of further investigations, for example segmentation and energy distribution, resulting new informa- tion to be used for feature extraction, of great help for medical diagnosis. The paper presents a generally method for energy distribution evalua- tion using measures of R´enyi entropy. The pre- sented approach ensures the possibility of quan- titative analysis of the information contained in time-frequency distribution of EEG signals. The proposed procedure is applied with good results in the analysis of a sample lowpass event-related potentials (ERP) data, collected from 13 scalp and 1 EOG electrodes.

scholarly journals Disentangling general achievement levels and subject-specific strengths and weaknesses in mathematics, reading, and science

2020 ◽  
Author(s):  
Olesya Gladushyna ◽  
Rolf Strietholt ◽  
Isa Steinmann
Keyword(s):  
Reading Literacy ◽  
Performance Levels ◽  
Fourth Grade Students ◽  
Subject Specific ◽  
The Subject ◽  
Overall Performance ◽  
Cross Country ◽  
And Gender ◽  
Mathematics And Science ◽  
Achievement Levels

AbstractThe paper uses data from the combined TIMSS (Trends in International Mathematics and Science Study) and PIRLS (Progress in International Reading Literacy Study) assessment in 2011 to explore the subject-specific strengths and weaknesses among fourth grade students worldwide. Previous research came to the conclusion that students only differed in overall achievement levels and did not exhibit subject-specific strengths and weaknesses. This research did, however, not control for differences in overall performance levels when searching for profile differences. Therefore, the present study uses factor mixture analysis to study qualitatively different performance profiles in mathematics, reading, and science while controlling for differences in performance levels. Our findings suggest that the majority of students do not show pronounced strengths and weaknesses and differ mainly in performance levels across mathematics, reading, and science. At the same time, a smaller share of students does indeed show pronounced subject-specific strengths and weaknesses. This result does not represent an artefact, but we find clear and theory-conforming associations between the identified profiles and covariates. We find evidence for cross-country differences in the frequency of subject-specific strengths and weaknesses and gender differences, as well as differences between students who do not or only sometimes speak the language of test at home.

Student attitudes towards linear algebra: an attempt to roll back the fog

2020 ◽  
Author(s):  
Barry J Griffiths ◽  
Samantha Shionis
Keyword(s):  
Student Perceptions ◽  
Linear Algebra ◽  
Student Attitudes ◽  
Linear Independence ◽  
Negative Emotions ◽  
Practical Applications ◽  
Key Concepts ◽  
The Subject ◽  
Roll Back

Abstract In this study, we look at student perceptions of a first course in linear algebra, focusing on two specific aspects. The first is the statement by Carlson that a fog rolls in once abstract notions such as subspaces, span and linear independence are introduced, while the second investigates statements made by several authors regarding the negative emotions that students can experience during the course. An attempt is made to mitigate this through mediation to include a significant number of applications, while continually dwelling on the key concepts of the subject throughout the semester. The results show that students agree with Carlson’s statement, with the concept of a subspace causing particular difficulty. However, the research does not reveal the negative emotions alluded to by other researchers. The students note the importance of grasping the key concepts and are strongly in favour of using practical applications to demonstrate the utility of the theory.

Graphed equilibrium parameters of channels formed in sediment

1980 ◽  
Vol 7 (1) ◽  
pp. 93-104 ◽  
Author(s):  
A.W. Peterson ◽  
T. Blench
Keyword(s):  
Subject Matter ◽  
Three Dimensional ◽  
Numerical Data ◽  
Reference List ◽  
Laboratory Measurements ◽  
Practical Applications ◽  
Circular Pipes ◽  
The Subject ◽  
Specialized Mathematics ◽  
Major Reference

This paper, for river engineers and their environmental counterparts, presents and explains the origin and potential of four-dimensional charts that smooth most of the world's numerical data obtained from the equilibrium dimensions of sand rivers, gravel rivers, and laboratory flumes. These charts aim to provide a practical service comparable with that provided by factual plots on the comprehensive classic three-dimensional Stanton friction-factor diagram for circular pipes and clean Newtonian fluid. In the river problems, especially, the existence of different phases (whose transitions are not susceptible to formulation), the inadequacies of textbook theories even for simple phases, and the unavoidable imperfections of both field and laboratory measurements combine to prevent responsible design. The remedy is a graphing of total information backed by references from which its reliability and practicability can be assessed.The references have been chosen to contain principal information in the forms of: (i) usable photos, graphs, and tables; (ii) explanations free from specialized mathematics and speculative arguments; and (iii) papers with discussions, authors' replies, and further useful references (since a major reference list would be too long for this paper). Because condensation has had to be extreme the authors will be glad to attempt answers to discussions and questions on the subject matter, its practical applications, and its implications in teaching and research.

