In 34 healthy younger adults and 18 older adults, stronger activity in the locus coeruleus (a small noradrenaline hub in the brainstem) during a demanding top-down attention task was associated with more intense REM sleep, measured as theta oscillation energy on sleep EEG, and with more sigma oscillation power in the moments just before REM began. In the older adults, the association ran the opposite way during a simpler bottom-up task, which the authors read as a sign that a balanced level of daytime activity suits REM sleep best.
- Study design
- Study
- Journal
- J Biomed Sci
- Evidence
- preliminary
What it shows: Early, mechanism-level work: brain scans plus overnight sleep recordings in 34 younger and 18 older healthy adults, which lines up two measurements rather than showing that one causes the other. The direction of the link flipped depending on which task people did, so it is far too unsettled to read as an explanation of anyone's bad night.Study · J Biomed Sci