How can you eliminate dreaming without affecting REM sleep?

Question

The Dreamlands are a vast, alternate dimension that can only be entered via dreams. They are divided up into several sections, all of which are inhabited by monsters who serve the idiot elder god Azathoth. These creatures seek to enter our world and conquer it, using human beings as a focal point.

When a human goes to bed, they eventually enter a mode called REM, which is the deepest and most important mode of sleep. This is where they gain the most rest, recharging them for the next day. Unfortunately, it is also the point that they are most vulnerable. All humans dream in this state, their minds entering the dreamlands for a period of time. This leaves them open to predators, who can consume their minds and inhabit their physical forms, allowing them to cross over into our world and enslave us. This has become more frequent, and these creatures are difficult to kill, slaughtering entire families and communities before being brought down.

The only way to prevent this is to cut people off from the dreamlands by stopping them from dreaming entirely. However, eliminating REM would lead to a lot of irate people getting into fisticuffs in the day due to lack of deep sleep. How can I do this without damaging REM mode?

Answer 1

"Solving" dreaming for humans probably won't protect the world (though having your protagonist try it and fail for this reason might make a very entertaining story twist).

The reason is that all mammals undergo REM sleep and dreaming. Just watch a dog or cat take a nap if you don't believe me. Dogs, cats, monkeys and apes, barnyard animals like horses, cows, pigs, sheep, and their wild cousins, all dream. And based on the way dogs and cats twitch and occasionally vocalize, their dreams aren't always about pleasant things -- "fighting bears" is the way my partner describes the Rotweiler's sleep-barking and such.

If Azathoth's minions can't get through to our world via humans, why wouldn't they be able to get through via dogs or cats, of if those aren't quite "conscious" enough, monkeys or apes? One might hypothesize that some minimum level of intelligence is needed, with cats, dogs, pigs, goats, and horses (including donkeys and mules) being the only domestic animals smart enough to supply a portal -- and all of these are pretty good at defending themselves in their dreams.

Answer 2

REM Sleep is sleep characterised by the eye movements that occur during dreams, if a person has no dreams they won't experience any Rapid Eye Movement. Without dreams REM Sleep would become a thing of the past. Without dreams people would start to deteriorate and probably eventually die the same as people who suffer total sleep deprivation but slower.

You could posit a change to how the brain processes and stores memory, thus eliminating the need for that state of sleep in which case people still need the body rest of the other 3 stages of sleep but no longer need REM sleep. This would probably result in people sleeping an extra cycle of N1-N2-N3-N2-N1 sleep to compensate for the lost REM stages, this may result in waking at unusual times in the sleep cycle. There'll be an adjustment period as people adapt to getting their sleep interrupted in stages they're not used to, like their alarm going off while they're in stage 3 deep sleep instead of the much lighter stage 1 sleep they're used to will make getting going for the day really hard for a time.