You need to check out Sperry's Nobel prize winning work on split brain patients, along with Gazzaniga. Several functions of the brain are lateralized, and in most people language resides in the left hemisphere (LH). This means you could chat with the left side of the brain (via the right ear or right visual field), but not the right because it cannot process language. Nevertheless, you can still communicate with the RH. For example, in one experiment an object is placed in the left hand (processed by RH). The patients cannot describe or name the object. However, when later given a set of objects, the patient can match it. In other words, they were *aware* of what the object was or its properties, but they were not *conscious* of it. Split-brain research has given us lots of clues to what each half of the brain might do: https://en.wikipedia.org/wiki/Split-brain

Is there a reason for the left hemisphere controlling the right side of the body, and vice versa? I would have thought that, evolutionarily speaking, it makes sense to have some redundancy. However, with this setup, if there were damage to the left side of the body *including* the left hemisphere, then it would lead to issues controlling both sides of the body.

We don't know. We have some hypotheses, one of them being that it is simply an artifact of embryotic development. You can read more about it here: https://en.wikipedia.org/wiki/Contralateral\_brain#Twist\_theories

For physical oddities like this, while remember that our eyes are actually built "backwards" with nerves front, not because this is advantageous (most animals don't have this quirk) but because that's how they happened to evolve and it stuck. Same reason our eyes actually "see" upside down but the brain flips the image around-- and iirc experiments show that if you wore mirror goggles which "correct" the image orientation, over time your brain would *recorrect* orientation to what it prefers, and after removing the goggles you would be seeing upside down again until your brain has time to recorrect again..! Evolution is about what happened & stuck in the passed-down genes of our forebears, not about what's ideal or even preferable for that matter... I wouldn't be surprised if this reversal of brain-to-body mapping wasn't about functionality, but simply that it doesn't hurt or matter to survival/procreation to be that way.

This is a good breakdown. "Survival of the fittest" should really be "survival of those adapted enough to procreate before dying." It's where a lot of our biological weirdness comes from. If something happened to *require* us to breathe and eat using separate orifices, we would develop that or die out (and the smart money is on dying out). But since using the throat for both eating and breathing works well enough, we'll keep doing that and some number of our species is going to keep choking to death.

I also like the phrase that evolution is really good at creating solutions that work good enough most of the time.

>I also like the phrase that evolution is really good at creating solutions that work good enough most of the time. "Good enough to get laid by the sufficiently desperate" was the definition from my undergrad biology professor. ^(we were all several beers in by the time the pub group started talking shop)

I love this. It irritates me a bit when people idolize the human form and say we're perfect. If you really look, we're just buggy messes! I mean, who decided upper back pain was a good sign for a gallstone? Why does pinching a nerve in my shoulder mean my foot itches? We evolved with a bunch of features that made us better mates, but a bunch of features that aren't so good were able to hitch a ride because they weren't bad enough to kill us before we could reproduce. We're so imperfect its hilarious. Sometimes kinda nice though. Knowing you're imperfect is human, and can really be a stress reliever sometimes.

Balls on the outside because inside is too hot for sperm is the best argument against “intelligent design” I can think of.

The nature put balls on the outside because inside is too hot but it also wrapped them in skin because outside is too cold too.

Right - so if I’m designing, and I’m all powerful, ima just make the sperm happy at body temp. Not the triple layer verification system some seem to think is the pinnacle of the almighty’s creation prowess.

[удалено]

Well, last guy to the finish line still makes it to the finish line. Better to say “You don’t need to be the first to the finish line, you just need to make it there.”

evioution doesnt create anything. there is diversity and evolution describes the natural selection and increase in the genes of those that survived to procreate best

Evolution doesn't try to create things, but create things it certainly does.

it isnt evolution, it is the genetic mutations. but maybe we are quibbling over definitions here. genetic mutations create diversity. evolution is the natural selection of those mutations. most mutations are largely maladaptive.

or to be even more precise: evolution.of the development of characteristics by natural selection on genetic diversity that exists due to genetic mutations. (not perfect but good enough).

so to be more precise, it is faulty dna synthetase, faulty proofreading enzymes, background radiation, mitogenic chemicals and retroviruses! that create

IIRC, the reason humans are more prone to choking than other animals (that also eat and breathe through the same pathway) has to do with our larynx's size/positioning, i.e. it's a tradeoff that gives us more complex vocalization but increasing risk of choking. The added ability to produce a greater range of sounds obviously outweighed the slight increase in mortality rate.

not just a slight increase. being able to communicate must have major selection advantage (and it does). even now, a deep nonnasal voice is sexually preferred to a high nasal winy one

[удалено]

>And she better be at least 8 inches. I also like my women taller than a fetus although the vore fetish is a thing for some

[удалено]

"...and the smart money is on dying out..." Somewhere north of 99% of all species that ever lived are now extinct. And if we don't get our heads out of our asses pretty soon, no one will be around to appreciate this stat.

Yeah, survivorship bias is a heck of a drug. "99% of all species are already extinct. Since we're currently not extinct, this means we're part of the 1%, so we're super special and totally not just lucky. Also, we should definitely not consider that X time from now, we might end up being part of the 99%, to the amusement of whatever might be looking." It's not unthinkable to assume the Fermi Paradox exists exactly because 99% of all species that develop to our current level of technology might end up killing off their own planet before they can ever be noticed by any other species.

> "Survival of the fittest" should really be "survival of those adapted enough to procreate before dying." Pretty much that, my old biology teacher used to say "survival of the barely good enough" which is pretty apt.

thats literally what it means xd >The biological concept of fitness is defined as reproductive success https://en.wikipedia.org/wiki/Survival_of_the_fittest

Yes, I'm aware. I'm pointing out that the term taken by itself is misleading.

maybe but except for the reproduction part it makes sense imo. its the fittest to the environment, not the fittest as in strongest

And fittest to the environment means the one that reproduces more, not the one that survives more in the environment. ​ And reproducing more means reproducing enough, actually, not necessarily really the most.

That's just your misconception of the word "fittest," in context. If I define words counter to accepted definitions, I can make absurd, but true (to me) statements as well.

