Are Your Eyes Part of Your Brain?
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- Опубликовано: 8 сен 2021
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When you think of a brain, you probably imagine that pink, wrinkly organ in your skull, but we don’t have to stop there! Neither the brain’s functions, nor its cells, are confined to the organ we normally think of as the brain.
Hosted by: Anthony Brown
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Sources:
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Images:
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You know what, I love Scishow. So many science channels have become clickbaity and more for entertainment. You guys truly teach us something more, and I absolutely appreciate it ❣️ You guys are amazing!
PBS is really underrated and Kurzgesagt too
Lol then there's people that will be like "omg there was an ad before the video CLIck bAIt"
If you like this! you should watch TedEd! They are very similar!!
Yes.
Edit: I say this because I had a brain tumor as a kid that messed up my vision by crushing the optic nerve. I've been frustrated by the lack of interdisciplinary research between optomology and neurology. Cool video tho
My step dad had brain cancer that made him go blind, but he didn't even realise he was going blind... He just thought he was having balance issues. He just legit lost around 60% of his field of view, and didn't realise it.
I didn't even know that was a possibility, until then. 😳
@@Acidfunkish did his vision starting to loose when you got to about his brain cancer
@@akashdeepsingh7506 what???
@@demonflowerchild i was asking about early signs
That's a bummer, and I know what it's like. I came out of surgery to remove a pituitary tumour and now my left eye only half works. It might be neurological, it might be vascular, the surgeons can't tell.
"The eyes aren't protected by the skull."
Brow: "Am I a joke to you?"
Who else has eyelids made of solid bone?
😅
Thing hitting eyes head on: "Yes you are"
@@ChemEDan definitely not me😂😂😂
The retina is considered an extension of the brain. I wouldn't call the retina "brain" but it is part of the central nervous system, alongside the brain and spinal cord. And there is a lot of research into using the retina as a diagnostic tool for neurological disease
Thank you! The NS has a name for a reason...althought it's not part of the CNS, more likely part of the PNS
Based on that, I feel like a “soft” definition would be that the brain has to have some manner of internal “calculation” to it. That is, if the nerve cells in this area are “read only”, they’re not part of the brain.
that would exclude some neurons inside the skull
Don't confuse the convention and language of reality with reality itself.
Our bodies are not endlessly smaller constituent parts. Reality is not static atom->molecule->organelle>cell>tissue
The skin is a barrier as much as it is a connector. The eyes are the brain as much as the brain is the eyes.
But every single neuron is a small calculator in itself, having inputs and output.
The brain is the most central part of the wider nervous system, that at some point connects with it, without "being" it. This questioning is kind of funny to make us think somewhat "surprising" things like how in a way "part of our brain" literally touches molecules of something putrid you have the bad luck to smell, but has really little practical purpose otherwise. In a way it's a bit like questioning whether the clavicles and shoulder blades are also part of your arm, that's kind of buried in your thorax. It may take you into curious investigations of the anatomy and evolution of such structures, but in the end your arm is your arm and your torso is not.
@@redsnake69 ish
I would say it matters more where it originated that trying to rigidly define it.
Most likely eyes were light sensing spots on a more prototypical version of the brain of many land dwelling animals so yes, they're part of the brain in those cases.
Yeah I'm not understanding how the way we define the brain would have practical impacts. The classifications we humans like to come up with are pretty arbitrary.
I'm really enjoying our host Anthony Brown's delivery. And thanks to the rest of the team putting this topic together.
As someone with a mental illness, I am always pleased to see more about the interplay of the brain and other important neurological features and the rest of the body. Thanks again for a great video.
Having sight issues and neurological issues and just interested in brains, this was really informative and easy enough for me to understand when I'm tired. Thanks, SciShow!
My whole body is a part of my brain!..🧠
Well not really. Your body is controlled by your brain. Your body is not you. Your brain is you.
Do you really think you're just your brain? A brain can't exist separated from your heart, liver, stomack, etc, and it's constantly interacting with It and not only controling It but getting controled by it's demands. Also, a most of what happens on your brain is completely outside of your awareness.
I mean if you wanna think about it that way!!! 😄
Woah! SPOILER ALERT! 🚨
@@scottcupp8129 your nervous system inside your skull is not the sole part of you that results in a sense of self. Lots of research on this.
Since becoming a gemmologist, I have understood the potential our eyes (and, therefore, our brains) have. It's incredible!
