have you ever played a video game for so long but when you finally put on the
controller and are maybe falling asleep you see images of the game flash before
your eyes this 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 weren't falling down I was like why are they all just staying
there I was expecting them to like start as 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 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 shut-eye
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 brains electrical pulses or brain waves
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 brain waves 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 hypnagogic hallucinations are visual or include
weird sensations like fallen 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 low 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 and while 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 hypnagogic hallucination or whether it's something else some
neuroscientists consider it a sleep disorder and speculated might be from
tiny seizures or sudden bursts of electrical activity in the brain
unfortunately 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 hypnagogia is the hypnic jerk or sleep
starts despite the name it's not a hip new dance trend it's an involuntary
twitches jerks are basically just muscle contractions it's kind of like a hiccup
and they're perfectly normal most of the time neuroscientists don't
really know what causes them but they could happen because of the way your
body switches over to being asleep when you're awake you're getting lots of
signals from a part of your brainstem known as the reticular activating system
but come bedtime a cluster of cells deep in the middle of the brain starts 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 the time you don't notice a thing so while this not
what a week not quite a sleep 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 scishow if you want to learn more about weird brain things we
have a whole channel called scishow psychology over at youtube.com slash
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