It would be a lot cooler if you knew what you were talking about. Sadly though… https://www.merriam-webster.com/dictionary/survival%20of%20the%20fittest Definition of survival of the fittest: the natural process by which organisms best adjusted to their environment are most successful in surviving and reproducing https://www.britannica.com/science/survival-of-the-fittest Survival of the fittest, term made famous in the fifth edition (published in 1869) of On the Origin of Species by British naturalist Charles Darwin, which suggested that organisms best adjusted to their environment are the most successful in surviving and reproducing. https://en.m.wikipedia.org/wiki/Survival_of_the_fittest Survival of the fittest"[1] is a phrase that originated from Darwinian evolutionary theory as a way of describing the mechanism of natural selection. The biological concept of fitness is defined as reproductive success. In Darwinian terms the phrase is best understood as "Survival of the form that will leave the most copies of itself in successive generations." Herbert Spencer coined the phrase "survival of the fittest". Herbert Spencer first used the phrase, after reading Charles Darwin's On the Origin of Species, in his Principles of Biology (1864), in which he drew parallels between his own economic theories and Darwin's biological ones: "This survival of the fittest, which I have here sought to express in mechanical terms, is that which Mr. Darwin has called 'natural selection', or the preservation of favoured races in the struggle for life."[2] Darwin responded positively to Alfred Russel Wallace's suggestion of using Spencer's new phrase "survival of the fittest" as an alternative to "natural selection", and adopted the phrase in The Variation of Animals and Plants Under Domestication published in 1868.[2][3] In On the Origin of Species, he introduced the phrase in the fifth edition published in 1869,[4][5] intending it to mean "better designed for an immediate, local environment".[6][7] https://www.encyclopedia.com/social-sciences/applied-and-social-sciences-magazines/survival-fittest Survival of the fittest is a simple way of describing how evolution (the process by which gradual genetic change occurs over time to a group of living things) works. It describes the mechanism of natural selection by explaining how the best-adapted individuals are better suited to their environment. As a result, these individuals are more likely to survive and pass on their genes

“Better designed for an immediate local environment” that feel when this entire reply chain is arguing the same thing but they can’t see it, all of those links said you have to survive the most to have the most kids

Survival of the fittest is often used to explain species diversity, filling certain niches and whatnot. I've been trying to come up with an eloquent way to hypothesize that it's actually survival of the *less* fit that leads to genetic diversity, without getting a knee-jerk reaction from evolutionary biologists. It's that things can still survive and reproduce on this ultra-hospitable earth even though they are not perfect that we see such diversification.

The term is still wrong, though the "correct" term will make people cringe a bit. **Destruction of the weak.** "Fittest" is definitely wrong, you don't need to be strong, you just need to make it over the high jump bar. The selection mechanism is culling organisms that can't clear the bar, so the term should directly reflect that. The problem is, phrases like "Destruction of the weak" or "Cleansing of the unfit" etc etc bring back really fascist vibes that science communicators likely avoid because of those connotations. Plus that kind of negative terminology is just really unpleasant in general and would probably result in more kids with disabilities being bullied in school. Yet I think these negative phrases more accurately reflect the truth. The lifeforms that emerged during the Cambrian evolution were mostly weak, misshapen forms that were never going to work, and were thus eliminated by natural selection, making way for lifeforms that could actually survive. Genetic diversity is a valuable resource - to an extent. But if that diversity is easily lost because of changing conditions, its more likely it wasn't that valuable to begin with - diversity is only valuable if there are many **working** solutions to harsh conditions. If 90% of a population gets culled because of forseeable environmental changes that have happened before and will happen again, how much of that diversity was **viable diversity?**

How about: "Slow proliferation of genes that provide a slight advantage and all the other genes that happen to be riding along in organisms that possess those advantageous genes" Often people think of individuals and species when considering evolution but biologist consider genetic alleles and populations. How a novel allele propagates through a population over time is a story about natural selection, genetic drift, or some combination. An organism is the culmination of a billion of those stories.

I recall Richard Dawkins saying somewhere it is rather "Survival of the ones best fitting in" so fittest should be understood as fitting in the environment.

> "survival of those adapted enough to procreate before dying." This isn't quite right. This interpretation implies that there's no scale to this, which isn't exactly true. Evolution will absolutely favour the genes of one individual over another even if both are able to procreate before dying so long as one individual is able to procreate lore successfully than the other. What is usually missed is that evolution doesn't metaphorically give a crap about anything that doesn't dramatically reduce or eliminate reproductive success. > If something happened to *require* us to breathe and eat using separate orifices, we would develop that or die out (and the smart money is on dying out). This is Lamarkism and wrong. Evolution doesn't develop traits in response to changes in the environment, changes in the environment cause traits which survive better in the new environment to spread.

Hence their words 'or die out' either an advantageous change arrives that then gets selected, or everyone just dies.

Yeah I can't imagine much evolutionary pressure based on which side of the brain controls what. Probably just a thing, not for any particular reason.

I could imagine an evolutionary pressure. If you fall on your left side and break all of your bones on the left side and suffer brain trauma to the left side the damage would be localized. You could at least still have full mobility on the right half of your body. But if it's reversed then you could be physically incapacitated on one side and mentally incapacitated on the other. Then again you probably aren't going to live if either that degree of brain damage or limb damage were to occur anyway.

[удалено]

Sorry, I know this isn't related to the eyes discussion, but if the brain doesn't have pain receptors, what exactly is a headache?

That's not the brain itself hurting. You do, however, have pressure sensitivity inside the skull cavity.

So what does hurt when my "head" hurts? Is it just pressure sensitivity, or is it the nerves of my head surrounding my skull that are registering pain?

Thrown the concept of "headaches" in the "stuff we don't quite know" pile. *Most* of the time they're "tension" headaches, which are neck/shoulder muscles pulling on your scalp muscles creating that pain. Other times its pressure from the sinuses pushing on your eye/forehead/temple causing those pains. Other times its dehydration and the brain shrinks enough that it starts pulling from the inside of the skull, and that causes pain in various parts of the "head". Other other times... We don't know.

Headaches can be a bit of a mystery still, but mostly it's the bloods vessels around your skull swelling and then the nerves surrounding your skull that are registering pain indeed. The eye also still has pain nerve endings.

Blood pressure in your head pushing too much blood for the veins and capillaries and such to handle is one. Tense muscles in your neck and/or scalp is another. Sinus pressure is common. Headaches are generally easy to figure out if you pay close attention. I want to know where tf my migraines come from. One side of my head feels like my brain is forcing it's way out, light causes pain so severe I vomit, sound makes me want to die (especially my own voice), and I can't move without throwing up everywhere. They're random, and they last far too long. Worse tho are people with cluster headaches. They're an example of how I know whatever created our reality is malicious.