Edit: thank you for all the likes! I meant by understanding things like the types of lustre/luster.
I think something might be wrong with yours, if it took you studying gems to realize this ....
I like this quite a lot
@@xTheDeerLordx please don't be hostile and mean. It's not a good look.
@@noctiluca4580 well you do need your eyes to find them don’t you
@M Obviously, I know how to use my eyes. I meant by using what I learned in gemmology (how lustre can give you an idea of the refractive index, understanding and seeing the types of lustre) and applying it when using my eyes.
A brain is the only organ that named itself.
Aren't eyes developmentally formed from brain tissue though? Or part of the eye at least. So that part should be considered part of the brain, I think.
I was just explaining this earlier today. Loved this.
Grant us eyes... Grant us eyes...!
It's always good to have eyes on the inside.....
Didn’t expect to see a fellow Epica fan here! Nice!
@@Im_Just_A_Dreamer @TheLegendaryDreamer2 Me neither, heh... Mark Jansen has a master degree in Psychology, so maybe he's watching SciShow Psych videos too... 👀.
This is a great well explained video and really interesting
This is fascinating. I wonder if nerve endings could be considered extensions of the brain seeing how some stimuli such as being burnt will produce a reaction to move your hand faster than your brain can process what had just happened.
Maybe the key word was at the end there "Brain-system", similar to how we view (central) nervous system etc, . It's not just one thing but a system of things.
This is gettin' really close to the philosophy of language and meaning and what physical things constitute particular words etc
developing eyes in mammals, cells of brain and skin (epidermis) tissue intermingle with each other.
also in the eyes there are nerve paths not only for vision (visual cortex), but also paths to the Pineal gland for adjusting the inner clock. To say eyes are part of the brain is not wrong minimum in parts.
on top don’t forget the “gut brain”, the nerves aggregation around and controlling the digestive system…
I'd use the definition where the mammalian brain is contained within a mammal skull. As far as I'm aware, all mammals share the same basic "framework" for a body. Brains may be implemented entirely differently in non-mammals, but in mammals it's pretty clear which part does the major processing. As far as I understand, there are neurons in the spinal column too which are related to reactions (if you burn your hand, you pull it away from the heat source faster than your brain can respond), but I wouldn't consider them as part of the brain.
I would consider spine neurons as part of brain. I go with option 1, neurons = brain
The brain and spinal cord are considered two distinct things, but together are considered the central nervous system. (All the other nerves that go to muscles and such are part of the peripheral nervous system)
You are exactly showing a bias that things like hominids have are more true. There's no actual truth to that, not even within mammals. It's an almost invisible hindrance to understanding (not to all scientists though thankfully).
@@Megan-nt7dm that's a hominid central understanding that gives an almost invisible bias to understanding. Only the most open scientists avoid this bias.
@@PatrickPoet I'm just stating the current definitions in the field, most scientists are old/set in their ways. This sort of stuff has no bearing on my work anyways, I don't even care too much about neurons, I work in glia. Glia are honestly insanely important, as neurons can accomplish nearly nothing without them.
Paraphrasing Alan Watts: we're pretending that our language conventions are reality. We separate 1 non-dual thing into two, forget that we did so, and then are confused about it. The result is asking nonsense questions like "are eyes part of the brain?"
Next: "is our inner subjective experience part of the universe?" Kind of silly and click-baity, but nevertheless could have interesting and informative material about "qualia" and monism/dualism and its varieties.
How am I gonna be candy flipping cluck this video and a comment about Alan watts is near the top that's cool as hell
@@captaincrunch6113thats why life is beautiful
Hope to see a SciShow Tangent episode on brains!
Thank you Sci Baba.
Anthony reminds me of Levar Burton for some reason. It kinda makes me nostalgic.
There's the wider "nervous system," and in organisms with "centralized nervous system," there's the "central nervous system," AKA spinal cord + brain, the latter being most massively centralized clump at the end of the cord, that centralizes much/most of nervous processing. The most interesting and disturbing thing of how part of the sensorial systems in a way are also the brain was left out: when you smell something stinky, putrid, disgusting, molecules of this repulsive matter are actually "touching your brain."
I don't find that disturbing
You rods&cones are behind eye muscles maybe their cells that transmit general light
So zombies would really like eating octopus legs. Neat.
Very interesting!
