When You Split the Brain, Do You Split the Person? (aeon.co) 124
An anonymous reader shares an article: The brain is perhaps the most complex machine in the Universe. It consists of two cerebral hemispheres, each with many different modules. Fortunately, all these separate parts are not autonomous agents. They are highly interconnected, all working in harmony to create one unique being: you. But what would happen if we destroyed this harmony? What if some modules start operating independently from the rest? Interestingly, this is not just a thought experiment; for some people, it is reality. In so-called 'split-brain' patients, the corpus callosum -- the highway for communication between the left and the right cerebral hemispheres -- is surgically severed to halt otherwise intractable epilepsy. [...] What, then, happens to the person? If the parts are no longer synchronised, does the brain still produce one person? The neuroscientists Roger Sperry and Michael Gazzaniga set out to investigate this issue in the 1960s and '70s, and found astonishing data suggesting that when you split the brain, you split the person as well. Sperry won the Nobel prize in medicine for his split-brain work in 1981. [...] Case closed? Not to me. [...] To try to get to the bottom of things, my team at the University of Amsterdam re-visited this fundamental issue by testing two split-brain patients, evaluating whether they could respond accurately to objects in the left visual field (perceived by the right brain) while also responding verbally or with the right hand (controlled by the left brain). Astonishingly, in these two patients, we found something completely different than Sperry and Gazzaniga before us. Both patients showed full awareness of presence and location of stimuli throughout the entire visual field -- right and left, both.
On second thought (Score:5, Funny)
The brain is perhaps the most complex machine in the Universe
That reminds me of an Emo Philips joke: I used to think the brain was the most amazing thing in the universe. Then I remembered what was telling me that.
Re:On second thought (Score:5, Insightful)
An alternative is:
If the human brain was simple enough for us to understand, we'd be so simple we couldn't.
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While I eat it... With ketchup.
Thats disgusting! Ketchup would ruin the flavor.
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I have half a mind to argue this point with the author.
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I was with you, until you said "to".
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Hence the usage of the word "perhaps." Calm down.
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True. "Perhaps" makes the sentence not incorrect. It's also not very meaningful either.
I have a friend named Jimmy who is 6'1". I don't know anyone else named Jimmy, so I could say Jimmy is perhaps the tallest Jimmy in the world. Bit of a pointless statement considering I don't know how many Jimmys there are; the odds are likely there is a Jimmy taller because the world is full of Jimmys and people over 6'1".
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Anybody over 6'1" would be called 'Big Jim", anybody under 5'7" would be called "little Jimmy"
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You don't mess around with Jim.
Uptown Got Its Hustlers, the Bow'ry Got Its Bums
Forty Second Street Got Big Jim Walker
He's A Pool Shootin' Son Of A Gun
Yeah He's Big & Dumb As A Man Can Come
But He's Stronger Than A Country Hoss
And When The Bad Folks All Get Together At Night
You Know They All Call Big Jim "Boss"
Just Because, And They Say
You Don't Tug On Superman's Cape
You Don't Spit Into The Wind
You Don't Pull The Mask Off The Old Lone Ranger
And You Don't Mess Around With Jim
Well Out Of South Alabama Came
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Little Jim: How's the weather up there?
Big Jim: Raining!
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It's all about scale and sample size. In your example, you have a sample size of 1. In the summary's statement about the human brain, we have a sample size of X, where X is the number of complex machines that we're (human kind) aware of in the known universe, and X is significantly larger than 1.
This is the purpose of the usage of 'perhaps', which etymologically means by chance. The writer is, based on knowledge to date, willing to wager that the human brain is the most complex machine in the universe.
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Jimmy may only be one person out of one million people named Jimmy. So makes up one millionth of all Jimmys.
The machines we know all come from one planet. Of all the billions of galaxies each of which contrain trillions of stars we have "perhaps" encountered less than one millionth of all machines in the universe.
Jimmy is "perhaps" closer to representing all of his kind than earth machines are to representing all machines in the Universe.
Unless there is another planet with people on it and some are calle
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Right. And with Kimmel, Fallon, Carter, and John (mmm, just had a JJ sandwich for lunch: #11 on wheat with cucumbers and sauce.), you have reason to believe that your Jimmy is not the only one. This would make the statement of your Jimmy being the tallest an absurd one.
