Eeg and Autonomic Response Pattern During Waking and Sleep Stages

Abstract

The response hierarchy of EEG and autonomic variables to tones of increasing intensity was studied during waking and sleep stages 2, REM, and SW (3 & 4 combined). Tones of 1000 Hz (5 sec duration, 55 sec ISI) were presented to 35 young adult male subjects. During waking, the tones began below awake auditory threshold and increased by 5 db until a motor response (button press) was made. During sleep, tones began at awake threshold and went to arousal threshold, i.e., motor response and/or an EEG change indicative of arousal. Changes in EEG, finger pulse amplitude, heart rate, skin potential, skin resistance, and respiration period were measured for each stimulus and were compared to a pseudostimulus response scored 25 sec prior to the actual stimulus. In the awake state, statistically significant responses (p < .05) were found for EEG, finger pulse, heart rate early deceleration, skin potential, and skin resistance to the tone at awake threshold, but not to tones at lesser db levels. During sleep, significant EEG responses were present to tones 30–25 db below arousal threshold, finger pulse 20–15 db below, and heart rate acceleration 20–5 db below. Significant skin potential, skin resistance, and motor responses were seen only at arousal threshold. Thus, in sleep, in contrast to waking, there were clear responses to stimuli below the arousal threshold, and there was definite ordering of the appearance of the various responses: EEG preceded the cardiovascular, with electrodermal and motor occurring only at arousal. This order was constant over sleep stages. Arousal thresholds were very similar across sleep stages in day sleepers (approximately 35 db above awake threshold). The threshold during stage 2 for night sleepers was about 15 db lower than that for day sleepers.

Effects of train noise and vibration on human heart rate during sleep: an experimental study

“…In a similar study dealing with traffic noise alone, Griefahn et al 11 found an increase of HR matching our initial response but no delayed increase. A similar initial increase of HR has been found for pure tones during sleep 36. We propose that the second plateau is due to the additional vibration exposure, which seems to either act in isolation to result in cardiac response, or alternatively enhance or interact with any delayed effects of rail noise on HR.…”

Cardiovascular responses to railway noise during sleep in young and middle-aged adults

“…Meanwhile, the HRL decreased in a dose-dependent manner. Such a result has been reported many times even in sleeping subjects (Keefe et al 1971;Berg et al 1975;Muzet 1980;Muzet et al 1981Muzet et al , 1997Di Nisi et al 1990;Hofman et al 1995;Carter et al 2002;Basner et al 2008) suggesting a protective mechanism even during sleep which warns the sleeper against a potential danger. This is also reflected by the fact that arousal responsiveness increased with sound level (Saremi et al 2008).…”

Enhanced awakening probability of repetitive impulse sounds

“…As a result, the data do not allow a direct comparison with EEGawakenings as defined in Basner et al (2004). In a study on the response hierarchy of EEG and autonomic variables to 1000-Hz tones, Keefe et al (1971) reported that some of the 35 subjects were clearly awakened by the tone, as indicated by EEG activity, but failed to press the micro switch to the arousing tone within 60 s. This occurred more often when the subjects were awakened from slow-wave sleep. In various sleep studies, Lukas and colleagues directly compared response frequencies for (1) sleep stage changes, (2) arousal of at least 10 s duration, but without the use of the "awake switch," and (3) arousal of at least 10 s duration with use of the "awake switch."…”