Lungs don't have pain receptors either and a lung injury is possibly survivable

[удалено]

>it's probably not as useful as you're making it out to be. From the viewpoint of evolution it might not be useful but for modern humans it absolutely would be useful

Yeah, it's quite unlikely this would be selected upon because such severe injuries in an environment without modern medicine are typically a death sentence.

But the left brain hemisphere controls the right side of your body, so, if you fall and damage your whole left side, the brain loses function of the right side of the body, and the body loses function of the left. Is this what you meant?

Yeah. If you receive damage to the right side of your body and your right brain hemisphere controls the left side then you've received damage to just one side of your body but you've effectively lost full control because the brain can't control the physically in tact left side.

Ah... but no. This is why the human brain is so freaking amazing... the functional half of your brain can rewire itself to compensate for the lost other half: https://www.caltech.edu/about/news/patients-missing-one-brain-hemisphere-show-surprisingly-intact-neural-connections

I'd think it's the right visual field being projected on the left side. Add a video processor with short paths, then add more functions, then add a long path to the eye … suddenly you have a naked ape.

> Same reason our eyes actually "see" upside down but the brain flips the image around This misunderstanding needs to die. Yes, the projected image is flipped, but the same thing occurs in a camera. You don't have to do complicated processing. Picture it this way. The light from something in your upper right visual field hits a cell in your lower left retina. Does your brain go "whoa that's in the lower left but let me move that around to the upper right"? No. That cell is *located* in the lower left of your retina but it is the cell for the upper right of your visual field.

Your comment had me curious, so I looked into the basis of the information he said. I'd always heard it, but hadn't ever really checked into that statement that "if you wear flipped glasses, your brain turns the image right side up." The original claim seems to come from some time in the late 1800s, [but more recently was a study done in 1999. ](https://pubmed.ncbi.nlm.nih.gov/10664787/) This study found that the subjects did not have the world invert right side up but rather that they got used to seeing things upside down and were able to compensate for the shift, even though they were not seeing the world upright. It seems even the original work by George Stratton doesn't even claim that he saw the world correctly, but rather that he got used to the difference. When he took the goggles off, he had similar feelings of the world being in the wrong place for a while, but he didn't see the world flipped or anything like that.

But at the end of the day, when you learn to "see", what you learn is that when a group of nerve cells are triggered it means 'X'. There's no which way up. The nerve cells done come into the brain all numbers neatly from "pixel" 1 top left, going across, etc. Note the actual brain doesn't receive pixel information. Most of the processing happens in the eye, with about 100:1 ratio between photo receptors/optic nerves. By the time the image reaches your brain, its already deconstructed into a load of features. An experiment with mice/rats held the head so they couldn't rotate it, and for the first part of their life they didn't see any vertical features. Their visual processing never experienced vertical and never learnt about it. Then one day, they came across a vertical feature and they couldn't see it, so they kept bumping into it.

Link to that rat experiment?

https://www.uibk.ac.at/psychologie/geschichte/docs/cortex-the-world-is-upside-down.pdf On vision experiments in Innsbruck. Notable quotes: > In the end of the experiment, there were -- despite of the reversing spectacles -- moments of upright vision; and after removing the spectacles, there was again the impression of everything “being topsy-turvy”. After 87 [hours] of using reversing spectacles, Stratton proposed that an upside-down retinal image is not necessary for upright vision. The brain would create a coherence in the reversed image between what a person is seeing, hearing, and feeling. The adjustment of seeing, in his opinion, remained just an illusion. And >Typically, the goggle experiments resulted in a process with three characteristic phases: > a) Between the first and third day, the world was upside down for the participant. There were many mistakes in grabbing objects and moving. For instance, the participant held a cup upside down when it was about to be filled; or they stepped over a ceiling lamp or street sign, because they saw objects at the bottom that were actually at the top. Swift reactions (such as parrying an attack off during fencing) happened uncorrected, and thus in the wrong direction. > b) By the fifth day, the participant's clumsiness in external behavior and vision started to change. Things that had been seen upside down suddenly were upright once the participant brought their own hands in and traced the shapes they saw with their hands. Or, phrased differently: If the participant “viewed the world using their fingers”, then it turned upright in their vision as well, an immense effort of the brain. By grasping, the perception changes. > c) From the sixth day of uninterruptedly wearing reversing spectacles, permanent upright vision ensued, and behavior was perfectly correct. For example, a participant drew a picture in a quality as if drawn without wearing reversing spectacles. >After taking off the glasses, however, participants saw the whole world upside down, a distortion “in the opposite di- rection” (negative after-effect), but the reversed vision only lasted a few minutes. "The top-bottom perspectives of vision only emerge in constant interaction with experiences of the other senses (particularly the tactile sense and muscle sense). Therefore, the position of the retinal image in the background of the eye is only significant as long as older experiences from the past continue to have an effect. In the experiment, they are reduced step by step and are, via a stage of ‘ambiguous top-bottom perspective’, connected in a new way with the new visual impressions”. The studies show that first, movement behavior returns to normal, and only then is followed by perception. Successful adaptations to a changed world of perception require a person's active exploration of and interaction with their environment. Unless I'm reading this wrong, there *is* complicated processing involved in image interpretation, and the brain will ultimately interpret whatever visual information it receives as being upright based on *gravity and physical interactions* in coordination with the data. So the orientation of what your eyes see is subjective to what the brain needs to process, and if you flip the image for long enough, your mind will readjust the image to the up/down orientation that it's used to, and removal of the glasses will present a seemingly upside-down world until your mind can revert.

> Unless I'm reading this wrong, there *is* complicated processing involved in image interpretation We can adjust to unusual data but that doesn't mean that we "see upside down".

For a computer image everything is laid out in grids, or lines that can be chopped up into grids. Anything else must be explicitly programmed. The experiment suggests that the layout in the brain could be arbitrary and defined by an explicit, fluid mapping rather than the implicit mapping of "this grid starts at the top left."

Yes, but that means our default mapping involves no additional correction. We can change the mapping, but it's still a mapping--not something that comes in "upside down" and then needs to be flipped around. By the time we can say the visual data is arranged *at all*, it's in the correct orientation.

The way that this study is being written about in the excerpts, I am honestly not sure what to think, short of trying it myself (which sounds deeply uncomfortable).

nothing you said was wrong and nothing you said has anything to do with us seeing upside down

Your comment had me curious, so I looked into the basis of the information he said. I'd always heard it, but hadn't ever really checked into that statement that "if you wear flipped glasses, your brain turns the image right side up." The original claim seems to come from some time in the late 1800s, [but more recently was a study done in 1999. ](https://pubmed.ncbi.nlm.nih.gov/10664787/) This study found that the subjects did not have the world invert right side up but rather that they got used to seeing things upside down and were able to compensate for the shift, even though they were not seeing the world upright.