The life on our planet is the only life known to us. It's reasonable to suspect there is other life and, possibly, more complex br
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I think you miss the point.
There could be one million Jimmys- my Jimmy is but one of them. Therefore one millionth of all Jimmys. I never said there was only one Jimmy.
Earth is but one of potentially trillions of planets with machines on it- arguable a much smaller percentage than Jimmys.
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Machine: a living organism or one of its functional systems [merriam-webster.com]
Pedantic. Admittedly, so is this entire thread.
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By *your* definition...
Recommended... (Score:1)
If you like this kind of stuff, read Phantoms in the Brain: Probing the Mysteries of the Human Mind by V. S. Ramachandran. Good book.
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If they took half my brain and transplanted it to a new body, which one would be me?
Whichever side stayed inside, scared to ask out a girl.
I'm sorry, that was mean of me. Of my mean lobe.
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If they took half my brain and transplanted it to a new body, which one would be me?
Neither and both.
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That new body is a zombie, right?
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But is that the smartest, most enlightening thing to do? Does looking at them instead of him tell you more information, the same, or less?
Geez, I sometimes model people differently even without malfunctions quite like that happening. When my wife's on her period, there's a few days when she's unusually paranoid, hostile, desperately itching to turn any slightest adversity (e.g. that douchebag cut m
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That's the time of the month, you spend more time with the side girlfriend who isn't on the rag.....
You just gotta match them to make sure neither has period
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If a person has Dissociative Identity Disorder (Multiple Personality Disorder) we still see him as one person..
That's because DID is just one person with a fully connected but traumatized brain
Cutting a brain in half does not make a difference.
It absolutely does when you are severing the communications between those two halves, but leaving both perfectly functional.
There have been people where they lost half their brain. They do not become half a person. They are just the same person with, in some cases, a complete different mentality.
They have a different mentality because literally half of it has been severed - they really are a half/different person
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> we still see him as one person
From a neurological perspective, this is a simplistic view. One personality, seems more appropriate.
"A person is not a single entity of a single mind: a human is built of several parts, all of which compete to steer the ship of state." - David Eagleman
Jordan Peterson has also said as much (I don't have the exact quote). I'm sure there's more than a handful of papers, to find, on the subject of personality composition.
> Cutting a brain in half does not make a difference.
Earlier (Score:5, Informative)
Earlier experiments used a partition to separate the left and right visual fields. One experiment I recall reading about was done like this: On one side of the partition they would place an implement, such as a fork. They would then have the subject pick up the implement in one hand and ask them to identify it, and do various things with it. The results were markedly different depending on which side of the partition, and therefore which eye and which hand, were engaged.
Here is [washington.edu] some general information on the early experiments.
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In the same experiment the test subject tried to identify a hair brush but could not
until the subject flicked the bristles
the subject was able to identify the brush from the sound which was heard by the other half of his brain
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Also, N = 3.
When you split the brain... (Score:1)
Re:When you split the brain... (Score:4, Informative)
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Your absolute judgement has no scientific basis in observable facts. Are you a religious fanatic?
Split Pea (Score:2)
I don't know much about the brain but I do know if you split peas you make soup.
Brain - multi core CPU (Score:3, Insightful)
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It's estimated that the brain is arranged into around 1500 "cortical units" each of which contribute to about 130 different purposes (like being able to understand a story, identify concave regions in space, like hallways or cupboards). So it's really more a supercomputer than a multi-core CPU's. Diffusion MRI gives up a layout of http://static.wixstatic.com/media/0eecff_7acaecfbb8c04605baa48ff8454004ff.jpg [slashdot.org]
The hardest part is keeping everything in synchronization. That's solved by having brainwaves.
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I find it difficult to believe that two COMPLETELY SEPARATE subsystems (left brand with right eye vs. right brain with left eye) somehow "magically" communicate.
They're not "COMPLETELY SEPARATE". I'm no brain scientist, but I know the brain works somewhat like a very complex network. If a network had a multi-master core, and you severed the large interconnect between them, the network would be degraded but would be (generally speaking) be able to route around the problem.
