Date of Award

Summer 1996

Document Type

Dissertation - Restricted

Degree Name

Doctor of Philosophy (PhD)


Biomedical Engineering

First Advisor

Myklebust, Joel B.

Second Advisor

Ackmann, James J.

Third Advisor

Goldstein, Michael D.


It has been understood for several decades that electrical potentials associated with activity in the central nervous system (CNS) can be recorded from the scalp. It has also been known for at least sixty years that variations in heart rate are mediated by the autonomic nervous system (ANS) and partially modulated by the CNS. While electroencephalograms (EEG's) have been widely studied since their discovery, systematic analysis of heart rate variability (HRV) is a relatively new science. Despite different origins and historically disparate methods of classification, spectral analysis has shown that both EEG and HRV exhibit characteristic rhythmic responses to changes in physiologic state. Preliminary experiments by the author further demonstrate that both EEG and HRV exhibit rhythms which coincide with respiration and variations in blood pressure. Since EEG and HRV share frequency components and because ANS activity is modulated in part by the CNS, it seems reasonable to inquire whether CNS-ANS coordination can be measured with covariance properties of EEG and HRV. One simple measure of spectral covariance is the coherence spectrum, a frequency domain? value. The notion that EEG-HRV covariance relates to CNS-ANS coordination would be further supported if covariance properties were found to respond to changes in physiologic state. Two physiologic states which every normal person experiences on a daily basis are slow-wave sleep (SWS) and paradoxical sleep (REM). Consequently, this study examines characteristics of EEG-HRV coherence in SWS and REM of healthy young adults to demonstrate and begin to interpret changes in CNS-ANS coordination during sleep.



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