Personalized mathematical model of endotoxin-induced inflammatory responses in young men and associated changes in heart rate variability

2018 ◽  
Vol 13 (5) ◽  
pp. 42 ◽  
Author(s):  
R. Brady ◽  
D.O. Frank-Ito ◽  
H.T. Tran ◽  
S. Janum ◽  
K. Møller ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Inflammatory Responses ◽  
Interleukin 10 ◽  
Tnf Alpha ◽  
Non Invasive ◽  
Estimated Parameters ◽  
Subject Specific ◽  
The Subject ◽  
Necrosis Factor

The objective of this study was to develop a personalized inflammatory model and estimate subject-specific parameters that could be related to changes in heart rate variability (HRV), a measure that can be obtained non-invasively in real time. An inflammatory model was developed and calibrated to measurements of interleukin-6 (IL-6), tumor necrosis factor (TNF-alpha), interleukin-8 (IL-8) and interleukin-10 (IL-10) over 8 hours in 20 subjects administered a low dose of lipopolysaccharide. For this model, we estimated 11 subject-specific parameters for all 20 subjects. Estimated parameters were correlated with changes in HRV, computed from ECG measurements using a built-in HRV module available in Labchart. Results revealed that patients could be separated into two groups expressing normal and abnormal responses to endotoxin. Abnormal responders exhibited increased HRV, most likely as a result of increased vagal firing. The observed correlation between the inflammatory response and HRV brings us a step further towards understanding if HRV predictions can be used as a marker for inflammation. Analyzing HRV parameters provides an easy, non-invasively obtained measure that can be used to assess the state of the subject, potentially translating to identifying a non-invasive marker that can be used to detect the onset of sepsis.

scholarly journals Web Semântica no repositório BRAPCI

2016 ◽  
Vol 9 (2) ◽  
Author(s):  
Nátalia NAKANO ◽  
Talita Cristina da SILVA ◽  
Maria José Vicentini JORENTE ◽  
José Eduardo SANTARÉM SEGUNDO
Keyword(s):  
Semantic Web ◽  
Information Science ◽  
Research Problem ◽  
Human Knowledge ◽  
Practical Applications ◽  
The World ◽  
Working Together ◽  
The Subject ◽  
Web Research ◽  
Productive Authors

In 2001 Tim Berners-Lee revealed to the world what he wanted for the future of Web - man and machine working together to develop complex tasks, and that the Web could leverage the way human knowledge is acquired. Since then researchers from different fields of knowledge have engaged in scientific and empirical research to make this dream come true. In this context, the research problem of this article is established: What is the current situation of Semantic Web research in Brazil in Information Science? Who are the researchers of this theme in our country? What are the institutions that support these studies? The present study aimed at listing the most productive authors, institutions that support their research and the specific issues of their investigations. We conducted a literature review in Base de Dados Referencial de Artigos de Periódicos em Ciência da Informação (BRAPCI). We retrieved 41 articles, excluded five for not belonging to Brazilian authors and Brazilian institutions. From the analysis of this corpus, we realized the need to include additional keywords to better understanding of specific studies encompassed by the theme. Thus, we included the keywords: SPARQL, SKOS, RDF and ontology. It was concluded that the studies on the Semantic Web under the aegis of Information Science mostly perform theoretical and philosophical studies, while the computer science professionals seek practical applications of the topic. It was also concluded that a study including other databases could reveal other authors and institutions relevant to the subject of study.

scholarly journals ‘Learning ENT’ by YouTube videos: perceptions of third professional MBBS students

2020 ◽  
Vol 6 (6) ◽  
pp. 1120
Author(s):  
Ajeet Kumar Khilnani ◽  
Rekha Thaddanee ◽  
Gurudas Khilnani
Keyword(s):  
Teaching And Learning ◽  
Smart Phones ◽  
Online Questionnaire ◽  
Perceptions Of Students ◽  
Subject Specific ◽  
The Subject ◽  
Youtube Videos ◽  
Teaching Learning ◽  
A Prospective Study ◽  
Academic Year

<p class="abstract"><strong>Background:</strong> Advancement in technology has revolutionized the concept of teaching and learning medicine. YouTube is a popular and easily accessible tool to teach medical subjects. This study was done to evaluate the students’ perception of YouTube learning in ENT.</p><p class="abstract"><strong>Methods:</strong> This was a prospective study where a subject specific YouTube channel, ‘Learning ENT’, created by 1st author, was used to upload videos on selected topics in ENT for third professional MBBS part-1 students (n=145). Students were instructed to access the said videos from time to time throughout the year. At the end of the academic year the perceptions of students were taken and analyzed.  </p><p class="abstract"><strong>Results:</strong> 124 students responded to the online questionnaire. 123 (99.2%) watched YouTube videos on their smart phones. 70 students (56.5%) accessed the YouTube videos for ENT topics very often. 122 (98.4%) students felt that these videos made them understand the topics better. Similarly, 115 (92.7%) students felt that these videos enhanced their interest in the subject. 114 (91.9%) students felt that these videos were more beneficial for practical topics in ENT. 61 students (49.2%) perceived that the duration of videos should be 5-10 minutes. Almost equal number (47.6%) students felt that 10-15 minutes duration is appropriate. 79 students (63.7%) perceived that watching videos made the topic easy to understand and also interesting. 71 students (57.2 %) felt that there were no limitations of the said channel.</p><p class="abstract"><strong>Conclusions:</strong> When integrated with other teaching learning methods, YouTube can be an effective tool to facilitate ENT learning.</p>

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