The electrical activity of the brain does not only reflect the current level of arousal, ongoing behavior, or involvement in a specific task but is also influenced by what kind of activity, and how much sleep and waking occurred before. The best marker of sleep-wake history is the electroencephalogram (EEG) spectral power in slow frequencies (slow-wave activity, 0.5-4 Hz, SWA) during sleep, whi...

PURPOSE The ILAE recommends baseline recordings of 30 min to detect abnormalities supporting a clinical diagnosis of epilepsy in children. A shorter recording time may be better tolerated by children and be more resource-efficient. Our aim was to determine how many abnormalities supporting a diagnosis of epilepsy would be missed by reducing the recording time of paediatric standard electroencep...

Electroencephalogram (EEG) is the recording of electrical activity through various electrode sensors placed on the scalp. The electrical signal is recorded as waves that can be classified as normal or abnormal. Different types of normal waves can indicate various states or activity levels of the functioning of the brain. Abnormal electricity of the brain may represent many brain disorders, whic...

Spindles appear in the EEG as sinusoidal waves with frequency in the range 11 to 16 Hz. Together with K-complexes they are the hallmarks of NREM sleep and their appearance is taken as evidence of the onset of light sleep. Their specific distribution and exact frequency, changes in early and late sleep during the night. Sleep spindles are also known as “sigma waves” a term initially recommended ...

Electroencephalography (EEG) is a valuable diagnostic test to identify functional disturbances in brain activity. The purpose of this study was to assess the validity of EEG as a diagnostic indicator of intracranial diseases in horses. The validity of EEG was estimated by comparing clinical, clinicopathologic, and histopathologic findings to EEG findings in 20 horses examined for seizures. coll...

The log of the amplitude of EEG waves during NREM sleep is a linear function of the log of their frequency. The slope of this function is reliable within individuals, is significantly less steep in elderly than in young subjects and, in both groups, becomes flatter across successive NREM periods. We interpret these results as consistent with the hypothesis that the function of NREM sleep is to ...

Of ten patients with Reye's syndrome, there were five with stage II or III coma where EEGs revealed 14 c/sec positive bursts in a background of diffuse delta waves. Positive bursts disappeared upon EEG improvement in two survivors and when the EEG became nearly isoelectric in two other patients. Although 14 and 6 c/sec positive bursts are seen commonly during sleep in normal young persons, thei...

EEG and single-unit techniques have been used to study the EEG correlates of cellular firing in the neocortex, n. reticularis (RT) and "specific" thalamic nuclei, and the cholinergic forebrain area (nucleus basalis, NB). Neuronal firing was related to the ongoing behavior of the rat. In addition, using a 16-channel neocortical recording/mapping system, we studied the effects of ibotenic acid le...

The EEG is a valuable tool because it reflects cerebral physiology, it is a continuous and non-invasive measure, and it changes markedly on the administration of anesthetic drugs. The objective of this project is to find the excellent features to discriminate between different anesthesia states. Spectral Edge Frequency (SEF), spectral entropy and bicoherence can be used to differentiate differe...

The effects of long term mental arithmetic task on psychology are investigated by subjective self-reporting measures and action performance test. Based on electroencephalogram (EEG) and heart rate variability (HRV), the impacts of prolonged cognitive activity on central nervous system and autonomic nervous system are observed and analyzed. Wavelet packet parameters of EEG and power spectral ind...