This research was supported by a Natural Sciences and Engineering Research Council (NSERC) grant to R.D.O. Portions of these data were presented to the Association of Professional Sleep Societies (APSS) third annual meeting in Washington, DC, June, 1989.
Behavioral, Event-Related Potential, and EEG/FFT Changes at Sleep Onset
Article first published online: 30 JAN 2007
Volume 28, Issue 1, pages 54–64, January 1991
How to Cite
Ogilvie, R. D., Simons, I. A., Kuderian, R. H., MacDonald, T. and Rustenburg, J. (1991), Behavioral, Event-Related Potential, and EEG/FFT Changes at Sleep Onset. Psychophysiology, 28: 54–64. doi: 10.1111/j.1469-8986.1991.tb03386.x
- Issue published online: 30 JAN 2007
- Article first published online: 30 JAN 2007
- Manuscript received August 2, 1989; accepted for publication March 16, 1990
- Sleep onset;
- Arousal level;
- Sleep onset period;
- Sleep/Wake definition;
- Fourier analysis (FFT);
- Event-related potentials (ERPs)
Behavioral, event-related potential (ERP), and EEG measures were obtained to describe more fully the relationship between brain activity and arousal level during the process of falling asleep. In addition to standard polysomnographic measures, tones were presented at random intervals throughout two nights to each of nine subjects. Subjects were instructed to respond to the tones whenever they heard them. Initial sleep onset was disrupted five times following zero through four successive response failures. Sampling of EEG was initiated 5 s prior to tone onset (EEG analyses) and continued for 5 s following tone onset (ERP data). With EEG ordered as a function of response rate, significant increases in power were found across all standard frequency bands for the pretone data at sleep onset. Significant changes in amplitude were related to decreasing responsivity for all late ERP components except P2. Inasmuch as virtually all EEG frequencies and ERP components were strongly influenced by momentary changes in arousal, arousal must be considered a (possibly the) primary determinant of the characteristics of the overall electrical output of the brain. Response cessation coupled with sharp increases in EEG synchronization mark the point of sleep onset.