Alright. So in this video, we're going to be going over those stages of sleep and talking about what EEGs look like for people who are awake in the different phases of non-REM as well as in that REM phase. Alright. So we're going to begin with people who are fully awake, so people who are fully conscious, not even beginning to sleep yet. And in people who are awake, we see a really characteristic EEG pattern called beta wake.
And I always remember that beta means awake by thinking about busy beta waves, that kind of busy, active, fully conscious brain, right? We have our busy beta waves, and these tend to be pretty high frequency. So we're going through a lot of wave cycles per second but relatively low in amplitude. So you can see we're not having any like really high amplitude spikes or anything like that happening with our beta waves. They're staying pretty low amplitude, they're pretty small, but pretty high frequency.
We're seeing a lot of waves per second. So those are our busy beta waves. Now from there, we would drop into stage 1 sleep, and stage 1 is considered a very light stage of sleep. Like if a person tapped you on the shoulder you'd probably jerk up immediately and say I wasn't even sleeping, you know, like that kind of that twilight phase before we really get to sleep. So in stage 1 we see a characteristic EEG pattern called theta wave.
So I always think, in contrast to our busy beta waves, we have our tired theta waves or kind of our twilight theta waves. You could also think of like any of those t words kind of going together. And theta waves are basically just going to be lower frequency than beta waves. So you can see the amplitude hasn't really changed, it's still pretty low amplitude, but things are kind of slowing down so we're seeing fewer waves per second basically. So they're just lower frequency than beta waves.
So our tired theta waves are going a little bit slower than our busy beta waves were. Alright, from there we go into stage 2, and stage 2 is considered moderately deep sleep. You are well and truly asleep at this stage and stage 2 actually evidences 2 very characteristic bursts of activity. So the first is called sleep spindles, and sleep spindles are little bursts of extremely high frequency activity. So if you are looking at our EEG here you can see our sleep spindle right there is really high frequency compared to the EEG on the left or right of it.
To me, these almost look like the EEG kind of gets, like, squished together a little bit. So it's like this is this little tiny pocket of really, really high frequency activity where we're seeing a lot of waves per second. So those are our sleep spindles, very high frequency. Now we also have K complexes, and K complexes are basically very high amplitude spikes, and these really stick out because as you can see for the majority of our EEG here our amplitude is pretty like low to moderate, it's not spiking really high, so these K complexes really stand out because they're these super, super high peaks that you'll see in stage 2 sleep. Alright, so in stage 2 we have two characteristic bursts of activity, our high frequency sleep spindles and our high amplitude K complexes.
Alright, from there we would go into stages 3-4 sleep, and stages 3-4 are considered very deep sleep. So it's very difficult to wake up a person who is in stage 3-4 sleep, and both stage 3-4 sleep show delta waves on an EEG. So I always think of kind of deep sleep delta waves, those d's kind of going together, and these really stand out compared to all the other ones because they are very high in amplitude. They're going to be our lowest frequency, that we're going to see, so they're kind of pretty slow, but they're really high in amplitude very consistently. So you'll see a lot of, like, these really, really tall peaks with delta waves, very consistent on the EEG and much higher than what you would see in any other type of wave except for those K complexes in stage 2.
So we have our deep sleep delta waves, nice tall peaks there. And then finally, we go into REM. Of course, in REM we would have our dreaming, that kind of partial paralysis, as well as that slight, like, physiological arousal, so our increased heart rate, increased respiration. And very interestingly, REM EEGs really resemble beta waves. So they basically resemble being awake, and we're actually going to talk about some kind of more like conceptual or theoretical reasons as to why we think that may be when we talk about dreaming a bit later in the chapter.
But as you can see, these REM EEGs are relatively high frequency, not quite as high frequency as we saw and our beta waves are not identical by any means, but they are pretty similar and you can see they're also pretty low amplitude. We're not seeing any really high spikes with our REM EEGs. So REM and our awake beta waves look the most similar out of all the EEGs we would see with our different sleep stages. Alright. So just to kind of sum everything up, as you can see here we have our busy beta waves that we have when we are awake, very high frequency, lots of brain activity happening when we are awake, of course.
From there we go into our tired theta waves, things are kind of slowing down. We're lower frequency than before. In stage 2, we have our 2 characteristic types of activity, those high frequency sleep spindles, and those high amplitude K complexes. In stage 3 and 4, we have our deep sleep delta waves, right? Everything is kind of slowing down, lower frequency, and really really high amplitude spikes pretty consistently in that EEG.
And then finally, we have our REM EEG which looks fairly similar to what we see in our beta waves, so pretty low amplitude, relatively high frequency. Alright. So those are our different sleep stages and their characteristic EEGs, and I will see you guys in our next video. Bye-bye.