With extracting separately delta, theta, alpha and beta rhythms of electroencephalogram (EEG), we studied the characters of EEG for fatigued drivers by analyzing relative power spectrum, power spectral entropy and brain electrical activity mapping. The experimental results showed that with the average relative power spectrum in delta and theta rhythms of EEG increasing, the average relative power spectrum in alpha and beta rhythms decreased, while the average relative power spectrum in delta, theta and alpha rhythms increased in deep fatigue. The average power spectral entropy of EEG decreases with the increasing fatigue level. The average relative power spectrum and the average power spectral entropy of EEG could be expected to serve as the index for detecting fatigue level of drivers.
Automobile Driving ; Brain Waves ; physiology ; Electroencephalography ; Fatigue ; physiopathology ; Humans ; Monitoring, Physiologic ; Signal Processing, Computer-Assisted

The two basic scripts of the Korean writing system, Hanja (the logography of the traditional Korean character) and Hangul (the more newer Korean alphabet), have been used together since the 14th century. While Hanja character has its own morphemic base, Hangul being purely phonemic without morphemic base. These two, therefore, have substantially different outcomes as a language as well as different neural responses. Based on these linguistic differences between Hanja and Hangul, we have launched two studies; first was to find differences in cortical activation when it is stimulated by Hanja and Hangul reading to support the much discussed dual-route hypothesis of logographic and phonological routes in the brain by fMRI (Experiment 1). The second objective was to evaluate how Hanja and Hangul affect comprehension, therefore, recognition memory, specifically the effects of semantic transparency and morphemic clarity on memory consolidation and then related cortical activations, using functional magnetic resonance imaging (fMRI) (Experiment 2). The first fMRI experiment indicated relatively large areas of the brain are activated by Hanja reading compared to Hangul reading. The second experiment, the recognition memory study, revealed two findings, that is there is only a small difference in recognition memory for semantic transparency, while for the morphemic clarity was much larger between Hanja and Hangul. That is the morphemic clarity has significantly more effect than semantic transparency on recognition memory when studies by fMRI in correlation with behavioral study.
Adult ; Brain/*physiology ; Brain Mapping/*methods ; Brain Waves/*physiology ; Female ; Humans ; Magnetic Resonance Imaging ; Male ; Neurolinguistic Programming ; Recognition (Psychology)/physiology ; Writing

Transcranial direct current stimulation (tDCS) has become a new method of post-stroke rehabilitation treatment and is gradually accepted by people. However, the neurophysiological mechanism of tDCS in the treatment of stroke still needs further study. In this study, we recruited 30 stroke patients with damage to the left side of the brain and randomly divided them into a real tDCS group (15 cases) and a sham tDCS group (15 cases). The resting EEG signals of the two groups of subjects before and after stimulation were collected, then the difference of power spectral density was analyzed and compared in the band of delta, theta, alpha and beta, and the delta/alpha power ratio (DAR) was calculated. The results showed that after real tDCS, delta band energy decreased significantly in the left temporal lobes, and the difference was statistically significant ( P < 0.05); alpha band energy enhanced significantly in the occipital lobes, and the difference was statistically significant ( P < 0.05); the difference of theta and beta band energy was not statistically significant in the whole brain region ( P > 0.05). Furthermore, the difference of delta, theta, alpha and beta band energy was not statistically significant after sham tDCS ( P > 0.05). On the other hand, the DAR value of stroke patients decreased significantly after real tDCS, and the difference was statistically significant ( P < 0.05), and there was no significant difference in sham tDCS ( P > 0.05). This study reveals to a certain extent the neurophysiological mechanism of tDCS in the treatment of stroke.
Brain/physiopathology* ; Brain Waves/physiology* ; Electroencephalography/methods* ; Humans ; Stroke/therapy* ; Stroke Rehabilitation/methods* ; Transcranial Direct Current Stimulation/methods*

Anticonvulsants ; therapeutic use ; Brain ; pathology ; physiopathology ; Brain Waves ; physiology ; Child ; Electroencephalography ; Humans ; Landau-Kleffner Syndrome ; physiopathology ; Sleep ; physiology ; Sleep Stages ; physiology ; Status Epilepticus ; epidemiology ; etiology ; physiopathology ; therapy

