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Permalink Reply by Nelson on March 24, 2011 at 10:51am

there's a couple of questions here aren't there? let's see...

what part of the brain are you?

well, it depends on what you mean when you say "you".

if you mean, like i think most people do, that "you" would be whatever recognizable "self" you have- your personality; the list of qualities that people might give when asked "who is Samuel Muiruri? what's he like as a person?" then "you" is an emergent property of the brain. you don't exist in any one part of the brain.

this is easy to see from neurology. we've come to learn from studies of diseases of the brain and of injuries to the brain that when certain parts of the brain or damaged by disease or injured it can cause radical changes in the patient's "you" qualities. nice people become aggressive, aggressive, nice. damage to certain areas cause weird perception problems like an inability to recognize faces, a conviction that people you recognize are imposters, not their true selves, and other strange problems. injury and disease can even lead to extreme nymphomania.

so what we've learned is that "you" is the brain, because if you damage much more than even a small part of it what is "you" changes, sometimes drastically.

 

your second question is much harder i think- what is a human really?

well, we all know what we normally take to be a human. but is a dead person still a human? is a person in a vegetative state a human? (and i won't ask other questions that will risk turning this thread into an abortion debate thread. lol) these will seem like insensitive questions to some but they get us to really think about what it means to be human.

but, yes, people can have quite large sections of their brains excised and still be considered human by most people's definition. but i don't think most people would say that the person who had had such a surgery had the same "you" quality that they had had before the surgery.

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Permalink Reply by Doubting Thomas on March 24, 2011 at 12:16pm

dude, you're older and i know smarted however how can half a brain surgery with minimal change state? The interesting part is I got this from 1 show I saw, how much I don't know is boggling

The article by the way says with no change to personality.

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Permalink Reply by Nelson on March 24, 2011 at 1:05pm

the article at the link you cited talks about hemispherectomies on children- "Most Hopkins hemispherectomy patients are five to 10 years old." the article shows the brain's elasticity, it's ability to restructure itself during development. if that's what your question was then surely, as the article makes plain, this can be done. while still developing the brain can do incredible things to restructure itself in order to account for damage. but once the brain is fixed, more or less, as it is in adults, the brain doesn't have that kind of elasticity.

the exception seems to be severing the corpos callosum. since it's just a bridge for communication between the two hemispheres, severing it only keeps the two sides from communicating but leaves each side intact to perform its regular function, albeit with some weird and interesting side-effects.

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Permalink Reply by Dallas the Phallus on March 29, 2011 at 11:16am

Samuel, there apparently is no homunculus in the brain, or no ghost in the machine. In other words, there is no little "self" controlling the actions and thoughts of the brain, or observing the outside world. To my knowledge, we still don’t know exactly what consciousness is – not precisely – but I think that at least one of the predominate theories is that consciousness is not a thing, and not a place in the brain, but rather a process.

Consciousness does not exist in the neurons, but rather the space between the neurons, in those areas where there is an exchange of chemistry and electricity. It is the movement that creates the awareness, not the matter. A dead person has just as much brain matter as a living person, but there is no exchange of chemicals or electricity in their brain, and thus no consciousness.

Our sense of self and ability to engage in self-reflection possibly stems from the evolution of our brain. Much of our brain activity is covert (or unconscious). This accounts for the brains ability to maintain homeostasis in the body (regulating body functions which are unconscious), and for things like reflexes, etc. Things that we don't control.

It appears that our awareness, or conscious brain, exists in the prefrontal neocortex (your forehead), the newest parts of the human brain. Brain scans seem to show that there is a miniscule delay between the brain signals of the paleocortex (the older parts of the brain) that may control things such as motor skills, and the prefrontal cortex. The signals seem to originate in the paleocortex and move towards the neocortex, at which point we become aware of them. This delay seems (perhaps) to be what we sense as an ability to reflect upon our own thoughts and feelings, thus giving us a sense of self.

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Permalink Reply by matt.clerke on June 23, 2011 at 2:11am

"A human is any organism that can successfully produce fertile offspring with us." Sorry but that is a circular definition imo.

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Permalink Reply by Eoganacht on October 12, 2011 at 11:23pm

Who is this 'with us' you are refering to? Otherwise it reads : "A human is any organism that can successfully produce fertile offspring with other humans". Matt is right, this is circular.

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Permalink Reply by Jewelz on October 12, 2011 at 7:25pm

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Permalink Reply by Nelson on October 12, 2011 at 7:30pm

I'm reading Seung's book Connectome, it's fascinating. Looking forward to having him join us on the Think Atheist Radio Show in February when the book has its retail release.

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Permalink Reply by Rob Todd on October 13, 2011 at 12:40am

Well, according to philosophy, the bundle theory states that we are nothing more than our biology, environment, past experience, and memory (the reason for the distinction between past experience and memory is that memory can be false.) In short there is really no such thing a a self, unlike the woo woo soul theory.

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