1:35 well that probably would explain
human reflexes if they are not necessaryly a conscious reaction
Wrinkles of brain and Look a polyps wonder if brain coral functions as actual brain
Do we have neurons in or muscles that send information to the brain
How do we know what animals capable of if we don't know what part brain does what or how complex a concept is
We don't necessarily need to define brain
Some things just can't be precisely defined
Like life
_"Brain and brain!_ *What is Brain?!?"*
(Excerpt from _"Spocks' Brain"_ Star Trek, t.o.s.)
Please don't make me remember that episode.
Your brain has perfectly perceived the thoughts in my brain. Crazy brains, amirite?
@@joebaumgart1146 ....................sorry.
Based on how you talk about the brain it can be summarized to the main place of processing of information and the decision making as a consequence.
This definition is working both for the human traditional brain and the complex nervous network of octopi.
"Dominant cluster of neuronal tissue" works for me. It's only confusing if you think all of your decisions happen only in the brain.
Even "dominant cluster" leaves out lots of stuff in lots of animals (and other things) that clearly show effects as if there's a brain at work. It's a blind spot that makes it hard to see the truth about how things work across species. Luckily, some scientists apply the scientific method and discard things, no matter how obvious, that aren't supported by, or are contradicted by evidence.
Taught my eyes calculus... they're such promising pupils
Ha!
Yes. Because they're one of the senses that can let you see everything and sometimes it can can give you some strange dreams or some can give you a response to other things you can experience.👀😍
im going to say yes, due to how eyes in cordates evolved
The brain is the squishy wrinkle sack that pilots it’s flesh mecha prison.
Neurons can be up to a meter long. That blew my mind. Single cells in my own body that big. Shivers.
Better option would be to start thinking of Nervous Systems instead of brains, because things are neither that simple nor that clear cut and separated.
this
Half of scishow and western science is just pretending that semantic conventions are reality. Separating 1 thing into two, forgetting that we did that, and then being confused and asking nonsense questions like "are eyes part of the brain?"
@@infra_Gray oh shut up already, stop spamming that stupid quote
Only 15 retries before I got to watch without an ad. Not bad.
Everything is part of my brain.
As you once did for the vacuous Rom, grant us eyes! Plant eyes in our brains to cleanse our beastly idiocy!
This guy said brain more than a zombie in a 70’s horror film
My nose is part of my brain, I can be stimulated to any range of modality depending on the scents reaching me: I hate old-people-smell, I love girls-room-smell; there are a dozen other things'-scents that illicit emotional involvement on some deep level. I get a range of opinions based entirely on nose.
would you think that an appropriate cut off point is the Central Nervous System?
Cool vid
..... Before I even watch the video...
"I can live without my eyes, but I can't live without my brain"....
my eyes think theiy ARE part of my brain.
but my brain isnt so sure about it
isn´t the brain just part of the central nervous system (CNS)- which also contains the nerve bundles in the spine. I mean, the nerves got to do their job from somewhere, and when the axons can be up to 1m long, that means that the nerve cells in our feet, fingertips etc are probably not directly connected to the brain, but to the spine, from where the signals get transferred upwards. So we also have a peripheral nervous system (PNS).
No idea how physicians define it, but I think the brain (in the skull), the brainstem and the spinal cord are CNS, whereas the rest is PNS.
I think we should make a distinction between vertebrates and invertebrates, because the also don´t have a heart like we do, nor do most of them have a closed circulatory system.
Brain: organ capable of inducing feedback systems.
Which animal has it's eyes furthest from their brain? We could probably learn what a brain is from that (I suspect an animal with eye substantially further from their brain would develop a dense cluster of nuerons that are essentially mini brains only capable of interpreting visual information)
Octopus? Brain all over the place
What a nice hypothesis that can lead to tests and thus lead to more understanding. Good on you. You have the instincts of a good scientist.
@@PatrickPoet Thanks Patrick :) I started reading your comment and was pleasantly suprised to find that it was not patronizing, but instead very supportive. You rock :D
@@hacked2123 ty
Thinking abt neurons in your fingers makes playing string instruments make more sense? Like, It doesn't feel like my hand moves on its own, but it does feel like... I don't know how to describe.
What about the enteric nervous system? It has been refered to as a second brain.
Yes!!!
Your brain is connected to your entire body. It's a big system. The question is strange.
We're all just a bunch of brains asking what we are.
