Nature of the brain

I've been thinking a lot about the brain, lately.

Neuroscience, as far as I understand, has shown that the brain has specialized areas for motor control, sensory control, language, memory, and on and on. People who have strokes or incur brain damage in those areas will suffer degradation or loss of those abilities.

How, then, is someone like this able to function?

uk.reuters.com...

WASHINGTON (Reuters) - A man with an unusually tiny brain managed to live an entirely normal life despite his condition, caused by a fluid buildup in his skull, French researchers reported on Thursday.
Scans of the 44-year-old man's brain showed that a huge fluid-filled chamber called a ventricle took up most of the room in his skull, leaving little more than a thin sheet of actual brain tissue.
"He was a married father of two children, and worked as a civil servant," Dr. Lionel Feuillet and colleagues at the Universite de la Mediterranee in Marseille wrote in a letter to the Lancet medical journal.”

Link contains the full article, with MRI photos.

This man had a diminished IQ, but I've heard of an older case involving a girl in the late 1980s or early 1990s (I think) who was excelling in school.

I realize the article suggests his normal functioning is due to other parts of the brain “picking up the slack,” which makes sense. But it makes me wonder why large brains are necessary if people can (occassionally, at least) live apparently normal lives with such sparse brains.

Another example of tiny brains doing amazing things can be found in honey bees. Honey bees communicate to the rest of the hive that they've found a food source, as most people are aware. People may be less aware that they also communicate the distance to and direction of the food source. They communicate the direction to the food source relative to the position of the sun. They will also compensate for the change in the sun's position when communicating the direction to the rest of the hive. So, a foraging honey bee has to remember where the food it found was located, remember the distance it travelled from the food source to the hive, remember the position of the sun when it found the food source and compensate if the position of the sun has changed when communicating to the rest of the hive. Seems pretty complicated for a tiny brain, which would also need to be processing visual information, coordinating flight, dealing with and coordinating various internal processes etc.

I guess I'm wondering how important is the structure/volume of the human brain in how we think, what we remember, how our bodies work, etc? To me the two examples above suggest that maybe we need to be looking at the brain in a different light. However, I'm certainly not a neuroscientist; there could be a lot of information I'm missing that, if I knew, would not have led me to believe these examples cast doubt on our current understanding of the brain.

Does anyone have any thoughts on this? Any enlightening information?

reply to post by SlightlyAmazing

Excellent post.

Hydrocephalus is a fairly common birth defect, affecting 1 out of 500 births. It is more common than Down syndrome. It is caused by a build-up of cerebral fluids in the brain, which slowly destroys the brain and kills the infant.

Before 1960, this horrible birth defect was nearly always fatal. But in 1960 a medical procedure was created where a plastic shunt is placed in the cranium, draining the spinal fluid into the abdomen. Now, almost all cases of hydrocephalus are easily and routinely handled, and hydrocephalus is completely cured in 95% of the cases.

en.wikipedia.org...

Here is what is amazing: in 1960 there were thousands of babies who had advanced hydrocephalus, and were lucky to be born at the exact time that this cure was found. Countless numbers of these children fully recovered, and led normal lives.

In later years, with the advent of CT Scans, medical doctors were interested in learning what damage, if any, had occurred due to this advanced (and now cured) hydrocephalus. Had the brain somehow recovered?

No. In many case, it was clear from the CT Scans, that these children (now adults) had suffered extreme brain damage. In a few cases, these completely normal people had no real brain at all, and their skulls were simply empty voids, with a thin line of cerebral tissue, and the rest filled with spinal fluid.

It is an amazing story. I saw this documented on the Discovery channel a few years ago. They interviewed these young adults. They were obviously normal. One was a chess grandmaster.

#

So what is the conclusion?

Obviously, the conscious mind does not exist in the cerebrum or the main part of the brain. It probably exists in the "brain stem", also called the "reptilian brain", which is the oldest part of the brain, and the part that connects the other portions of the brain to the spinal column. That is just a guess, but it makes sense to me (as much sense as anything else I've heard, anyway.)

Originally posted by Buck Division
reply to post by SlightlyAmazing

 

In later years, with the advent of CT Scans, medical doctors were interested in learning what damage, if any, had occurred due to this advanced (and now cured) hydrocephalus. Had the brain somehow recovered?

No. In many case, it was clear from the CT Scans, that these children (now adults) had suffered extreme brain damage. In a few cases, these completely normal people had no real brain at all, and their skulls were simply empty voids, with a thin line of cerebral tissue, and the rest filled with spinal fluid.

It is an amazing story. I saw this documented on the Discovery channel a few years ago. They interviewed these young adults. They were obviously normal. One was a chess grandmaster.

I had no idea it had happened to more than a few people. To me that suggests even more strongly that models of the brain should be reconsidered. There are always exceptions, but in this case it seems living a normal life was the rule, not the exception.

Do you remember what this documentary said the reason for their completely normal lives was? Or were they just saying "neural plasticity, nothing to see here, forget the massive loss of brain tissue" ?

Originally posted by Buck Division
So what is the conclusion?

Obviously, the conscious mind does not exist in the cerebrum or the main part of the brain. It probably exists in the "brain stem", also called the "reptilian brain", which is the oldest part of the brain, and the part that connects the other portions of the brain to the spinal column. That is just a guess, but it makes sense to me (as much sense as anything else I've heard, anyway.)

That might be the common area in all these cases. If the conscious mind is located in the brain stem, though, could that also mean most/all animal life is capable of the same sort of learning/reasoning/planning that humans are?

I'm pretty sure I remember a case where the cranium was for the most part fluid filled, the brain tissue was found to be spread throughout the patients body, occupying space between the other organs.

We are indeed an amazing piece of engineering