REM sleep intensity tracks a brainstem hub's activity while you are awake
Stronger locus coeruleus responses during a demanding attention task went with more theta energy in REM sleep, and with a burst of sigma activity in the moments before REM started. In older adults the pattern reversed on an easier task, hinting that a balanced level of daytime activity, rather than simply more of it, may suit REM best.
For you: Nothing to change tonight: this is a first look at how waking brain activity and REM sleep move together, and it offers no lever a reader can pull.
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