One caveat here is that sleep was recorded at night, but intake was at noon, so we don't know what really would have happened if they had been recorded during the afternoon, possibly they wouldn't go to sleep, at least that is what Jordi observed, but we also don't know what would have happened if they had taken ayahuasca at night, which often occurs during rituals, so this is an open interesting question: is REM sleep reduced many hours after intake, as a rebound of something that was increased before? 