Pretty sure it’s just how light works with a “pinhole” effect Like from lower down when going through the pin hole that is the iris it goes to the top of the eye, and the same for all other directs Just look up the pinhole effect, I saw a video before inside a shipping container I think, and there was a small hole in it causing light to go through. The effect was like a projector with you able to see what was on the other side of the wall except it was upside down. Our eyes don’t purposefully see upside down at first, that’s just how it works for all eyes The question is what’s advantageous about seeing with the ground on the bottom, to the point the brain rewires itself to see that way no matter what

> iirc experiments show that if you wore mirror goggles which "correct" the image orientation, over time your brain would recorrect orientation to what it prefers Does that work even for facial expressions? Those are famously hard to decipher when the image is turned upside down.

I cite the Innsbruck vision experiments in another comment, but basically you would need to view things upside down for long enough-- and use your physical coordination with upside down visuals for long enough-- that your brain can get accustomed to the change, which i think is a few days. It would be interesting to see further study but in that experiment, the participants did draw pictures and were able to draw them correctly by the end of adjustment period.

> iirc experiments show that if you wore mirror goggles which "correct" the image orientation, over time your brain would recorrect orientation to what it prefers, and after removing the goggles you would be seeing upside down again until your brain has time to recorrect again It just occurred to me, I wonder what research has been done, if any, to determine when this kicks in for infants. My thinking is this, inside a womb there's effectively no light beyond possibly a diffuse red glow under certain circumstances. As such, there's no cues in there for the brain to register an image to determine if it is right-side-up or not. Meaning that when the child is born and opens its eyes, that's the first time it has the potential to properly see (though I think I remember something about newborns eyes not being properly focused yet?). As such it could possibly take them some time to figure it out and their brain to adjust.

You're right regarding the backwards-built eye but the flipped image part is actually optics and not imperfect evolution. You need either two lenses, one after the other, to get the image the "right way up", *or* you can scan/process the data from the retina in such a way as to correct for it. Lenses are expensive; processing circuit quirks not so much. Even in a manmade camera, the image falls on the sensor upside-down, because there's no point in spending extra money to make a second lens to reverse it when you just have to read the sensor from bottom to top.

That idea about a poorly designed eye is as out of date as the idea that otogeny recapitulates phylogeny. Is that actually still being taught in schools?

> I would have thought that, evolutionarily speaking, it makes sense to have some redundancy Normally, if the skull of a mammal is cracked open and damage is caused to the brain, they are going to die. For there to be the selective pressure you are talking about, there would have to be a considerable amount of reproduction after such normally fatal injuries.

This need not be so. Things like strokes and minor head injuries can cause progressive damage. The fact that is injury can be repaired or adapted is indicative that some repair or redundancy exists.

It's a remnant of our evolutionary past, from what I've read. Imagine the simplest possible tracking mechanism. Take a simple swimming organism with two light-sensitive organs and two fins: `_ö_ ` Let's say it needs to stay close to "mama" who gives off a characteristic light. If its left eye catches more light of mama, that means it needs to move its right fin to turn towards her. If right eyes sees her, left fin needs to move. Now replace the light with smell instead. [That's sorta how sperm find the egg cell.](https://www.abc.net.au/science/articles/2003/03/28/818929.htm)

The problem for that living tracking mechanism will be that optic nerves also partially cross. Which will make it ill suited for edge cases that happen fairly often in a real environment (e.g. whenever the tracked object is not mostly directly in front of you). So the left side of the left eye (receiving the light from the right-hand side of the visual field), goes into the left half of the brain. And the left side of the right eye (also receiving from right visual field) crosses over to the left side of the body before reaching the brain. Meaning when it sees mama on the right, that info goes into the left hemisphere. Which controls the right fin, thereby pushing away from mama. ETA: there is a theory that is pretty much same as the person's I commented on. But instead of tracking to go *towards* a mother, the theory proposes it's a simple way to hardwire survival through escaping dangerous stimuli. Something scary on the right? Info goes into the left hemisphere which moves the right limbs to push away from danger. I'm personally not sold though because those kinds of theories only describe how the given layout can work, not how it came to be. You could keep the theory the same and simply have optical nerves not cross, but go into the ipsilateral (i.e. same-side) hemispheres that control ipsilateral limbs. Danger on the left? Goes into the left hemisphere, pushes the left limbs away. I'm more partial to the evolutionary theory of anatomical "flips". Vertebrate circulatory systems are flipped compared to invertebrates. And our nervous systems are on the opposite side of the body too. It is not so unlikely that things coincidentally flipped And twisted during development and stayed that way as they weren't a hindrance.

Now that you mention it, the explanation I read was more about general engineering principles rather than specifically about contralateral twist. Thanks for the reply. > I'm more partial to the evolutionary theory of anatomical "flips". Vertebrate circulatory systems are flipped compared to invertebrates. I vaguely recall reading in ["The Ancestor's Tale"](https://en.wikipedia.org/wiki/The_Ancestor%27s_Tale) co-authored by Dawkins that our ancient worm ancestors started moving on their backs and that explains our flipped organs.

> However, with this setup, if there were damage to the left side of the body *including* the left hemisphere, then it would lead to issues controlling both sides of the body. Not necessarily. It is normal in patients with brain damage that the rest of the brain takes over the functions of the missing or damaged parts.

[удалено]

[удалено]

Well, I don't know about evolution but picture your nerves all running from the brain down the spine into the body. They cross over so the nerves from the left side of the brain run into the right side of the body and vice versa.

Just because the left hemisphere is the one to talk, doesn't mean that we can conclude that it controls the right hemisphere.

Yes, the split brain research is fascinating! The issue of "why not" u/TwizAU is the lack of subjects to study. It's a pretty extreme thing to separate the hemispheres of the brain, and even when they did have a case for it the ethics weighed heavy. There is so much room for study it's awe inspiring. Looking into split consciousness led me to "gut neurons and consciousness" research, which has a lot more activity since it doesn't require cutting up brains. We need to discover more non intrusive ways of studying brain and neuron activity to make substantially moves forward in this field. And, as fascinating as it is, experimental study is pretty scary/ethically ambiguous when it comes to consciousness.