Furthermore, in patients with half a brain, generally speaking, they are eventually able to regain control of both sides of their body, at least to some extent. In Dr. Gary Mathern's TEDx talk, he
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Re:Religious Bias in New Study? (Score:5, Informative)
The corpus callosum isn't the only connection between the left and right half of the brain.
The architecture of the human brain is a bit like an onion; at the core is the basal ganlia -- also popularly known as the "reptilian brain". Outside/above that is the limbic system, called the "paleomammalian complex" in the triune brain theory. Above that is the neocortex, the part we tend to indentify ourselves with because it does all the cool stuff that more primitive organisms can't, like language.
The corpus callosum sits roughly in the middle of the limbic system -- the middle of the middle if you will. Just above it is the cingulate gyrus, responsible for processing emotions, learning, linking behavior to goals. The cingulate gyrus is the anatomicaly lowest part of the brain that doesn't have its own connections between hemispheres. I find that fascinating and suggestive. Immediately below the corpus callosum is the septum pellucidum, which is a thin, midline structure. Every part of the brain below the septum pellucidum is richly connected across sides.
This situation is like a company run by partners. The partners don't talk to each other, but they share subordinates, including a secretary who keeps them up to date on what each other is doing. The secretary quits, and the company is at least temporarily less coordinated, but the other subordinates still talk to each other and over time may take up some of the communication burden.
One of the big difference in brain science today from when I studied it thirty years ago is that we know the brain is much more plastic than we ever imagined. There have been well-documented cases of people with brain injuries doing things they taught me was impossible back then, like people who lost an entire brain hemisphere regaining some motor control on the affected side. The only way this would be physically possible is for the remaining hemisphere to radically remodel itself.
Anyhow cross visual field object awareness is a good candidate for function restoration, because the nerves from the eyes enter the brain well below the level of the corpus callosum; there are no direct connections from the optic nerves to the cortex. How that awareness comes about/is restored is an open question. It could be that the cortexes develop other way of communicating, or it could be that the hemisphere you're talking to develops awareness of stuff that would normally be processed by the other side.
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You could think of it as two-core CPU with a dedicated bus for maintaining cache coherency. If that bus stops working, you could still use the CPU, but you'd have to handle cache coherency externally by bus snooping or per-page reader-writer locks on main memory or some other scheme. :-)
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The optic nerves actually cross over at the front of the brain. This is required to implement the brainware equivalent of Fourier transforms and signal processing (photometric stereo, edge detection, distance estimation).
Consider if you will (Score:1)
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That the brain is approximately like jello in texture.
Yes, but it's healthier to eat; no artificial colours and fewer sweeteners.
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That's why I only eat vegan's brains, even though it's like eating Quorn in place of real meat.
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That the brain is approximately like jello in texture.
Yes, but it's healthier to eat; no artificial colours and fewer sweeteners.
It's good brain food. :-)
The nervous system connects the two halves (Score:3)
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No but time would.
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Valproic acid has been shown to generate plasticity in some individuals, allowing them to learn how to match pitch much later in life than has ever been demonstrated. Wondering if it could help with split brain patients...
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Actually, it is a possible explanation only. More research is needed before an actual explanation can be found.
You are two ... (Score:5, Informative)
the brain creates you? (Score:1)
A self, an individual, is an existing subject. A thought about something does not mean it exists.
E.g. I can think about unicorns all day, but that doesn't mean unicorns exist.
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Yeah, people have been arguing about that stuff since Descartes.
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And people have been delaying living since long before him
Some are born without a corpus callosum (Score:5, Interesting)
I lived across the street from a young girl - I'll call her 'Sandra' - who had grown into her mid-to-late teens when I moved away. She had been born without a corpus callosum, and her parents were warned that she would never be anything approaching normal, and might not even live.
Apparently her parents did something right, or she herself possessed some kind of will or magic that got her beyond the difficulty. Other people who had kids born with the same lack would ask Sandra's parents for advice and support. Sandra was always a bit quirky, and when she was younger I always had the sense that she wasn't quite normal, even before I knew her history. But she was sweet and funny, she made pretty much normal progress in school, and she grew into a lovely young woman who didn't wasn't out of place among her peers in any significant way.
