The article says it "increased the length of N2 sleep, a form of non-REM sleep that takes up about half of a good night's rest." Presumably this is at the cost of REM sleep? How is this then a good thing?
It could also mean shorter N1 or N3 phases of non-REM sleep. From my limited understanding it seems like the subjects falling asleep faster would correspond to a shorter N1 phase, but I haven't read the paper yet.
