hypothetical question #2

[zidane1strife]

What if?

What if using advanced technology you split your brain in two(if advanced enough assume no neurons are lost in the process.), you clone a body with the neurons properly altered/trained to function appropriately with the new half brain... also assume the tech is advanced enough to allow survival with normal human functions...

Thus we've got two bodies each with half your brain... each human...

Who are you? Which are you?

PS Oh, and if you're going to argue that you are no more, or that you're dead... let's think about those people who've survived stroke and lived to tell about it... I'm sure there are some that might've lost nearly half their brain, and still are the same person(with possible behavior alterations.)yet you wouldn't argue that they're dead.(Oh, and there are people with just half the brain that can live and function normaly.)

As always, comments greatly appreciated!!!

edii

 

[Nathan]

You could just cut their corpus callosum, and leave both halves in the same body. This has happened on the odd occasion, with very interesting results. It turns out that each side of our brain has a different personality. Usually the dominant personality is in control, but cutting the corpus callosum allows each side to act independantly. Afflicted people have reported that one side of their body will try to put clothes on while the other side is trying to take them off.

 

[pax]

There was that one kid who got shot in the head and litterally half his brain was blown away but he survived. He had been working in fast food joint late one night and his manager mistook him for a theif. When cells are lost some of the brains functions and thinking are rerouted into the surviving areas. We see this in stroke victims a lot.

Tho relearning is nowhere near as possible as the original full healthy brain I suspect in your scenario we'd see the creation of twins.

 

[OpenGL guy]

You could just cut their corpus callosum, and leave both halves in the same body. This has happened on the odd occasion, with very interesting results. It turns out that each side of our brain has a different personality. Usually the dominant personality is in control, but cutting the corpus callosum allows each side to act independantly. Afflicted people have reported that one side of their body will try to put clothes on while the other side is trying to take them off.

This severing of the corpus callosum was done in an effect to treat epilepsy. The hope was that a siezure wouldn't spread from one half of the brain to the other. While this seemed to have worked, it had some weird side effects as Nathan mentioned.

Because of the way our nervous system is constructed, below the neck, the left half of the brain controls the right half of the body and the right half of the brain controls the left half of the body. The eyes and ears are controlled by the obvious half of the brain as they have a direct connection. The mouth, however, is largely under control of the left half of the brain (if I remember correctly), so the right half of the brain can't express itself vocally. I recall reading about people who'd had the corpus callosum severed and they couldn't identify the shape of an object placed in their left hand if they couldn't see it. I also recall reading about people being unable to control the left half of their body (arm flailing or hitting themselves). That would be a weird experience...

The original poster's question reminded me of a thought experiment I had read about in philosophy many years ago. A man has to go into a mine to do repairs on some equipment, however there is radiation that destroys brain tissue present. Doctors remove the man's brain, place it into a tank with radio transmitters/receivers to send commands to his body. When the guy wakes up he can't tell that anything is changed, except that when he looks into a tank he sees a brain that people tell him is his own. As a backup, engineers have also created a computer to exactly simulate the man's brain. It too is also hooked up the body, but only one can be in control at a time. The man is incredulous and says, "I don't believe it." while flipping the switch. The sentence is completed without any interruption whatsoever. Anyway, the man sends his body down to do the repairs and all is good. Many years later the body is giving an interview while the brain vacations in the Bahamas. Someone asks when was the last time he "flipped the switch". He replies, "You know, I've forgotten" and flips the switch. "Oh my god! I'm free! Don't you ever touch that switch again!"



So the question remains: What is self?

 

[Vince]

Who are you? Which are you?

PS Oh, and if you're going to argue that you are no more, or that you're dead... let's think about those people who've survived stroke and lived to tell about it... I'm sure there are some that might've lost nearly half their brain, and still are the same person(with possible behavior alterations.)yet you wouldn't argue that they're dead.(Oh, and there are people with just half the brain that can live and function normaly.

This is actually an already active field in Neuropsychology/Neurology. There have been split-brain studies since the 1940s when von Wagenen and Harren first severed the hemispheres to prevent epilepsy from "spreading" in an electrical storm type movement across the Corpus Callosum/Cerebral Commisure. Not much actually happened (he didn't sever the anterior commisure) but in later cases where there was what's called a California/Bogen Series preformed - where they sever the entire length (What von Wagenen did and Nathan refered to is called the Eastern Series) - they found that they could selectivly "teach" each hemisphere independantly by informing each hemisphere via saturating only a specific pathway (eg. custom contact lense or tachtiscope that only lets light enter the extreme right [or left] visual hemisphere is an example).

A neat trial actually used such Bogen Series patient and flased the word "spoon" (maybe it was fork, I dunno) to just the right hemisphere. They subsequently asked them what he saw and he coouldn't articulate it. They then asked them to reach under a cloth and feel for the object seen with his left hand, they could feel out a spoon. Kinda neat experiment that shows language's hemispherical dominance (although not total) and split-brain experiences.