The performance of an electroencephalography (EEG) automatic detection and classification system mainly depends on the feature extraction of EEG signal. This paper analyses the advantages and disadvantages of the current EEG feature extraction methods, and then presents a new EEG feature extraction method based on echo state networks (ESN). The new method is a nonlinear method, and can extract the EEG features reversibly. Therefore, the information lost in the process of feature extraction is much less than that of the traditional EEG. Additionally, the realization of this method just needs to compute the pseudo inverse of a matrix, which keeps it efficient. Experimental results have showed that the new method could well accomplish the task of automatic detection and classification of EEG signals.
Algorithms ; Brain Waves ; physiology ; Electroencephalography ; instrumentation ; methods ; Epilepsy ; physiopathology ; Humans ; Neural Networks (Computer) ; Signal Processing, Computer-Assisted

This paper generalizes the seizures characterized with paroxysmal generalized spike and wave discharges (GSWDs) in the EEG. Recent studies showed that GSWDs disrupt specific neural networks only rather than the entire brain homogenously. Simultaneous EEG and functional MRI (EEG-fMRDI) provides a high spatiotemporal resolution method for uncovering the regions of the brain showing changes in metabolism and blood flow during epileptic activity. Human EEG-fMRI studies to date have revealed the blood oxygenation level dependent (BOLD) signal changes in response to GSWDs in some specific brain regions. Most studies have noted similar BOLD signals decrease in the bilateral cortical regions including frontal, frontal-parietal, posterior cingulated and precuneus cortex, as well as in the basal ganglia, and BOLD signals increase in the bilateral thalamic. Further studies demonstrated that BOLD signals in different regions were dynamic changes in the time course of GSWDs and BOLD changes in the cortical areas occurred before in the thalamus. These cortical-subcortical structures may form the neural networks associated with GSWDs generation and maintenance. More sophisticated analytic techniques will be developed to explore the BOLD time-course of GSWDs and identify the brain structures involved in seizure onset and discharges propagation respectively. The sub-network associated with different behavioral deficits between interical and ictal GSWDs, and the different subtypes of generalized seizures will be further studied. The functional connectivity of the nodes of the neural network of GSWDs can also be further investigated. A better understanding of the neural network responsible for GSWDs generation may help to develop new therapeutic interventions.
Animals ; Brain ; physiopathology ; Brain Mapping ; Brain Waves ; physiology ; Electroencephalography ; Epilepsy, Generalized ; physiopathology ; Humans ; Image Processing, Computer-Assisted ; Magnetic Resonance Imaging ; Neural Networks (Computer)

The thalamostriatal pathway is implicated in Parkinson's disease (PD); however, PD-related changes in the relationship between oscillatory activity in the centromedian-parafascicular complex (CM/Pf, or the Pf in rodents) and the dorsal striatum (DS) remain unclear. Therefore, we simultaneously recorded local field potentials (LFPs) in both the Pf and DS of hemiparkinsonian and control rats during epochs of rest or treadmill walking. The dopamine-lesioned rats showed increased LFP power in the beta band (12 Hz-35 Hz) in the Pf and DS during both epochs, but decreased LFP power in the delta (0.5 Hz-3 Hz) band in the Pf during rest epochs and in the DS during both epochs, compared to control rats. In addition, exaggerated low gamma (35 Hz-70 Hz) oscillations after dopamine loss were restricted to the Pf regardless of the behavioral state. Furthermore, enhanced synchronization of LFP oscillations was found between the Pf and DS after the dopamine lesion. Significant increases occurred in the mean coherence in both theta (3 Hz-7 Hz) and beta bands, and a significant increase was also noted in the phase coherence in the beta band between the Pf and DS during rest epochs. During the treadmill walking epochs, significant increases were found in both the alpha (7 Hz-12 Hz) and beta bands for two coherence measures. Collectively, dramatic changes in the relative LFP power and coherence in the thalamostriatal pathway may underlie the dysfunction of the basal ganglia-thalamocortical network circuits in PD, contributing to some of the motor and non-motor symptoms of the disease.
Animals ; Brain Waves ; physiology ; Corpus Striatum ; physiopathology ; Cortical Synchronization ; physiology ; Dopaminergic Neurons ; physiology ; Electrocorticography ; Male ; Neural Pathways ; physiopathology ; Oxidopamine ; Parkinsonian Disorders ; physiopathology ; Rats, Wistar ; Thalamic Nuclei ; physiopathology ; Walking ; physiology