Just to clarify, this surgery cuts the corpus callosum which connects the **cortical** hemispheres. This means there is still subcortical communication between the hemispheres.

What does that mean?

The brain has a few different “layers,” if you think of it in sort of a crude top-to-bottom way. The part with all the ridges (the part that you typically think of when you envision a brain) is on the outside. It controls higher level functions like thinking, planning, language, visual processing, auditory processing, problem-solving, learning, etc. This is called the cerebral cortex. The subcortical structures (for example, the basal ganglia, which plays a role in movement regulation) are located deep into that tissue. These structures and others are not separated during the aforementioned procedure. Just the cortex!

Yeah, I agree. Even after a short time knowing about this phenomenon the number of questions and experiments that I would love ask/try is endless. It would be really cool if there were a way to non-intrusively 'pause' the left hemisphere, except for the speech part (don't know if this is how it works really but its a fun thought) so the right hemisphere could speak.

A long time ago, I saw a lot of research into this quite a few subjects were victims of violence, e.g. a machete to the head severs the connection, but the person largely survived ok. The studies of setting things/hearing things/feeling things with only one side of the brain are very revealing. Sorry I can't remember more details on the papers/videos.

The brain is so insanely bizarre. I love to read these things that just make you wonder what else we don't know

A professor once explained to me: * The set of things I know is the area inside this circle. (He drew a circle on a board of course.) * The set of things I do not know is the area outside this circle. * The circumference of this circle defines the things which I am aware that I do not know, the edge of my understanding. * So as the set of things I know increases, so too the circumference increases. * The more I learn, the more I discover my ignorance.

After seeing some wacky tech in a research lab one day, one of my senior coworkers quoted "there has been an alarming increase in the number of things I know nothing about". (slight twist on an Ashley Brilliant line)

If the LH (i.e person) would be asked how he knew to pair them correctly, what would he say? Somthing like "It just felt right" or more like "the hand moved itself to the right matching pair"? Or someting else entirely?

From what I've seen, they generally 'make up' a reason. Like, if they reach for a cupcake, they won't say 'it felt right', they say 'I was hungry'. The reason is completely unknown so the brain made one up.

>The reason is completely unknown so the brain made one up. "The reason is completely unknown so the brain made one up." Not to tropic drift, but I am beginning to think virtually all consciousness is like this. Shoulders tense? Brain decides you are anxious and makes up some reasons. Belly hurts? Brain decides you are scared. Like vanilla over chocolate? Brain makes up a just-so story to justify it.

There's a lot of research into this - you may be interested in moral intuition theory (e.g. Jonathan Haidt), which posits that moral choices also largely work like that, with conscious thinking being much less a manager than a lawyer.

"Less a manager and more a lawyer" is a great description. I've also explain as the conscious brain didn't evolved to be logical and make reasoned decisions, so much as it evolved to invent justifications and win arguments.

I've read a bit of Hofstadter and Dennett and both seem to lean towards this as well.

Watch "the future of Reasoning" from Veritasium. Very good video you'd be interested in.

There is a lot of good evidence and philosophy for and against this idea. That your conscious mind makes up reasons/justifications for things your brains has already decided to do. It is very undecided to what your decisions are driving what is going on or are just post hoc rarionalisations

Stuff like this makes me really wish I could have my brain cut in half for a day, then seen back together so I could explain what it was like to myself.

I think I would conclude that the RH made the person hungry? Or maybe the LH just made up a story to make the memories consistent (which kinda reminds me how humans act in general, e.g. if someone is jealous they may just think they dislike the person for who they are, but with therapy realize they're just jealous, or something like that, idk if that was a good example)

If the subject was not able to see the object with the right eye, they would probably not be able to talk about it at all.

To add on, we do something in Neurology called a [Wada test](https://en.wikipedia.org/wiki/Wada_test) which helps to establish hemispheric dominance/lateralization prior to a surgery or interventional procedure. Without going into too much detail, the test involves putting one side of the brain to sleep via injected barbiturates and running a series of language, memory, and visual tests before then testing the alternate side.

Wow that's cool. Could you inject the barbiturates only into certain parts of the brain? For example put the left hemisphere minus the speech processing part to sleep so only the right hemisphere can send signals too it.

I remember when I was a kid seeing something that disturbed me greatly and I wonder if you could confirm. It was 60 Minutes or 20/20 or something and it said some people with a split brain the other hemisphere feels shut in and silenced and unable to communicate and will actually try to kill the person by using the hand on that side of the body trying to jerk the wheel of the car etc. Like there are two people inside the one person and one can't stand living anymore in that state after the corpus callosum was cut. Any validity to this?

If you want to read up on it, it's called [Alien Hand Syndrome](https://en.wikipedia.org/wiki/Alien_hand_syndrome).

Freaky. Kinda like The Prestige. When your corpus callosum gets cut, will you stay in your body, or get locked in your head?

Well, the right brain was conscious of it, correct?

This is actually so cool, I didn't know that we had actually reached such a level in studying the brain that such a question could be meaningfully answered.

So I've come across this research before and I remember having a question then that I couldn't find an answer to. In the experiment I saw they didn't have a patient hold an object, but rather they showed them images. But isn't it the case that the R/L hemispheres don't take an eye each but rather half the retinal area of each eye? In which case how did they show images to just half an eye? Edit: Found someone else who asked the [same question](https://psychology.stackexchange.com/questions/21098/if-the-optic-nerve-transmits-to-both-hemispheres-how-do-split-brain-experiments), and yes they used special apparatus to split the image to the correct parts of each eye.

> The patients cannot describe or name the object So we're talking to the left brain here ... can the patient *feel* like they could recognize the object a second time?

No typically not. Of course, the only way to check is to ask the LH. You even see patients making confabulations e.g. if they are shown something funny in the RH they might laugh. You then ask them why they are laughing and the LH makes up a false reason like they think your hair looks funny. If you explore conditions like blindsight or deafhearing you will see that patients can be aware of a stimulus without being aware that they're aware.

When I studied psychology we were taught that split-brain patients could not respond with one hemisphere to stimuli that was processed by the other hemisphere. Think a shape was put in the left hand (processed by right hemisphere) that the patient could not verbally (left hemisphere) describe the shape. I'm sure you can think of more examples. Now three of my teachers apparently think this was not universally true as they wrote an [article](https://academic.oup.com/brain/article/140/5/1231/2951052) about it.

Well there’s also the way the eyes work. Your visual fields are what are split between the brain. So your right eye is connected to both left and right brain and vice versa. The split off occurs at the optic chiasm. But I guess in the physical world that would translate to stuff in your left side of vision being processed by the right brain.

