Dreams: The Mysterious World Inside Our Minds

Today we are going to talk about why we dream what's going on inside our brains the scientific study of dreaming is called Anaya ology and for most of history it didn't really exist because you can't hold a dream it's difficult to measure a dream you can't taste it you can't see other people's dreams and if you ask them to tell you what they dreamt the results are almost always unreliable in fact it's estimated that we forget 95% of the dreams we have especially within the first 10 minutes of having them.

But then in 1952 something amazing happened researchers at the University of Chicago found this it's a unique type of electrical activity that occurs during a certain stage of a person's sleeping when researchers awoke people during this stage they almost always reported that they had been dreaming also at the same time during this stage people's eyeballs are going crazy rapidly darting all over the place underneath their eyelids you can actually see this happening if you watch people sleep like I usually do during REM sleep some pretty bizarre stuff happens if you look at the electrical activity of a brain that is in REM sleep that almost exactly mimics the way the brain acts when it's awake the biggest difference being that the production of chemicals inside the brain like norepinephrine serotonin and histamine is almost completely blocked and that causes the muscles to stop moving.

Which is why you can dream about flying or running around or fighting ninjas but your body doesn't move people who have a disorder achieving complete REM a topia move around in their sleep and act out their dreams they can even get out of bed and sleepwalk. oh before you move forward I should say two things one is that it's possible to wake up and not be able to move your body because you're still in rem a topia you're completely conscious and you know that you're awake but your body is not ready to move on the flipside you can also be inside a dream and know that you're dreaming this phenomenon is known as lucid dreaming and it's particularly attractive because while I'm in a lucid dream I can conscious decisions about what I do I can go fly to wherever I want or I can have a tea party with Abraham Lincoln I'm in control but achieving a lucid dream is quite elusive.

One researchers were able to deprive mice of REM sleep by using this inverted inside a tub of water way up to the tippy top meaning that the mouse was only able to sit right on top of this little tiny surface when that happens the mouse can still fall into non REM sleep but as soon as they reach REM sleep and their muscles relaxed they fall off the platform into the water waking up what they found was that when mice are not allowed to achieve REM sleep they have an incredible amount of trouble remembering things this happens in humans too.

If you have people remember word pairs and then you don't allow them to sleep the next day their memory for that stuff is incredibly terrible but memory and REM does not stop there if a person learns a difficult new task during the day say a new instrument or a new type of difficult puzzle you can measure the electrical activity in their brain.

While they do that and then while they sleep that night whether they know it or not their brain replays those electronic impulses many popular theories about why we dream are variations on the idea that while we sleep the unconscious part of our brain is busy organizing memories and strengthening connections from the day before that we need in the future

While getting rid of the junk that would otherwise clog the brain now so the theory goes these electrical impulses are detected by our conscious brain and our cortex freaks out and doesn't know what it means and so it tries it's best to create a cohesive story creating a dream this would explain why dreams are often so fantastic and seemingly random they're not supposed to make sense they're not an actual message from our brain it's just the results of our cortex is trying to synthesize the noise coming from all the work being done back in the unconscious under this way of thinking

Dreams are an epiphenomena they're not a primary process that has a purpose instead they're the accidental result of a more important process is going on behind the conscious brain but some researchers don't believe that they believe the dreams serve a primary purpose and that purpose is to prepare us for threats they think this because the most prevalent emotions felt during dreams are negative abandonment anger and the most common of all anxiety the theory goes like this back when we were early humans especially we had no idea what kind of threats we might encounter during the day and so to prepare us our brain would simulate anxieties while we slept to make us better prepared for that feeling in the real world so people who had terrifying dreams were better at dealing with anxiety in the real world and had stronger genes

All right so the theories we discussed today are quite popular but they don't really enjoy a consensus not everyone agrees on them and they barely scratched the surface of scientific thought about dreams but that's kind of the cool thing about dreams think of it like this here is the Eagle Nebula a giant structure in outer space 6,500 light years away but despite its distance we pretty much know what it's made out of we know that it's a hundred trillion kilometres tall we know what caused it and we know where it's gonna be in 750 million years but last night I had dreams and no one really knows why or for what reason and that's pretty cool and that's why thanks for watching if you want to learn more about the world I highly recommend smarter every day it's a show here on YouTube by a guy named Destin who I've met he's awesome I've learned a lot from him he's the guy who did the chicken thing from the Leanback he's also studied what causes poop splash slow motion water balloons and has a lot of guns and explosions what more could you ask for so do me a favor and go check it out and subscribe if you like it and if you haven't seen it yet.