• Sleep Medicine and Psychophysiology
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• v.15 no.1
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• pp.33-38
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• 2008

Introduction: It has been proposed that narcolepsy and REM sleep behavior disorder (RBD) have overlapped symptom profile and pathophysiology. This study was aimed at measuring and comparing changes in EEG frequency band of REM sleep in narcolepsy and RBD, applying EEG spectral analysis method. Methods: Nine patients diagnosed as narcolepsy and the same number of RBD patients were studied. Spectral analysis of the REM sleep EEG was performed in each patient on 9 epochs selected evenly from the first, second, and third REM periods. Then, we compared frequency band percentages of REM sleep EEG in narcolepsy and RBD. Results: Narcolepsy patients had significantly higher delta frequency ratio than RBD ones (p=0.00). In alpha and beta2 frequency bands, RBD patients showed higher percentage than narcolepsy ones. Slow wave sleep was more prevalent in narcolepsy patients. But, no difference of REM sleep percentage was found between the two groups (p=0.93). Conclusion: Higher delta frequency ratio in REM sleep of narcolepsy patients than RBD ones reflects that sleep-promoting mechanism is more dominant in narcolepsy than in RBD.

• Natural Product Sciences
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• v.15 no.4
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• pp.213-221
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• 2009

Longanae Arillus (the rind of fruits of Dimocarpus longan) has been consumed for the treatment of insomnia and anxiety in Asia. To provide further scientific basis to traditional uses of this fruit on insomnia, we evaluated the effects of methanol extract of Longanae Arillus (MELA) on the alteration of sleep architecture and electroencephalogram (EEG) power spectra in acutely and chronically restraint-stressed rats. Following postsurgical recovery, Polygraphic signs of sleep-wake activities were recorded for 24 h after MELA administration in rats. Rats in the acute stress and chronic stress were administered with MELA for 10 days. On the $8^{th},\;9^{th}\;and\;10^{th}$ day of MELA administration, the rats were stressed for 3 h once per day. On the $10^{th}$ day and 1 h after MELA administration, the rats were stressed once for 22 h in the chronic stress group. Acute and chronic stress induced alternations in cortex EEG recordings during non-rapid eye movement (NREM), rapid eye movement (REM) sleep and wakefulness. MELA shortened the total and REM sleep and increased the wakefulness in night time recording without changing daytime recordings. Chronic stress increased wakefulness and REM sleep, decreased total and NREM sleep in the daytime recording, and increased REM and decreased NREM sleep without changing total sleep and wakefulness in night time recording. These findings suggest that MELA ameliorated the alterations in REM and NREM sleep of acutely and chronically stressed rats via modulation of cortical ${\alpha}-$, ${\theta}-$ and ${\delta}-$ wave activity.

• Journal of Korea Multimedia Society
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• v.17 no.2
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• pp.113-123
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• 2014

Electrophysiological recordings are considered a reliable method of assessing a person's alertness. Sleep medicine is asked to offer objective methods to measure daytime alertness, tiredness and sleepiness. As EEG signals are non-stationary, the conventional method of frequency analysis is not highly successful in recognition of alertness level. In this paper, EEG signals have been analyzed using wavelet transform as well as discrete wavelet transform and classification using statistical classifiers such as euclidean and mahalanobis distance classifiers and a promising method SVM (Support Vector Machine). As a result of simulation, the average values of accuracies for the Linear Discriminant Analysis (LDA)-Quadratic, k-Nearest Neighbors (k-NN)-Euclidean, and Linear SVM were 48%, 34.2%, and 86%, respectively. The experimental results show that SVM classification method offer the better performance for reliable classification of the EEG signal in comparison with the other classification methods.

• Journal of Korea Multimedia Society
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• v.21 no.5
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• pp.609-616
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• 2018

In this paper, we designed a multimodal bio-signal measurement system to observe changes in the brain nervous system and vascular system during sleep. Changes in the nervous system and the cerebral blood flow system in the brain during sleep induce a unique correlation between the changes in the nervous system and the blood flow system. Therefore, it is necessary to simultaneously observe changes in the brain nervous system and changes in the blood flow system to observe the sleep state. To measure the change of the nervous system, EEG, EOG and EMG signal used for the sleep stage analysis were designed. We designed a system for measuring cerebral blood flow changes using functional near-infrared spectroscopy. Among the various imaging methods to measure blood flow and metabolism, it is easy to measure simultaneously with EEG signal and it can be easily designed for miniaturization of equipment. The sleep stage was analyzed by the measured data, and the change of the cerebral blood flow was confirmed by the change of the sleep stage.

