Arousal thresholds during human tonic and phasic REM sleep.
Level 4 - case-series / case-control
Within-subject observational physiological study without a randomized intervention.
PubMed 20477954 · doi:10.1111/j.1365-2869.2010.00831.x
What was done
Researchers measured behavioral arousal thresholds in response to external acoustic stimuli during tonic and phasic episodes of rapid eye movement (REM) sleep in humans, and compared the electroencephalogram (EEG) frequency spectra of these sub-states to non-REM (NREM stage 2 and stage 4) sleep stages.
What was found
The abstract reports no numerical values, sample sizes, or test statistics. Directionally, behavioral arousal thresholds differed between the two REM sub-states: arousal thresholds in tonic REM were not different from stage 2 NREM sleep, whereas thresholds in phasic REM were similar to slow-wave sleep (stage 4). EEG frequency spectra were more similar between the two REM sub-states than between REM and NREM stages that had similar behavioral thresholds.
Why it matters
The findings provide evidence that human REM sleep is not a uniform neurophysiological state, showing that sensory responsiveness to acoustic stimuli is substantially more gated during phasic than tonic REM sleep.
Limits
The abstract does not disclose the sample size, participant demographic characteristics, stimulus parameters, or any quantitative data or confidence intervals.
Cited by
- context Arousal thresholds are higher during slow-wave deep sleep than during stage 2 sleep or REM sleep, making it easier to awaken from stage 2 and REM.