Found that REM activity occured on average every 92 minutes.
Also found that this was when they were more likely to be having vivid dreams.
Supports the timings of the sleep stage cycle.
Suggests an endogenously controlled cycle.
Dement and Kleitman (1957)
Found that although alcohol aids sleep, it leads to a more fragmented cycle during the sleep stages.
In particular, alcohol has been shown to lessen the ammount of time spent in REM sleep.
Suggests the ultradian rhythm of the sleep stages can be changed by a great deal by external factors that are allowed to consume and influence our EPs.