To optimize the monitoring time of interictal epileptiform discharges (IED) in patients with epilepsy by long-term video electroencephalogram (VEEG).The cumulative percentages of IED detected by VEEG in 346 epilepsy patients (349 times) with different purposes, different waking sleep states and different MRI findings were retrospectively analyzed. According to the purposes, there were 164 patients (165 times) for clarifying diagnosis, 124 patients (124 times) for preoperative evaluation and 58 patients (60 times) for adjustment of medications. According to MRI results, there were responsible lesions in 98 patients (98 times) and no responsible lesions in 173 patients (174 times).Among 346 patients (349 times), IED was detected within 24 h in 231 patients (times). The percentage of detection in patients with purpose of preoperative evaluation was higher than those with purpose of diagnosis and medication adjustment. The detection of LED was gradually increased in first 8 h with 59.0%, then stably in 24 h. 46.8% IED was recorded during sleep time, particularly in the second stage of sleep. The cumulative percentage of IED in patients with abnormal MRI findings was higher in all periods. It reached 83.7% within 8 h, and then tended to be stable.The study shows that LED should be monitored by VEEG at least 8 hours and should include the second stage of sleep in patients with epilepsy. Patients with refractory epilepsy and with abnormal lesions on MRI should record IED more frequently.
Brain ; diagnostic imaging ; pathology ; Brain Waves ; Electroencephalography ; methods ; statistics & numerical data ; Epilepsy ; pathology ; physiopathology ; Female ; Humans ; Magnetic Resonance Imaging ; statistics & numerical data ; Male ; Retrospective Studies ; Sleep ; physiology ; Time Factors

OBJECTIVETo analyze the clinical diagnosis and treatment process of narcolepsy and epilepsy co-existence, and thereby to improve awareness of such cases.

METHODThe clinical manifestations of 2 cases were observed, and video-electroencephalogram (VEEG), multiple sleep latency tests (MSLT) were performed. Hypocretin 1 level in cerebrospinal fluid was examined in one case.

RESULTThe onset of disease of case one was started with epilepsy with myoclonic seizure. After half a year, catalepsy induced by emotion especially laughing and excessive daytime sleepiness appeared. MSLT was positive and hypocretin 1 level decreased. Narcolepsy-cataplexy was definitely diagnosed in this case. Valproate was given and seizure was controlled completely, but the excessive daytime sleepiness was aggravated. Combination of valproate, methylphenidate and clomipramine treatment improved the symptoms of narcolepsy and the patient was still free of epileptic seizures. The onset symptoms of case 2 were catalepsy and excessive daytime sleepiness. MSLT was positive. The treatment was ineffective because of bad compliance. After 2 years, episodes of impairment of consciousness with automatism occurred. VEEG showed slow waves and spikes in right temporal area. Complex partial seizure was determined. Oxcarbazepine was used and then the patients became seizures free, but the symptoms of narcolepsy were still obvious.

CONCLUSIONComorbidity of narcolepsy and epilepsy is a rare phenomenon. Clinical symptoms, predisposing factor, VEEG and MSLT can help diagnosis and differential diagnosis. The antiepileptic drugs might aggravate drowsiness. Based on therapy of epilepsy by using antiepileptic drugs, low dosage of central nervous system stimulants might improve the drowsiness and catalepsy symptoms of narcolepsy.

Adolescent ; Anticonvulsants ; administration & dosage ; therapeutic use ; Brain Waves ; physiology ; Central Nervous System Stimulants ; administration & dosage ; therapeutic use ; Child ; Comorbidity ; Diagnosis, Differential ; Electroencephalography ; Epilepsies, Myoclonic ; diagnosis ; drug therapy ; physiopathology ; Epilepsy ; diagnosis ; drug therapy ; physiopathology ; Humans ; Intracellular Signaling Peptides and Proteins ; cerebrospinal fluid ; Male ; Narcolepsy ; diagnosis ; drug therapy ; physiopathology ; Neuropeptides ; cerebrospinal fluid ; Orexins ; Polysomnography ; Sleep Stages ; physiology ; Treatment Outcome