• Journal of Life Science
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• v.12 no.4
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• pp.375-382
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• 2002

The purpose of this experiment was to examine influence of acute exercise on nocturnal sleep which had been disrupted by caffeine(400mg$\times$3) thought the daytime. Six healthy young males aged 21.0$\times$0.2 yr with a history of low caffeine use. Subjects completed three conditions in a within-subject. At three conditions Sleep EEG were investigated: (1) nocturnal following quiet rest, (2) nocturnal sleep following the consumption of 1200mg of caffeine (3) nocturnal sleep following cycling at 60 min of 60% V $O_{2peak}$ with 1200mg of caffeine consumption. Sleep data were calculated for REM sleep, REM latency, sleep onset latency, sleep efficiency, sleep stages, SWS. Those data were analyzed using repeated-measures ANOVA of change scores. A main effect to, drug(caffeine) indicated that caffeine elicited sleep disturbance that is, TST and sleep onset latency increase and sleep efficiency and stage 4 decrease. The effects of exercise on sleep following caffeine intake generally improve sleep that is, stage 2, 3 and SWS increase and sleep onset latency decrease. A condition effect for sleep indicated sleep improvement after exercise Therefore The data supported a restorative theory of slow-wave sleep and suggest that acute exercise may be useful in promoting sleep and reducing sleep disturbance elevated by a high dose of caffeine.

• Journal of Life Science
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• v.22 no.5
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• pp.613-620
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• 2012

To evaluate the effects of sleep habits on the powers of beta waves and the sensory motor rhythm of the electroencephalogram (EEG), female college student subjects were divided into four groups, according to their sleep habits, as follows: GSHG (Good Sleep Habit Group), CSHG (Common Sleep Habit Group: late bedtime), CSDG (Cognitive Sleep Disorder-Delayed Sleep Phase Syndrome Group), and NSDG (Non-cognitive Sleep Disorder-Delayed Sleep Phase Syndrome Group). Brain function was stimulated by reading a book for 3 min in the morning (9~12 am) and the EEG was measured. According to the results, the powers of the beta waves and sensory motor rhythm were not different during the resting period among the four groups. However, during the reading stimulation period, the powers of beta waves and the sensory motor rhythm in the GSHG were significantly greater than in the other groups ($p$ <0.05). Beta powers during stimulation also increased in all brain areas in the GSHG ($p$ <0.05). Interestingly, these were decreased in the frontal and temporal lobes in the CSHG by the reading stimulation ($p$ <0.05). On the other hand, sensory motor rhythm, which represents focusing efficacy, only improved in the GSHG. These results indicate that the brain's focusing function during the reading stimulation was not properly operating in the morning in the female college students who had a delayed bedtime and bad sleep habits.

• Journal of Biomedical Engineering Research
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• v.44 no.6
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• pp.392-403
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• 2023

This study presents a new hybrid fNIRS-EEG system to meet the demand for a lightweight and low-cost sleep pattern monitoring device. For multiple-channel configuration, a six-channel electroencephalogram (EEG) and a functional near-infrared spectroscopy (fNIRS) system with eight photodiodes (PD) and four dual-wavelength LEDs are designed. To enhance the convenience of signal measurement, the device is miniaturized into a patch-like form, enabling simultaneous measurement on the forehead. Due to its fully integrated functionality, the developed system is advantageous for performing sleep stage classification with high-temporal and spatial resolution data. This can be realized by utilizing a two-dimensional (2D) brain activation map based on the concentration changes in oxyhemoglobin and deoxyhemoglobin during sleep stage transitions. For the system verification, the phantom model with known optical properties was tested at first, and then the sleep experiment for a human subject was conducted. The experimental results show that the developed system qualifies as a portable hybrid fNIRS-EEG sleep pattern monitoring device.

• Smart Media Journal
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• v.10 no.2
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• pp.55-60
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• 2021

In this research, we design and perform experiment to investigate whether neuronal activity patterns elicited while solving game tasks are spontaneously reactivated in during sleep. In order to recognize human activity EEG-fMRI signals are used at the same time. Experimental results shows that reward for the success of tasks performed before sleeping have an effect on sleep brain activity. The study uncovers a neural mechanism whereby rewarded life experiences are preferentially replayed and consolidated while we sleep.

• Sleep Medicine and Psychophysiology
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• v.2 no.1
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• pp.31-43
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• 1995

Recently, the methods that measure and analyze brain electrical activity quantitatively have been available with the rapid development of computer technology. The quantitative electroencephalography(QEEG) is a method of computer-assisted analyzing brain electrical activity. The QEEG allows for a more sensitive, precise and reproducible examination of EEG data than that can be accomplished by conventional EEG. It is possible to compare various EEG parameters each other by using QEEG. Neurometrics, a kind of the quantitative EEG. is to compare EEG characteristics of the patient with normative data to determine in what way the patient's EEG deviates from normality and to discriminate among psychiatric disorders. Nowadays, QEEG is far superior to conventional EEG in its detection of abnormality and in its usefulness in psychiatric differential diagnosis. The abnormal findings of QEEG in various psychiatric disorders are also discussed.

• Fisheries and Aquatic Sciences
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• v.17 no.1
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• pp.19-25
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• 2014

We investigated the effects of Ecklonia cava ethanol extract (ECE) on sleep architecture and sleep profiles. ECE was orally administered at a dose of 100, 250, or 500 mg/kg to C57BL/6N mice and its effects were measured by recording electroencephalogram (EEG) and electromyogram. Administration of ECE (250 and 500 mg/kg) significantly induced non-rapid eye movement sleep (NREMS) without affecting rapid eye movement sleep. The increase in NREMS by ECE (500 mg/kg) was significant (P < 0.05) during the first 2 h after administration. In addition, ECE had no effect on EEG power density (an indicator of sleep quality) in NREMS. These results suggest that ECE induces NREMS in a manner similar to physiological sleep.