I propose as the definition of a brain: A dense clump of neurons that has self-sustained neurochemical transmissions that are not necessarily attributable to stimuli (thought?) and provides a response signal when given external stimuli (fight-or-flight).
With some quick rationale I would break the problem down like this:
A brain is a type of a thing that I would call a neurocenter; a dense collection of neurons which performs complex processing on information and can do so quickly due to the dense clustering.
A brain is specifically a type of neurocenter which interfaces with and does most of the complex processing for most, if not all, of the other parts of the nervous system, especially those tied to sensory and action organs.
You could also say that a neurocenter would need to be located physically close to many of an organism's sensory organs to qualify as a brain, kind of like how a human brain is located close to the eyes, ears, nose, and tongue.
This would mean that an animal like an octopus doesn't have a proper brain but it does have several powerful neurocenters.
It gets a lot more wibbly wobbly when we say what a brain does, or what a brain accomplishes, and then see those same effects in creatures that don't have a neurocenter. You've stated a good hypothesis, but there is evidence extent that contradicts your hypothesis. What do you do next? If you follow the scientific process, you may too be a scientist. If you cling to it in the face of evidence to the contrary, it will keep you from learning.
@@PatrickPoet While you're not wrong in a lot of ways, I was more proposing a useful definition for A Brain, based on what the word is generally used for, rather than trying to specify necessary characteristics of a system that performs brain-like tasks. I probably should have specified as such.
With that specified, yes, there are creatures with neurological systems that don't have a central neurocenter or even any neurocenters but they can still perform complex processing. By what I'm proposing we would say that those creatures just do so without a brain or neurocenters respectively.
It's kind of like how nails and screws perform the same basic task, and can even look similar, but do so in ways that, while similar on the deepest level (friction), are still different in ways that are important enough for us to give them different names.
Isn't this just the different between CNS and brain? Because it feels like CNS and brain are useful definitions. All animals (that I'm aware of) have a CNS, but not all have a brain. A very dense cluster of neurons heavily localised is basically a brain, but a CNS both contains the brain and the diffuse neurons around the body of the animal.
. . .seems to me this question could easily be answered by the human connectome project, it was supposed to be completed by 2017, could you see if the peripheral nervous system couldn't be speaking with a mini-brain that is in the spinal collumn? Simple reflex decisions would be easy to wire through practice and with the cells being plastic enough to remember some hardwired reflexes through genetics: and that leads me into the question -- How much of our intelligence is related to genetics and how much to education?
Arguably missed the most important definition of a brain - the part of your body that zombies eat after the apocalypse.
Where the brain ends has been messing with my head for years as a hobby AI nut. If we can't draw the in/out line on people how will we do it with computers?
I think you entire nervous system is brain you experience your nervous system.
Maybe call it "brain system"? Like how the neuro/nervous-system includes the brain, spine, and nerve cords/endings. The brain system would include the brain, eyes, heart, and sometimes fingers/limbs
Scientists also say we have a gut brain, which I assume refers to a mass of neurons
Id say its tissue in witch signal processing happens
Where the brain begins and end complete depends how we decide to define "brain".
If everyone dies of neurological asphyxiation all you have to do is deprive individual human parts and only the ones that lead to death after being deprived of oxygen could then be be defined as part of the brain. This would then include only the vital organs and the brain itself as loss of liver, kidneys, heart, lungs, etc. would all be direct participants in the process of living but as some or all of these organs can be replaced with or by mechanical means then they don't even qualify as parts of the brain. So in essence only the brain is the brain as an individual or creature is generally only veiwed as dead when the brain ceases to function, or is brain dead, and is further demonstrated by the fact that the rest of the body can be kept alive by artificial means, long after the brain has stopped all function. I may be wrong but if so hopefully i will learn something knew.
Soo... you saying that Octopuses uses "Ultra Instinct" all the time, NICE
Don't our guts have neurons in them too?
Wait, if dopamine causes alertness, how do people with what we think is dopamine deficieny stay alert all day? I have ADHD and have an inability to nap or sleep during light hours. If I had a decreased level of dopamine, wouldn't I be sleepy all the time? I'm confused.
Same. Been thanking about this so much. One adhd medication made me so sleepy though.
if i took a shot for every time you said brain... id be dead
Is it weird that I know the answer from anime? The character had a serial number on her eye (aka her body), so she was supposed to have the original brain in a clone body. Then they revealed that the eyes were transplanted with the brain bc of the neurons involved, so she was actually the cloned brain and not the original.