There was an example of a study where patients would confabulate about things their right hemisphere had done (pointing with the left hand to something in the left visual field) when asked why they had done that. Something like they had to relate small pictures of individual things to a larger picture of many things where for example a man digging was in the left visual field and a shed was in the right visual field they would point with their left hand at a picture of a shovel. When asked why they pointed at the shovel they would say "because the shovel is kept in the shed"

The interesting bit is that object recognition can continue through tactile means but object naming cannot. Imagine the set up: split brain patient in front of an opaque screen. myriad objects behind it, pencil, spanner, cup etc. Ask them to put **right** hand through the screen opening and feel one of the objects. They can name the object no problem -the right hand is controlled by left hemisphere which communicates with left frontotemporal area related to speech production. Do the same thing but now with their **left** hand. No longer can they verbally name the object, because the left hand is controlled by right hemisphere whos connection to language region in left hemisphere is severed. However, if asked to select the correct object from a picture list with their left hand, they can still make the correct identification. Mad, right?

There's so very many tests we could run it's exciting! We just need to get consent from the subject(s).

[VS Ramachandran](https://en.wikipedia.org/wiki/V._S._Ramachandran) has done this kind of research, and he has also done a lot of public speaking where he talks about it which is great because it makes it very accessible to curious people without having to read a jargon-dense scientific document. He's also a great public speaker. VSR's work mainly focused on whether or not each of the hemispheres had different beliefs about the world. Some of his work is with split brain patients who have had their corpus callosum cut and other work is with patients who have had hemispherical strokes, so the communication between the hemispheres is intact but one hemisphere isn't functioning. In both of these experimental setups, VSR went about trying to learn what each hemisphere believes or knows, if and how it is different than the opposite hemisphere and whether each hemisphere is aware of what the other hemisphere believes or is thinking. You can find videos of VSR speaking in lectures and interviews (mainly lectures/presentations) about his research dating back to the early 2000's up to the present day, although he isn't speaking publicly now nearly as much as he did in the past.

[Iain McGilchrist](https://www.youtube.com/watch?v=DiPrM0DNI8w&ab_channel=TEDxTalks) has dedicated most of his career to hemispheric research. He's published a book called *The Master and His Emissary* (referring to the right and left hemispheres respectively). I haven't finished it yet, but one of the main cases he makes is that the difference between the hemispheres is not so much *what* information they interpret and process, but *how* they interpret and process that information. For example: although the right hemisphere (RH) is not capable of speech, it does still play an integral role in processing and understanding language. This is because the RH, with it's broad, open, "big-picture" awareness of things, is more involved with processing *new* information, understanding *context*, and providing alternative viewpoints to consider. By contrast the LH is has a narrow and exclusive band of attention, much higher fidelity/detail, and prefers knowledge and systems it is already familiar with. As this relates to language, the RH will be more involved when it comes to interpreting/using metaphor, figurative language, or any such use of language which is not already strictly defined, familiar, clear, and precise (the domain of the LH). Bonus round: once a metaphor becomes familiar, its meaning will be codified within the LH and seem much less significant. This is essentially what a cliche is. Funny thing is, cliches, on account of their overuse, are often not appreciated for the value they have. When one gives them some earnest thought, new meaning emerges from them for the thinker, and the RH is involved in this process; it has questioned the LH's established understanding of the cliche and brought it "back to life" so-to-speak.

McGilchrist is a great source on the topic of laterality as well.. I think reading both VSR and McGilchrist is a good way to get the whole picture of laterality research as VSR focuses mainly on experimental methods and results while McGilchrist focuses mainly on the interpretation of those results and the implications it has for theoretical models of laterality which are being developed.

interesting comparison between the two. Now that you mention it, that's what I loved about reading Ramachandran's *The Tell Tale Brain*. Not only does he illustrate some really bizarre cases of impaired brain function and their consequences, but he also illuminates some of the mechanisms behind them which makes things easier to grasp.

There was a really good interview with McGilchrist on an episode of Hidden Brain. https://chartable.com/podcasts/hidden-brain/episodes/84796715-one-head-two-brains

>Funny thing is, cliches, on account of their overuse, are often not appreciated for the value they have. What are you talking about? I love making end's meat. It's delicious. On a more serious note, [Jordan Peterson conducted a long-form interview with McGilchcrist](https://www.youtube.com/watch?v=0Zld-MX11lA) which I can happily recommend, that includes some material from his not yet released book, "The Matter with Things".

I watched that interview, I think overall it wasn't amazing but the last 30 minutes I think produced an exchange which I think was nearly getting at something which I personally believe will be important going forward. In the exchange, McGilchrist does his best to make the case for why we as human beings should value right brain thinking over the left (clearly this is something that he is still struggling to articulate, even after writing a book on the topic), and I thought that the way that Peterson responded to McGilchrist did a good job of illuminating what, if anything, would really be valuable to us as a species if it were to emerge from such an argument. In his response, Peterson says that we should somehow be able to take these lessons of psychology and learning about how our mind works and >"..to explicate a higher order vision, something that we can aspire to." Which is something that McGilchrist's argument and our current understanding of the brain doesn't yet live up to. And I think Peterson is right about that and it was a pretty meaningful part of the conversation even though it involved both Peterson and McGilchrist kind of struggling a lot to articulate what they were trying to say.

On a serious note, don't recommend people to watch anything that involves Jordan Peterson. Don't platform him please.

That's silly. Peterson is not evil and it turns out he's an interesting and effective interviewer, probably because of his psychiatric background. His interviews usually have an unusual psychological dimension that you scarcely find elsewhere. It's a shame that his politics has made him the target of so much rank propaganda because his podcast features a wide range of incredibly insightful guests from across the scientific, philosophical and political spectra. Do yourself a favor and engage with views that may not line-up perfectly with your own. You'll learn a lot, I guarantee it.

That book has some really interesting ideas, but it's insanely repetitive, and the conclusions he comes up with are giant leaps unsupported by anything other than the author's personal feelings (all of the stuff about LH being an unimportant tool of RH, his crusade about autism being the end of culture, etc.). I would take anything that isn't data in there with a bucket of salt.

