Slashdot Mirror
When You Split the Brain, Do You Split the Person? (aeon.co)
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.
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.
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.
If a person has Dissociative Identity Disorder (Multiple Personality Disorder) we still see him as one person. Cutting a brain in half does not make a difference.
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.
So: leave it in the body, two people. Put it in two bodies: one person.
If they are born with two brains and one body, it will be seen as two persons.
These are pretty clear situations that already exist.
I feel as if the person is looking for a solution to a problem that does not exist.
Don't fight for your country, if your country does not fight for you.
I don't know much about the brain but I do know if you split peas you make soup.
"That's the way to do it" - Punch
Brain is more like multi-core CPU with dedicated special-purpose cores. When you split, as research shows us, you still can communicate with "talking persona" and "non-talking persona". So yes, effectively there are two "people", but they always been there. They just no longer coordinate well.
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 some general information on the early experiments.
I've fallen off your lawn, and I can't get up.
That the brain is approximately like jello in texture.
Yes, but it's healthier to eat; no artificial colours and fewer sweeteners.
"That's the way to do it" - Punch
Hence the usage of the word "perhaps." Calm down.
sig: sauer
more prions
Nullius in verba
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".
"That's the way to do it" - Punch
While not as rapid nor efficient, the body's nervous system still connects the two halves of a split brain. It's a slower rural road type of path, that is not as efficient as the expressway connection that was cut. But, it exists and explains why the two halves still communicate, albeit less efficiently.
This isn't a thought experiment though. We have actual split-brain patients and we can see how they react. I'm not sure why you think that this kills the patient either, since for most purposes, such patients act very similarly to how they did before the procedure.
CGP Grey did a nice, insightful piece on this in a 5 minute youtube piece discussing just this thing. I like his videos in general ...
Anybody over 6'1" would be called 'Big Jim", anybody under 5'7" would be called "little Jimmy"
That's why I only eat vegan's brains, even though it's like eating Quorn in place of real meat.
"Wait. Something's happening. It's opening up! My God, it's full of apricots!"
No wonder tech people are so neurotic -trying to think themselves into existence.
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.
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 noted that the tracks from the motor cortex shift in the brain stem such that 90% go to the other side... so there's still 10% going to the same side.
IMO, the premise of the test is flawed. The test assumes a stimuli is only received on one side. To ensure that, we'd have to have a more direct interface to one side of the brain, and it'd have to be smart enough to send/receive intelligible signals. We should retest when we get to that point :-)
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.
'The Economy' is a giant Ponzi scheme whose most pitiable suckers are the youngest among us and the yet-unborn.
Also, N = 3.
Yes
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. He or she is not stating this as fact -- merely submitting it as a possibility. Since it is the most complex machine known to human kind, this is as correct as saying "one of the most", and more correct than saying "perhaps one of the most".
sig: sauer
Looking at the organization that published the study I kind of agree. It looks like some kind of "free thinking" society that doesn't concern itself too much with scientific method.
I remember seeing studies about this stuff when I was a kid.. Still creeps me out.
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.
Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.
Nevertheless, the original question can be answered. When you split the brain, you do not necessarily split the person, but if you use a very sharp blade like that of a katana, chances are high that you will also split the person. You need to use a dull blade or saw and split the brain slowly in order to avoid splitting the person.
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. :-)
It must have been something you assimilated. . . .
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.”
"Reality is that which, when you stop believing in it, doesn't go away." - Philip K. Dick
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 called Jimmy... then all bets are off.
"That's the way to do it" - Punch
Your absolute judgement has no scientific basis in observable facts. Are you a religious fanatic?
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
The guy with a tiny brain 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.
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).
Vintage computer adverts: http://www.vintageadbrowser.com/computers-and-software-ads
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.
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?
Our brains are as large as they are so we can lie, cheat and persuade other humans and so we can throw things. If I want throw a rock and hit something it requires a degree of precision and coordination between my muscles that normally can't be done with nerve cells. The way our nerves work creates to much jitter. To solve this, we have orders of magnitude more nerves controlling our muscles than other mammals, so that the average transmission speed of signals in our nerves much more constant and predictable.
Playing chess, doing calculus or memorizing Pi to 100 digits has no advantage on the plains of Africa. But lying to a woman so I can sleep with is a really good advantage. Although for a woman, being able to figure out if I'm lying or being able to lie to me might be useful. So we get into a mental chess match each trying to outsmart the other and the winner is the one who thinks the most moves ahead.