It also dismisses the whole, "if Y has no linguistic capacity, Y isn't conscious" that I keep hearing.

There were similar studies where each segregated hemisphere was shown half a image and, yet, the patient percieved a whole. It's called completion and AFAIK it hasn't been resolved yet.

The biggest philisophical question, as you touched on and I'm sure the likes of Democoder and Fred will jump on, is the concept of self. These studies have basically killed off the Dualist movement in serious circles as in it's pure, Cartesian form, is basically irreconcilable with these studies. Some keep fighting it and coming up with what amounts to bullshit: Puccetti and his two minds/souls, although Eccles and his N-Minds/souls which is kinda ingenius actually. But, it's obvious for many reasons, as noted by many members of this field, that the concept of oneself is dead.

As per your question, it reduces from what's above, but here's an interesting fact, Dolphins sleep only one hemisphere at a time. Are they dead during this period? Of course not.

Tho relearning is nowhere near as possible as the original full healthy brain I suspect in your scenario we'd see the creation of twins.

I don't think twins is the word to use. For all intents and purposes, they would be discrete entities after that P time of seperation. There will be intrinsic differences in comprehension and processing levels, but calling them twins is wrong.

EDIT: Wish I would have seen your post before typing mine when I should be showering and leaving

 

[Nathan]

but here's an interesting fact, Dolphins sleep only one hemisphere at a time.

Another interesting fact. Did you know 99% of facts are made up on the spot? Seriously, how was that one proven? What does the awake hemisphere do while the other is sleeping. Do Dolphins ever appear to sleep? Does it apply to the whales as well? If a dolphin did go to sleep fully, would it drown?

Getting back on topic. If you split a rock in two, do you have two rocks or two halves of a rock? Is one of the rocks more similar to the original than the other? What about if you separate every atom in a rock?

So many questions, so little time.

 

[Vince]

Seriously, how was that one proven?

Well, they asked Flipper to jump if....

Seriously, the EEG's been around since like the 1920's which can differentiate between different states of consciousness. It's really an art form, and you can argue about what it actually represents, the electrogenesis (is is merely spiking neurons? Or is it also intra/extra cellular potential changes due to unrelated reasons?)

IMHO, that questioning of what it's fundimantally measuring is insignifcant for this discussion when you can, with a great degree of certaintly, differentiate between the different states of sleep (including REM and nREM) based on whatever you're measuring. And when ERP (the local kind ) is used, which is basically 50+ EEGs that are filtered and biased, you get a pretty good indication that what you're seeing is what you get.

And this is all by using an old-school technique if you will. Now-a-days, being the advanced people we are, you CT, rCBF, PET or NRM it without a doubt depending on the task and never look back because they're that common.

What does the awake hemisphere do while the other is sleeping. Do Dolphins ever appear to sleep? Does it apply to the whales as well? If a dolphin did go to sleep fully, would it drown?

I'm not a marine biologist, you can look it up as easily as I can. This is something, albeit interesting, that was never covered as.. well.. we don't care

Getting back on topic. If you split a rock in two, do you have two rocks or two halves of a rock? Is one of the rocks more similar to the original than the other? What about if you separate every atom in a rock?

I don't think this is a valid comparason. And if you seperate every particle, then you open up a whole other can of worms.

 

[Nathan]

I don't think this is a valid comparason. And if you seperate every particle, then you open up a whole other can of worms.

Sorry, you have to give a reason why you don't think it's relevant, otherwise I'm still going to assume it is relevant.

I'll even give you a reason why I think it's useful to this discussion.

It's often the case that generalizing a problem yields more insight. One way to make zidane1strife's question more general is to allow the same thing to happen to other animals, and even objects. If you can't decide when a rock is a rock, how can you decide if a person is still the person or someone different?

 

[Vince]

Sorry, you have to give a reason why you don't think it's relevant, otherwise I'm still going to assume it is relevant.

Because QM says that they're then indistinguishable, which means one can argue (if correct or not) that they are all the same particle. Which means that we drag all the great 20th century physicists into a philisophical debate on a topic that is entirely classic in design. Although a few will debate that (Did Wheeler join in this debate somewhat along Walker's stance recently too? I've heard something like that)

It's much easier to look at what we know from the split-brain trials and say that there is no dualist phenomina binding together the hemispheres, but instead you have what we can consider a formerly closed system that is opened and diverges into two distinct entities, with their own diverging temporal paths, after point P of seperation.

 

[zidane1strife]

Suppose the person raped/murdered/mutilated others... prior to the procedure.

What would happen?

Would they both be free?

Would both go to jail?

Would one go to jail and the other remain free?

death sentence?

What if we make their brains regen and cut them in a different manner, and repeat this millions of times... genocide sentence?

ed