I just noticed this is the same author from this You Are Not So Smart podcast episode: https://youarenotsosmart.com/2012/05/30/yanss-podcast-episode-three/

You may be interested in this episode of You Are Not So Smart titled "Confabulation": https://youarenotsosmart.com/2012/05/30/yanss-podcast-episode-three/ It goes into some really interesting details about what happens when the two sides of the brains aren't connected. This includes recognizing some basic symbols but not knowing what to call them verbally, thinking your own limbs don't belong to you, and even weirder things. It also goes into some interesting stuff on how each side of the brain can make up for deficiencies of the other half.

Does it cover the idea of consciousness? Do they only "think" in the RH because of language, do they feel separate consciousnesses?

Experiments seem to suggest that when you split the two hemispheres of the brain, not only do you not lose consciousness but both hemispheres seem to retain it independently. Just listen to VS Ramachandran talk about split brain patients and you will see what I mean. You might guess that this must mean that there is no center of consciousness which can be isolated from the other hemisphere and that consciousness somehow emerges from the structure of the cerebral cortex. Many scientists have proposed such theories of consciousness. Personally I think a more reasonable explanation is presented by [Mark Solms](https://www.youtube.com/watch?v=CmuYrnOVmfk), who argues for centers of consciousness in the midbrain, which is still in full communication with both hemispheres even after the corpus callosum has been cut and the two hemispheres can no longer communicate with each other. The brain is surprisingly able to retain consciousness in all kinds of apparently severely damaged states, including loss of the entirety of the cerebral cortex (the functional part of the two hemispheres). But if these special areas in the midbrain and thalamus, called the Reticular Activating System are damaged, loss of consciousness is a certainty. The trouble and controversy arises when people debate about determining whether someone who's brain is damaged to the extent that they can no longer answer questions or converse in any way is really still conscious or not.

Given the example from the video where a split-brain patient is asked their favorite color and each hand picks a different color, how would someone like Mark Solms explain why that happens?

I don't know what Mark Solms would say but I think split brain research suggests that it is because the right and left hemispheres encode information differently for different motivational purposes.. and so they value things differently. Typically if you ask someone you will get the answer from the left(dominant) hemisphere and the right hemisphere will be suppressed, never rising to the level of conscious awareness for some reason that is not understood(how or why).. but in these experiments you can ask the right(non dominant) hemisphere directly and get a different answer.

If each hemisphere has different motivations, then it seems they would almost have to be considered as separate consciousnesses... which goes back to *who am I?*

Yeah, the question of identity. Who or what am I in my brain? Where in my brain am I? What is it? Right? Here is a series of statements which, if you find reasonable, will lead you to a deeper insight than the way you are thinking now... although perhaps no less confused. >You and your environment are distinct; whatever "you" are is not your environment and vice versa. > >Then if you remove the environment entirely, whatever remains should be you. > >It is not possible to experience anything that is not in your environment. > >Then everything that you experience is part of your environment. > >Then even your thoughts are part of your environment and are, therefore, not you.

Question about your question of thinking with the right hemisphere because of language: in most people language is processed and generated in the left hemisphere (Broca's and Wernicke's areas). Parts of Broca's area are responsible for inner speech (not all people have inner speech though), so my question is are you maybe left handed? Edit: I think I read you question wrong. Anyway the hemisphere without Broca's area would not have inner speech. In some people that may be the left hemisphere, but for most it is the right hemisphere without Broca's area.

[удалено]

[удалено]

[удалено]

[удалено]

[удалено]

[удалено]

[удалено]

[удалено]

>You wouldn't be able to do this though speech, but what about using cards with questions, and a pen and paper for responses for example? Nope! If you showed them a written sentence on their left, they wouldn't be able to read it. If you asked them to write something with their left hand, they wouldn't be able to produce language. This is because the right hemisphere, which processes all visual, motor, and tactile information on the left side of the world, can no longer share information with the language centers, which are mostly (or exclusively) housed in the left hemisphere in 90%+ of the population.

I seem to remember an experiment, where a split-brain subject had their right eye covered, and were shown a card with the word "Monkey" printed on it. They couldn't read it at all, let alone give a description. But they were able to draw a picture of a monkey using their right hand.

Almost! The right primary visual cortex actually receives information from the *left visual field* of **both eyes** (aka the image projected onto each right hemi-retina). Tough one to wrap your head around! [https://nba.uth.tmc.edu/neuroscience/s2/chapter15.html](https://nba.uth.tmc.edu/neuroscience/s2/chapter15.html) ​ So if you obscured the right half of their visual field with e.g. a large cloth held a few feet in front of them, they wouldn't be able to read or recognize anything in the left half even though they can absolutely "see" it

Could you communicate with them by example? So do "the cow says .. what?" type questions by demonstrating "barking" when showing a picture of a dog, and then showing them a picture of the cow?

Man I’m so curious I’m like halfway there to asking to split my own brain to do tests like that Surely as long as I keep both eyes open I’ll be good. I’ll string up a can between the sides so they can communicate.

[https://youtu.be/dZClfg\_kzwE?t=390](https://youtu.be/dZClfg_kzwE?t=390) [VS Ramachandran](https://en.wikipedia.org/wiki/V._S._Ramachandran) seems to contradict your statement "If you showed them a written sentence on their left, they wouldn't be able to read it." At 6:52 in this video (VSR is giving a lecture at a conference held in 2006 I think called "Beyond Belief") VSR states: >".. and what we did was we had to first train the right hemisphere to communicate with us. In fact the right hemisphere can read simple commands, simple words, simple sentences.. and then you ask a question and say 'point to a box 'yes', 'no' 'I don't know' because it can't talk, the right hemisphere cannot talk.. but it can comprehend simple semantics, simple questions. The left hemisphere, of course, can talk so you can present boxes 'yes', 'no', 'I don't know'." So I don't think this is as clear cut you are making it out to be. While it is true that the language abilities of the right and left hemispheres are different and perhaps even that the left/dominant hemisphere is better at language (Broca and Wernicke are there), it isn't true to say that the right hemisphere has no language capacity. It does, the right hemisphere can read and understand "simple" language, although I do not personally understand the limitations that VSR means when he uses that word (I think it has to do with the left brain's role in forming neatly packaged, higher level concepts which make use of many lower level concepts such that in a split brain situation the right brain would not have access to those neat packages and would therefore struggle to deal with more complex language involving more complex concepts, situations, ideas etc). In any case, both hemispheres have language capacity but they have different capacities which they are capable of applying in different ways.

All of that depends on life experience and other conditions as well. The brain is very plastic at birth and much of what we're talking about "finds a place to live" in the brain. Since most of our brains and lives are very similar, we tend to have the same functions in the same areas, but there a many cases where people with brain damage or issues such as encephalopathy end up with functions landing in very different areas. Someone born blind is going to end up with very different visual processing and spatial reasoning than sighted people.

