你有没有过这种情况 玩了很长时间的电子游戏 放下游戏手柄
Have you ever played a video game for so long that when you finally put down the controller,
and or maybe fall in a sleep, you see images of the game flash before your eyes?
This has happened to me a bunch of times personally.
One time, I had played so much tetris,
and I was writing a paper in college,
that I got surprised that the words on my screen were falling down.
I was like:”Why are they all just staying there?”
I was expecting them to like start
I was very tired.
These hallucinations can be other things too,
like jigsaw puzzles or apple-picking.
And they happen in the weird limbo between wakefulness and sleep called hypnagogia.
In fact, lots of strange things can happen in this state,
like twitching or something called exploding head syndrome.
不要担心 大脑并没有参与这个过程 但是那仍会让你产生幻觉
Don’t worry. No brain bits are involved in that one but it can still get pretty trippy.
Scientists don’t know a ton about hypnagogia, but they are learning.
They consider it to be an altered state of consciousness, not unlike an LSD trip.
The hypnagogic state only lasts about 10 minutes,
as you transition from being awake to being asleep,
although sometimes it’s called the first stage of sleep.
And during this period of drowsy pre-slumber, you can hallucinate.
You might feel like you’re falling, flying or floating.
You might hear short phrases or sounds
or see anything from amorphous shapes and colors to clear images of people.
Now this might seem like dreaming but it’s a little different.
Most dreams happen during rapid eye movement, or REM sleep,
where your brain is much more active than during the rest of your shuteye.
And dreams are usually pretty vivid.
You’re part of some kind of action or story,
like going to outer space in a hot air balloon
to meet a clown that sounds like Sir Patrick Stewart.
But hypnagogic states are more like watching snippets of films in an experimental art gallery.
Salvador Dali even famously used hypnagogic imagery to inform his art,
disrupting his naps to get inspiration.
It’s not always the case,
but the imagery can come from something mundane or repetitive you were doing while you were awake,
like playing tetris.
That’s why this hallucination phenomenon is sometimes called the tetris effect.
Scientists don’t know why these hallucinations happen,
because not everyone gets them and they can be a symptom of disorders like narcolepsy,
which is basically extreme sleepiness.
But one idea is that some parts of your brain take longer than others
to fall into sleep mode.
As you’re drifting off,
your brain’s electrical pulses, or brainwaves, start to slow down
They shift from moderately fast alpha waves,
which are typical of being relaxed but awake,
to slower theta waves of early sleep,
to even slower delta waves of deep sleep.
But the slowing down isn’t even.
EEG measurements of brainwaves suggest that
your brain puts on the brakes faster in the front than in the back.
And that means that the parts of the brain in charge of vision or balance could be active for a bit longer,
which might explain why so many hynagogic hallucinnations are visual,
or include weird sensations like falling.
And because your frontal cortex is snoozing during this in-between state,
it can’t help you sort out what‘s going on like it normally does.
One of the most frightening things that can happen during this drowsy lull
is hearing a loud, exploding sound like a cymbal crash or gunshot.
Sometimes there’s also a flash of light.
This is called Exploding Head Syndrome.
虽然这不会伤人 但是同样是很可怕的 它会将人们从半睡半醒的状态惊醒
And well, it doesn’t hurt, it can be so scary that it wakes people up from their half-asleep state.
It’s not clear whether this is just a specific type of hynagogic hallucination
or whether it’s something else.
Some neuroscientists consider it a sleep disorder and speculate it might be from tiny seizures,
or sudden bursts of electrical activity in the brain.
Fortunately, most people who have this problem aren’t as bothered by it
once they find out that it’s not a sign of something more serious, like brain cancer.
Another thing that can happen during hynagogia is the hypnic jerk or sleep start.
Despite the name, it’s not a hip new dance trend, it’s an involuntary twitch.
These jerks are basically just like bustle contractions, kind of like a hiccup.
And they are perfectly normal most of the time.
Neuroscientists don’t really know what causes them,
but they could happen because the way your body switches over to being asleep.
When you are awake, you are getting lots of signals from a part of your brain stem
known as the reticular activating system.
But come bed time, a cluster of cells deep in the middle of the brain
start to block these signals and bring on sleep.
While this setup makes for a pretty good transition to dreamland, it’s not entirely seamless.
So hypnic jerks could be glitches that arise during this process.
The twitches might be related to some aspect of your hypnagogic hallucinations and they could wake you up.
But most of the time, you don’t notice a thing.
So, while this not-quite-awake, not-quite-asleep state can be pretty freaky,
usually it just passes you by,
which is probably good, because you have to go through it every single night
and not everyone wants to be as surrealist as Dali.
Thanks for watching this episode of Sci-show.
If you wanna learn more about weird brain things,
we have a whole channel called Sci-show psychology
over at youtube.com/scishowpsych.
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