So I'm not surprised at these new findings. The human brain seems to be very good at routing around damage in ways that we don't yet understand.
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Imagine being this guy, born without much brain at all, and yet not knowing it until much later in life:
http://www.rifters.com/crawl/?... [rifters.com]
The human brain is very good at doing the things a brain does, sometimes even when all of the parts we think are necessary are not there in the proper proportions or even there at all.
Short Answer? (Score:2)
Ghost Hand syndrome (Score:2)
I remember seeing studies about this stuff when I was a kid.. Still creeps me out.
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I think I saw recently that some of the Ghost Limb issues can be addressed by the ways the nerves were severed. I can't recall the source now, so I could be wrong, but I seem to recall that the effect could be cured by trimming or modifying the damaged nerve endings, and they would stop reporting phantom limbs.
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I think I saw recently that some of the Ghost Limb issues can be addressed by the ways the nerves were severed. I can't recall the source now, so I could be wrong, but I seem to recall that the effect could be cured by trimming or modifying the damaged nerve endings, and they would stop reporting phantom limbs.
Not Ghost Limb. Ghost Hand... They're different issues. Ghost Hans is also known as Alien Hand Syndrome. Its' where a limb, usually your hand and arm seemingly are acting of their own will and not of your conscious control. It's usually a condition that people who have had certain trauma or hemi sphere separation experience due to the splitting of the parts of the mind from being as connected as they were.
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Ah, whoops. Thanks for the clarification.
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What happens with phantom limbs is twofold:
First, the nervous system uses both positive ("there's something happening") and negative ("there's nothing happening") signals. If you amputate a limb, the brain stops receiving both types of signals, and the absence of negative signals is interpreted as sensations from the limb.
Second, the boundaries between the parts of the brain controlling different parts of the body isn't sharp. If you cut off somebody's hand, signals from other areas such as the "arm" part
They actually *are* autonomous agents (Score:5, Interesting)
FTH (and FTA):
"Fortunately, all these separate parts are not autonomous agents. They are highly interconnected, all working in harmony to create one unique being: you."
Almost none of that is true: You aren't unique. You aren't particularly highly interconnected. You aren't in self-harmony. You aren't a single "being". In fact, there are more bacterial cells in "you" human cells in "you"...and many peer-reviewed papers confirm that those bacteria do contribute to determining "your" behavior. And those autonomous agents inside of you? They are pretty darned autonomous.
My freshman psych professor explained it to us this way: "There are a whole lot of different behaviors we can observe. Different parts of the organism have different jobs. One of those jobs is to make up stories. We call that one consciousness. The illusion that each healthy uninjured human body has one integrated consciousness is a complete fantasy. Injuries and other pathologies expose this fact in interesting ways, but fragmented and incomplete consciousness is the normal way of being for all of us."
A good way to see the separation is to compare desire vs behavior. If there was one fully integrated and aware "consciousness", then desire and behavior would always be consistent. They're not. Not even close.
Consider things we do even though we'd prefer not to: Habits, compulsions, and addictions. Tobacco smoking could be any of those. It's not hard to find a smoker who will tell you "I want to stop smoking".
Or neurological phenomena, for example "the yips" (google it, it's a golf thing).
On a more positive note, consider practiced skills--like touch-typing, playing musical instruments, batting a baseball, rollerblading, etc. You can't consciously decide "I will skillfully perform this act" and *poof* it's done.
There's something in you that does (or does not) those things. But it's not the thing that's speaking to the person next to you.
Lovecraft put it quite nicely:
“The most merciful thing in the world, I think, is the inability of the human mind to correlate all its contents. We live on a placid island of ignorance in the midst of black seas of infinity, and it was not meant that we should voyage far.”
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The illusion that each healthy uninjured human body has one integrated consciousness is a complete fantasy. Injuries and other pathologies expose this fact in interesting ways, but fragmented and incomplete consciousness is the normal way of being for all of us."
A good way to see the separation is to compare desire vs behavior.
This might be simply an artifact of the way my brain works but I'll put it out here and you can try it for yourselves...