If you want to keep the definition of a brain, you could say that it is the part of the body that contains neurones that are in charge of processing the most high functions of consciousness. Though I agree that it is still unclear if some of these functions are handled in other parts.
I go with neurons = brain
@@WhoAmi2357 The reason we differentiate parts is because it is convenient to do so. If you hit the nerve in your elbow you don’t say “ouch my brain hurts”
the thinky part
Try on this definition: a brain is the tissue with the highest density of neurons in the body. Not sure why this is so hard. Also no mention of the neurons in the gut? Also, everything on YT is "click-bate".
Not watched the video yet but makes sense... in a way... they must be.
This is where I think analogues are helpful. Think about a computer. Most would say the "Brains" of the computer is the CPU. Makes sense because that's where most of the computing is actually done, but it's not the only place. There are logic processors in just about every component of a PC, such as the GPU, memory controllers, sound cards, etc. They all connect back to the CPU for coordination and direction, much like your fingies are connected by nerves back to your head. I'd still say the mass of gray matter in your head is your brain even though it's wired to other computational systems. Animals like caterpillars and hydra are more specialized, so don't have a CPU, like your car's key fob doesn't have a processor. It has logic elements, but no centralized brain.
Just until retina
Yeah, your brain starts around where your optical nerve is. And that's the easiest line.
You're missing the point that we don't actually know. What you've stated as a fact is a hypothesis. What tests could we apply to support or deny your hypothesis?
@@PatrickPoet Well, in terms of anatomy, a brain is just an object that people have observed, recognized, and named when doing dissections. The tests you would apply would be doing more dissections to see if you find more brains. But that's a settled question that we do actually know the answer to (and have known at least since the time of Galen, and probably longer). If you're saying we don't actually know, you must be thinking of some other definition of what a brain is. But the anatomical definition is the normal one, and it's totally straightforward.
Why is the script writer not credited in the description?
no, its like saying ears, nose, and mouth are part of the brain. eyes don't think they simply gather information from light and send that information to the brain to process
What about the cat brain in our stomach? You should talk about that.
Octopuses have a 'distributed' brain: that's basically accepted. Mammals, including humans, have nerve plexus that help control limb movement. Cannot these be considered part of the brain?
how can our brain be real if our eyes aren't real
Consciousness is whole body ...
I am so blanking on it and can't spell names anyhow, but just the title of this made me think of an Anime where the girl who thought she was read was fake the whole time as the number on her eye show she was a clone
Huh.... So I might actually be feeling tired in my eyes being real tired not just eye tired....
as ophthalmologist... we have a saying.........the brain is just an extension of the eye. lol
Take a shot each time he says "brain"
Ah, but what about the gut-brain?
We are our brain and nothing more. Components such as eyes are like extensions that function when plugged in. We are seated at the top of a bipedal organic robot and command it through organic cables, wires, and fluids. We're directly tethered to the health of this organic robot and even something like strange gut bacteria can directly influence our core processing unit (brain). The body is like software and it can damage and stress brain hardware.
Is a webcam a part of a computer? Well yes, when plugged in, but they aren't a core part of the computer. The camera adds additional hardware the computer lacks but most of the processing and heavy-lifting is still done by the computer its plugged in to.
Oh, and we don't have souls. We aren't even our bodies. We maintain rights to our bodies only because of how they impact our brains. If we were separated from our bodies then they would no longer be our body. It's just an organic case our brain needed to survive and thrive because squishy brain alone on ground can't do anything. We need to pilot organic robot bodies to be useful. Just wish mine would fit in a younger model (giggity).
What about the body as a whole?
What about the clump of neurons in your stomach? It's the size of a cat's brain!
Yes
Not very scientific, but I'd argue anything on the brain side of the Blood-Brain Barrier is brain. So, central nervous system I guess. I have Multiple Sclerosis, and I've had lesions in my brain and spinal cord, and the medication I take prevents certain immune cells from crossing into my CNS. I don't think MS lesions happen, in say, the fingers. Considering the neurological symptoms from just having lesions in the CNS, I'd argue at least from a layman's standpoint, the CNS is probably a good definition of the extent of the human brain. At least it seems pretty straightforward to me to think "If I can get MS lesions there it's brain, and if not, it's not brain".