The net result is we have a lot of excess brain capacity and excess communication pathways for doing almost everything.
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 brains as well, simply because the universe is BIG. But, we have no information available to us that provides for anything more than mere speculation. So, until we do, the human brain is perhaps the most complex machine in the universe ... a very reasonable statement, and no reason for the OP to whine.
sig: sauer
Depends on the regional level of sarcasm...
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 A Country Boy
He Said "I'm Looking For A Man Named Jim
I'm A Pool Shhotin' Boy, My Name Is Willie McCoy
But Down Home They Call Me Slim
Yeah I'm Lookin' For The King Of Forty Second Street
He's Drivin' A Drop Top Cadillac
Last Week He Took All My Money & It May Sound Funny
But I've Come To Get My Money Back"
And Everybody Say "Jack
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 A Hush Fell Over The Room
Jimmy Came Boppin' In Off The Street
And When The Cuttin Was Done The Only Part That Wasn't Bloody
Was The Soles Of The Big Man's Feet
Yeah, He Were Cut In 'Bout A Hundred Places
And He Were Shot In A Couple More
And You Better Believe They Sung A Diff'rent Kind Of Story
When Big Jim Hit The Floor. Oh Now 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
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 Slim"
Yeah, Big Jim Got His Hat, Find Out Where It's At
And Not Hustling People Strange To You
Even If You Do Got A Two-Piece Custom Made Pool Cue
The corpus callosum is not the only connection between the halves of the cerebral cortex. There are all of the lower brain structures. And most modern callosotomies are incomplete. So no surprise that a modern researcher would get different results than the past.
Bruce Perens.
This press release from January the year. Same university. Not to say that it isn't interesting research, it is, but it is not news.
When all you have is a hammer, every problem starts to look like a thumb.
Machine: a living organism or one of its functional systems
Pedantic. Admittedly, so is this entire thread.
sig: sauer
As far as I can say Cerebellum is never split ( https://en.wikipedia.org/wiki/... ). When a brain is "split" they cut the Corpus callosum ( https://en.wikipedia.org/wiki/...). The cerebellum may offer enought connections between the two emispheres
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.
For all intensive purposes, "whom" is no longer a word. That begs the question, "who cares"?
It is perfectly valid for them say, "Perhaps, this is true." Period. The flawed Jimmy example is nothing but a well chosen strawman that compells us to beat at its irrelevant flaw. To say "Perhaps" is to raise a possibility not to draw a conclusion and since probabilities approach but never reach zero it is never incorrect. It is not the fault of the writer that people gloss over words like "Maybe","Perhaps", "Possibly", "Might", and "Probably"; the fault lies with those ignoring these critical words and those who press for absolutes in a world without any... except, perhaps, that one.
Facts, Theories, Hypothesis, Guesses, Speculation, Fabrications, Things you saw with your own eyes, measurements, consensus, these are all things with a probability somewhere less than 100% and more than 0% and that gap, however small, is REAL. We don't know what we don't know and almost all of our certainty and confidence in what we know comes from having internally consistent models. Having consistent measurements with tools which are also built on those models calculated out to higher levels of precision only proves consistency of the model it doesn't decrease the probability there is a bigger picture at play. According to our models, what we are modeling has exists over a such a large span of time, scale, and complexity that in essentially every aspect what is possible for us to observe and measure at this point can't provide us with statistically significant confidence about anything we've concluded regarding reality and its laws.
There is even a significant chance that the stuff of reality is pure probability and is only being temporally fixed into certain laws and patterns of behavior as we speculate and define them. Just like our neurons aggregate for form a larger consciousness we are all neurons in a persistent mind... if we all snapped out of being tomorrow and a new observer appeared at a later point who knows if there would even be gravity in their temporally fixed reality.
"Your hypothesis does not directly explain why results differed so dramatically between patients."
No but time would.
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.
"That's the way to do it" - Punch
Listening to Jim Croce as I type this... well done, sir.
Happiness in intelligent people is the rarest thing I know.
Ernest Hemingway
By *your* definition...
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
What could go wrong?
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. :-)
Check out my sci-fi/humor trilogy at PatriotsBooks.
After splitting the brain the person is dead.
Little Jim: How's the weather up there?
Big Jim: Raining!
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...
When the only tool you have is a claw hammer every problem starts to look like the back of someone's skull.