The problem with keeping a brain in a synthetic environment goes well beyond providing a electrical interface and nutrients. Your brain is tightly coupled with the rest of your body through other means, such as hormones, and complex chemical feedback loops from various organs. Basically one must cater for all the variables for a brain to survive in the long term.
Even if we manage to get a good electrical interface happening, the brain needs to relearn, or reconfigure its neural networks to work with the new interface. Basically it needs to rewire and undo what it learnt during the first crucial 5 years during childhood... which is incredibly difficult for an adult brain. For instance, you don't see automatically, you learn to see very early on. Therefore, if the optic nerve was cut and wired to something else, the brain may not able to interpret the visual signals as something meaningful, even though the nerve was stimulated properly. The subject may experience flashes of light, but probably not perceive recognisable shapes.
That said, the brain can be remarkably adaptable, so who know how far we can go. Impossible? No. Hard? You bet.
The idea is that the "vat" and the associated hardware would precisely imitate the exo-brain environment. This means that it would send the EXACT same neural impulses to the exact same neural pathways as the body's original hardwiring would, and thus there would be no relearning necessary. I fully understand that this is medically infeasible because of the complexities of the connections and the fact that every person's connections would be different... but that's the idea.
I saw this on Nova, but I think this is the same as the thing I saw. The organ still dies eventually.
I think the largest problem is that, while we can get organs to last a lot longer, there are so many complex things that go on in the human body that are all controlled by different organs and affect every other organ. So to make a good environment for an organ, you have to simulate the inputs from all the other organs and simulate all the organs' effects on all the other organs.
In the case of the brain I feel like there would be tremendous potential to cause HUGE amounts of pain. Imagine if every nerve in your body suddenly sent max pain signals to your brain.
The idea is that the "vat" and the associated hardware would precisely imitate the exo-brain environment. This means that it would send the EXACT same neural impulses to the exact same neural pathways as the body's original hardwiring would, and thus there would be no relearning necessary. I fully understand that this is medically infeasible because of the complexities of the connections and the fact that every person's connections would be different... but that's the idea.
I don't care about making an exact duplicate of the connections. The idea is actually more aimed at something like a robo cop and it could use a child's brain so that it can easily rewire it's self to the interface. Why build artificial intelligence when we have over 6 billion brains ready to be harvested?!
Wasn't there something a few years ago about rat brain cells being used to control a flight simulator? I remember something about pureed rat brains in a Petri dish growing connections with electrical contacts to fly an F-22.
So, I think the answer is that while we have the technology to connect biological neural nets to electronics, we are still very far from connecting an intact brain to a system.
Old Username: Talroth
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[quote name='KanonBaum' timestamp='1303714752' post='4802568']
Obvious solution is obvious:
Humans are remarkably well-adapted to living in the real world. I think that anything that fails to successfully emulate the level of complexity that we experience in our everyday lives will not be sustainable
[/quote]
There are people that play WoW for multiple hours only stopping to sleep and eat. Imagine the efficiency one could attain without organic restrictions. Probably would still need to sleep.
Anyway I think transferring a human's consciousness into a computer is more realistic. In 2030 we'll have computers that can simulate all the neurons and connections in the human body. Hopefully by that time biology will have caught up and actually understand all the connections and technology will be able to do a real scan of every neuron to duplicate the state into a computer. Kind of odd making a copy though. Like the Stargate effect.
Is it even a person then if it's all simulated on a computer? How can it be when you could clone it 100 times and get identical results. I personally would prefer to be a brain in a vat than "have my consciousness transferred".
When I think of a neural network I can see it learning anything with enough neurons, time, and information. I can see teaching a neural network to play a video game since all that would be required is positive feedback when the neural network completes a task in time and negative feedback when it fails to complete the task but how exactly do human babies learn?
When you think about how little effort babies need to exert to get food or other needs and as a result gratification. It makes me wonder how they progress any further?
As much fun as it sounds, cutting out one's brain is neuro-anatomically a really stupid idea, regardless of whether you believe that you have a suitable oxygen carrier and such.
The axons of all periperal nerves go a long way into the spinal cord and are switched only in the segment where the respective nerve leaves the spinal canal. Which means that no matter where you cut, you'll severe the axons and kill the respective cells inside the brain. The cells having synaptic connections with these will secondarily degenerate. A nerve is not just a copper wire that you can pull out of the wall any way you like, it's part of a living cell. You can't glue another axon onto it, and you can't do a fresh wiring. You cut it off, the cell dies, it is really that simple.
Think about why it takes months for people with a severed peripheral nerve to regenerate (if at all!). That's because if you are so lucky as to being able to move a limb again after months, it's because a new axon from a reserve cell has grown from the anterior horn all the way down to the muscle (along the empty neurilemma). If the axon could actually heal, it would only take a day, and the chance of success would be 95% rather than 5%.
Also, [s]the ability to destroy a planet is insignificant[/s] the ability to carry a lot of oxygen is insignificant next to a well-balanced system. Indeed, since oxygen is a radical and brain tissue has a highly active metabolism coupled with a very very limited regenerative ability, a high yield oxygen carrier is not a good thing at all. This may help in certain emergency situations where oxygen is scarce and thus every additional bit is welcome, but as a general long-term treatment, this is surely not an advisable. There would have to be a suitably buffered solution too, because the brain is even more sensible to changes in pH (and not only that!) than most other organs.
And then of course, among a dozen other serious issues in keeping a brain alive, sterility would need to be assessed. Antibiotics, oh joy. We can't even save every life with antibiotics today if a considerably less important and less sensitive part than the brain is affected. Thousands of people worldwide die from peritonitis (or, insert a dozen other things) every day, in countries where antibiotics are readily available.
It is futile to even discuss a brain-world interface. Some of the best scientists were so far just about able to develop more or less functional nerve-artificial-hand interfaces and more or less functional cochlea replacements (which are better than nothing, but nowhere near the real thing).
And then of course, among a dozen other serious issues in keeping a brain alive, sterility would need to be assessed. Antibiotics, oh joy. We can't even save every life with antibiotics today if a considerably less important and less sensitive part than the brain is affected. Thousands of people worldwide die from peritonitis (or, insert a dozen other things) every day, in countries where antibiotics are readily available.
So you're saying all that neosporin I just ate... dammit! My life is a lie!