Perhaps a simpler way of seeing this separation is to do the following: Lie on one side for a few minutes, and let your mind find a train of thought. Follow that train for a little while. Now, roll over and lie on your other side. After you're comfortably settled ask yourself: Are your thoughts still on the same track?
For me the answer is invariably "no". I suspect it has to do with blood
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Where's the damn "like" button?
Seriously though, I have no mod points, otherwise you would get some. Hacking your own meat is what I like to refer to at my "working definition of free will."
Acknowledge you are not in control of most of the things you do. Your physical stuff has predilections and propensities that are, in most ways, hidden from your conscious thought. In fact, most of the "thinking" done in your head is non-verbal. You can't directly address those parts of your brain, but they sure can d
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good thing your freshman psych professor knows everything or he could possibly have been wrong, and then you would be wrong as well.
I always find it funny that we think we can understand the brain with the brain, how can something understand that which it is itself using to understand?
all current progress has only gotten us to guessing, and we'll keep on guessing for a long time, i don't know if we can ever truly "know" how we work.
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"But it's not the thing that's speaking to the person next to you."
Well, maybe.
I read a small number of books to my kids, with funny voices and everything, so many times that I could stop thinking about the process at all. My eye's scanned the words on the page, my voice made the noises, but I was off thinking about something else. The rest of my brain had pretty much automated the process.
Sometimes my internal thought process would direct my eyes across the room to look at something, and I'd wonder why
The Man Without A Brain (Score:3)
The guy with a tiny brain [newscientist.com] shows that we don't know a lot about the mind/body connection. That this guy was able to function as a normal human being is really astonishing.
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Without getting all religious, there is some evidence to suggest that you (the entity that is self-aware) are not the brain.
Generally speaking, doctors and medical scientists are firmly in the you=brain camp. One exception is cardiologists or ER physicians who've done a lot of defibrillation on heart attack victims. Do enough of them and you will get people who go through a near-death experience. Get enough people with NDE and sooner or later you will get a patient who describes seeing the operating room f
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The guy with a tiny brain [newscientist.com] shows that we don't know a lot about the mind/body connection. That this guy was able to function as a normal human being is really astonishing.
Wow... where is your evidence of this thing you refer to as "mind"? Please show peer reviewed cognitive science research the substantiates your claim. To my knowledge, there is no evidence of a "ghost in the machine". See: Daniel Dennett and Sam Harris for example.
fuzzy logic (Score:3)
Most interesting questions are not defined precisely enough to have exact answers. The answer is fuzzy. In this example, the word "person" doesn't have a precise meaning, but just some vague context-sensitive meaning which we mostly agree on based on our shared upbringing. In some cases, some authority will make a more precise but arbitrary definition for the purposes of law. For example, legally blind. Legal person. So, if you split the brain, do you split the person? It depends on if some authoritative body declares it to be so.
Stone throwing devils (Score:2)
Brain halves are not completely split (Score:2)
Old news (Score:2)
This press release [wikipedia.org] from January the year. Same university. Not to say that it isn't interesting research, it is, but it is not news.
Cerebellum is still linked (Score:2)
You split one brain structure, not all neuro (Score:5, Interesting)
They split one brain structure, not the whole neurological system. I don't think they even split the whole brain, so it could be that lower level brain structures are picking up the slack. At the very least we know they didn't split the spine since that'd kill you. It's conceivable that these lower levels of the brain and peripheral nerves are an integral part of being a person. I've heard that the heart actually turns out to have more to do with personality than modern medicine once thought. It's not just a stupid pump. Users of artificial hearts report that it lacks that certain something. Receivers of transplanted organs sometimes acquire traits from the donor, such as food preferences. You wouldn't think such traits could be conferred via those organs. Your sense of self may be more "distributed" than some of us think.
n = 2 and no details and no peer review (Score:1)
What could go wrong?
Does it matter? (Score:2)
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Science might prove that the soul does not exist.
IE: If Cryonics ever proves that resuscitation is possible, does that mean the human soul hangs out until the body is resuscitated? How did it know this would happen and if it never happens does this mean your soul could be trapped forever waiting for an event that never happens? People have been resuscitated after life functions have stopped for a short period of time. Is there a time limit where the soul finally decides to leave?