Energy Distribution and Coherence-Based Changes in Normal and Epileptic Electroencephalogram

Shriram, Revati; Baskar, V. Vijaya; Martin, Betty; Sundhararajan, M.; Daimiwal, Nivedita

doi:10.1007/978-981-13-1921-1_61

Cited by 5 publications

(4 citation statements)

References 12 publications

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“…For visual fatigue, the length of saccades, the fixation durations, and features related to blinking collected from eye tracking devices were often used as indicators [ 42 ]. In the evaluation of cognitive workload/fatigue, Shriram et al [ 43 ] discovered that electroencephalography (EEG) measures were useful in finding and evaluating the relative contributions of workload that were not detected by other indexes.…”

Section: Literature Reviewmentioning

confidence: 99%

Desktop lighting for comfortable use of a computer screen

Han

Zhang

Xiang

et al. 2021

WOR

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BACKGROUND: The contrast between a bright computer screen and a dark ambient environment may influence comfort of the users, especially on their eyes. OBJECTIVE: The objective of this research is to identify the optimal desktop lighting for the comfortable use of the computer screen in a dark environment. METHODS: An experiment was designed where seven illumination setups were introduced for the users to perform their leisure tasks on a computer screen. Fifteen healthy subjects participated in the experiments. During each session, durations of the eye blinks, fixations and saccades of the user were recorded by an eye tracker. His/her neck and trunk movements were recorded by a motion tracking system as well. The comfort/discomfort questionnaire, localized postural discomfort questionnaire, NASA task load index and computer user questionnaire were used to record the overall comfort/discomfort, the local perceived physical discomfort, the cognitive workload, and general/eye health problems, respectively. RESULTS: Subjective and objective measurement results indicated that users felt more comfortable with high intensity warm lights using a computer screen. We also identified that the eye fixation durations, as well as the scores of two questions in the computer user questionnaire, have significant negative correlations with comfort. On the other side, the durations of blinks and the scores of three questions in the computer user questionnaire, were significantly correlated with discomfort. CONCLUSION: The warm (3000K) and high intensity (1500 lux) light reduced the visual and cognitive fatigue of the user and therefore improve the comfort of the user during the use of a computer screen.

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Section: Literature Reviewmentioning

confidence: 99%

Desktop lighting for comfortable use of a computer screen

Han

Zhang

Xiang

et al. 2021

WOR

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“…In summary, the interhemispheric mean spectral coherence values for the full band, alpha band, theta, and delta bands are lower in the ictal period than in the preictal period. A similar result is found in the study by Julkunen et al .,[ 46 ] Narasimhan et al .,[ 47 ] and Shriram et al .,[ 34 ] which found the decrease of coherence in the delta, theta, and alpha bands. Song et al .…”

Section: Discussionmentioning

confidence: 99%

“…[ 33 ] Shriram et al . [ 34 ] observed the mean coherence in five EEG bands. It shows that the mean coherence of delta, theta, and alpha bands is higher than the other sub-bands in the normal condition.…”

Section: Introductionmentioning

confidence: 99%

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Quantitative Analysis of Inter- and Intrahemispheric Coherence on Epileptic Electroencephalography Signal

Wijayanto

Hartanto

Nugroho

2022

Journal of Medical Signals &Amp; Sensors

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When an epileptic seizure occurs, the neuron's activity of the brain is dynamically changed, which affects the connectivity between brain regions. The connectivity of each brain region can be quantified by electroencephalography (EEG) coherence, which measures the statistical correlation between electrodes spatially separated on the scalp. Previous studies conducted a coherence analysis of all EEG electrodes covering all parts of the brain. However, in an epileptic condition, seizures occur in a specific region of the brain then spreading to other areas. Therefore, this study applies an energy-based channel selection process to determine the coherence analysis in the most active brain regions during the seizure. This paper presents a quantitative analysis of inter- and intrahemispheric coherence in epileptic EEG signals and the correlation with the channel activity to glean insights about brain area connectivity changes during epileptic seizures. The EEG signals are obtained from ten patients’ data from the CHB-MIT dataset. Pair-wise electrode spectral coherence is calculated in the full band and five sub-bands of EEG signals. The channel activity level is determined by calculating the energy of each channel in all patients. The EEG coherence observation in the preictal (Cohpre ) and ictal (Cohictal ) conditions showed a significant decrease of Cohictal in the most active channel, especially in the lower EEG sub-bands. This finding indicates that there is a strong correlation between the decrease of mean spectral coherence and channel activity. The decrease of coherence in epileptic conditions (Cohictal <Cohpre ) indicates low neuronal connectivity. There are some exceptions in some channel pairs, but a constant pattern is found in the high activity channel. This shows a strong correlation between the decrease of coherence and the channel activity. The finding in this study demonstrates that the neuronal connectivity of epileptic EEG signals is suitable to be analyzed in the more active brain regions.

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Analysis of Parameters Distribution of EEG Signals for Five Epileptic Seizure Phases Modeled by Duffing Van Der Pol Oscillator

Szuflitowska

Orłowski

2022

Computational Science – ICCS 2022

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Energy Distribution and Coherence-Based Changes in Normal and Epileptic Electroencephalogram

Cited by 5 publications

References 12 publications

Desktop lighting for comfortable use of a computer screen

Desktop lighting for comfortable use of a computer screen

Quantitative Analysis of Inter- and Intrahemispheric Coherence on Epileptic Electroencephalography Signal

Analysis of Parameters Distribution of EEG Signals for Five Epileptic Seizure Phases Modeled by Duffing Van Der Pol Oscillator

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