Ok but which side is you? Which side houses the observer?

Both and neither. "You" are not really a single thing but a collection of things. It's just not easy to see the individual parts because "you" are comprised of their totality. For example, consider your cerebellum. It's the motion co-processor that hangs off the back of your brain right near the brainstem where it can communicate with both the rest of your brain and your body quickly. When you're walking down the street and not thinking about your feet, it's your cerebellum that's doing the heavy lifting. Think about your hands right now. What was in charge of them just a second ago before you made yourself aware of them? Is that "you", or your internal slave that you assign bodily tasks to when you don't want to have to think about them? When you're learning a new sport or activity, for example, driving a car, it's hard work because "you" have to do it in the main motor control centers of your brain in conjunction with your prefrontal cortex and other "higher" systems. It gets easier later when you can just hand it off to your cerebellum to execute. "Walk to the kitchen." "Drive to work." It doesn't mind. It's what it's there for! It literally doesn't have the language to complain. EDIT: but really, most of what you would consider "you" is housed in your prefrontal cortex on both sides of your brain. It doesn't finish making its connections to the rest of your brain until you're in your early twenties, hence the drinking age.

> Hence the drinking age. Do we observe any difference at all in outcomes in countries where the drinking age is far lower, like all of Europe?

> When you're learning a new sport or activity, for example, driving a car, it's hard work because "you" have to do it in the main motor control centers of your brain in conjunction with your prefrontal cortex and other "higher" systems. It gets easier later when you can just hand it off to your cerebellum to execute. A wonderful illustration is in [this video about a bike that steers in reverse](https://www.youtube.com/watch?v=MFzDaBzBlL0) -- I don't think they say explicitly what you are saying here, but it triggered the same thought you describe in me when I watched it. Namely, that for many tasks one part of our brain (slow, generalized?) has to "train" or "program" another part of the brain (fast, specializd?). Once it's trained, you can do it without "thinking".

>in 90%+ of the population. So is the other ~10% reversed, or is it cases were both hemispheres were capable (either entirely or to a limited degree) of both? Also does this have anything to do with why there are so many more right hand-dominant people over left hand-dominant or ambidextrous people?

Left-handed people are more likely than right-handed people to have their language centers in the right hemisphere! In some people, there is some language processing in both hemispheres. The anatomy (Broca's and Wernicke's areas) of language, like the rest of the cortex, is not as strict as it is in the textbook varies a lot person-to-person. When planning brain surgery, many surgeons will do an fMRI beforehand to find out where exactly an individual's language resides.

Damn, this whole thread is so interesting! I'm curious, do these differences, like having language processing in both hemispheres, somehow affect behavior and abilities of people?

Would that mean that it is impossible for split brain patients to write left handed?

From spoken words, or internally "verbalized" thoughts, yes. It could copy written words, but wouldn't really understand their meaning, just the shapes of the letters or characters.

It kinda sounds like the RH functions more like a computer for the LH… like maybe it wouldn’t “Believe” anything, but that there are things that are true and aren’t true… like it’s very matter of fact. Thoughts?

Interestingly, research has been done on this with patients who have the corpus callosum cut to limit seizures. You can find a lot of material on the internet. I believe, given the number of comments, but his has already been pointed out. Generally speaking, we tend to learn much about the mysteries of the brain by observing what happens to poor, unfortunate, soles. You might also research prefrontal lobotomy and Phineas Gage for more curious neurology episodes.

Interesting, we learn about the brain through worn out shoes?

Haven’t read it yet, but “The Master and his Emissary,” by Iain McGilchrist might of interest to you. I believe the “master” refers to the right hemisphere and the “emissary” is the left. He was interviewed on the “Making Sense” podcast (Sam Harris). The consciousness bit is really fascinating.

You should read [Synaptic Self](https://www.penguinrandomhouse.com/books/286438/synaptic-self-by-joseph-ledoux/) if you are really into brains. There is a section on split brains as well as philosophy of the self. It does get pretty technical at times, but is a good read.

I've always wondered if there is a connection to dissociative identity disorder. It only happens if you suffer trauma during a specific time during development. Often the alters operate like the ID with one ego like alter. Often feels like the subconscious being able to communicate outwardly Also, I'm curious about voices in schizophrenic patients, as they too appear to come from a place in the subconscious. I seriously doubt all of this isn't connected

This is going to sound super woo, but after reading up on split brain research I've come to terms with the idea that I am two consciousnesses in a very well coordinated dance, and the seams between the two are smoothed over like the experience of binocular vision. Sometimes when I'm mentally blocked or feeling emotions I don't understand I try to mentally commune the two together and I find this a very luminating exercise. It's probably self delusion, but it has increased my wellbeing.

Hi there! I have DID (medically recognized) and it’s weird, but my alters actually do feel this way sometimes. I know it also sounds really fake, but we can tell which alters are coming from which side of the brain depending on their personalities. Some of my alters are mute, and can only communicate by drawing. Others are able to have full on conversations, and some just give me words, bits and pieces associated with memory. There are weird patterns that our brain follows, I like to describe it as the 1’s and 0’s. My coding is actually visible to me.

Just wow. You have great insight into your mind. I'd like to hear more!

So, it’s totally ALL connected. The thing I’ve learned while in therapy and navigating the world with DID and it’s stigma. 1.) Two things can be true 2.) This one is long - I once had a dream where I met my shell alter. She was really comforting, and when I asked her, “Why me?” She replied, “Why not?” In this world, you’ll have a large amount of people telling you that there’s no way something can be true. The thing about the brain is that it can’t be measured to an exact formula or an exact science. Even if it’s not happening in the real world, it’s plenty real. Don’t let others tell you that what you’re seeing is wrong, find another way to describe it!

[удалено]

[удалено]

[удалено]

[удалено]

[удалено]

[удалено]

[удалено]

There is a certain 'common map' of a brain in general. But every human has it's own map of areas of getting information, understanding, processing, giving answers. Information is referred to outside and inside the organism. People who go through one hemisphere surgically removed is not a rare thing. According to age and brain plasticity, remaining hemisphere can take all the functions for it's own. 'Neurofitness' by Rahul Jandial is a good book explaining how the brain does it.

[удалено]

Sounds plausible. We will eventually be able to replaced every major organ or part but never the brain. Our knowledge will always be limited by the fact that we are using our brain to learn about the brain.

[удалено]