Abstract
The ultradian dynamics of the human waking EEG was studied using a short visual fixation task repeated every 10 min throughout the daytime. The EEG spectra obtained from the tasks were assessed for time effect and ultradian periodicity. Fronto-central EEG high frequency powers (22.5-44.5Hz) decreased at the time of the midafternoon vigilance dip (14.00-17.00h) along with slight concomitant increases in parietal alpha (7.5-13.5 Hz) and delta (1-3 Hz) powers. A slow ultradian rhythm with a 3-4h periodicity strongly modulated EEG power in all frequency bands between 1 and 44.5 Hz. The high frequency waking EEG may well reflect the activity of a brain arousal process underlying maintenance of the waking state probably throughout the 24h cycle. (C) 2000 Lippincott Williams and Wilkins.
Original language | English (US) |
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Pages (from-to) | 2223-2227 |
Number of pages | 5 |
Journal | Neuroreport |
Volume | 11 |
Issue number | 10 |
DOIs | |
State | Published - Jul 14 2000 |
Externally published | Yes |
Keywords
- Alertness
- Arousal
- EEG
- High frequency activity
- Human
- Sleepiness
- Spectral analysis
- Ultradian rhythms
- Vigilance
- Wakefulness
ASJC Scopus subject areas
- General Neuroscience