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Split Brain Does Not Lead to Split Consciousness

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Re: Split Brain Does Not Lead to Split Consciousness

#41

Post by corvus_sapiens »

amelius wrote: post #7

How does a brain split operation work exactly? Do they put a barrier between the two halves? Otherwise, I would expect that signals could still propagate: cut two nerves, then push them together, and I can imagine that a signal can still pass through; if not always, then in a percentage of cases.

There are 250 million neurons in the corpus callosum, each with a diameter on the order of microns. Individually, each one transmits a very primitive signal (think biological bit) that doesn't mean much without the other millions of neurons. It's extremely complex and thus extremely frail. If the cut halves on both sides don't line up exactly, you have the equivalent of static. You wouldn't mash two cut ends of normal data cables together, and there are only on the order of 100 "neurons" there.

What you say is theoretically possible if the neurons weren't living cells and humans had the technology to reconstruct the brain's wirings. Your body isn't going to figure out which "wire" connects to which on its own.

Re: Split Brain Does Not Lead to Split Consciousness

#43

Post by Omnius »

YeGoblynQueenne wrote: post #38
insickness wrote: post #33

A few years before he died, I heard Kim Peek speak at an event. He was a savant who retained 98% of everything he read. He would memorize phone books simply by reading them once. When he read, his left eye would read the left page while his right eye would read the right page at the same time. He could tell anyone the sports scores listed in the newspaper on the day they were born. He was also severely socially impai…

My problem with that sort of demonstration of amazing memory powers is that I have no way to check the sports scores on the day I was born as quickly as the person who says they're retrieving them from memory does so. Even if I could just google them (there might be some online sports results archive or something- it would still not mean much unless I could find an identical copy of the exact listing the mnemonist me…

The outcomes of historical, national, sporting events are not subjective. It would be easy to check and verify even if you couldn't do it that second you could still after the fact check and call out anyone pretending. With or without the exact identical text the "memorizer" used.

Re: Split Brain Does Not Lead to Split Consciousness

#44

Post by aurelian15 »

throwaway26960 wrote: post #39

Does every animal/insect have two brain hemispheres? For example, what about a spider, or an octopus?

Without being an expert on the topic, I think it is safe to say that some symmetry in the nervous system is present throughout the entire animal kingdom -- just as bodies tend to be symmetric. For insects in particular, the brain is definitively split into two clearly distinguishable halves.

Octopuses in particular are a completely different story, they don't seem to possess a "central processing unit", but rather distribute necessary computations throughout their entire nervous system (it is kind of fascinating). Yet, since they have two eyes, you'll still find two symmetrical nuclei for processing visual information somewhere in the vicinity of the sensor system.

Re: Split Brain Does Not Lead to Split Consciousness

#45

Post by erroneousfunk »

YeGoblynQueenne wrote: post #38
insickness wrote: post #33

A few years before he died, I heard Kim Peek speak at an event. He was a savant who retained 98% of everything he read. He would memorize phone books simply by reading them once. When he read, his left eye would read the left page while his right eye would read the right page at the same time. He could tell anyone the sports scores listed in the newspaper on the day they were born. He was also severely socially impai…

My problem with that sort of demonstration of amazing memory powers is that I have no way to check the sports scores on the day I was born as quickly as the person who says they're retrieving them from memory does so. Even if I could just google them (there might be some online sports results archive or something- it would still not mean much unless I could find an identical copy of the exact listing the mnemonist me…

Sports scores aren't different between papers, and the order, or the specific way it was printed in the paper, doesn't matter. There are many archives where you can easily look this information up.

I was born August 9th, 1988. That's baseball season. On that day, it's a non-controversial fact that there was a double header between the Red Sox and the Brewers. The Sox lost the first game 2-3 and won the second, 5-1.

Let's assume you look up the scores on your birthdate and just ask the guy "Okay, on this date, there was a one double header -- which teams, who was home, who was away, and what were the scores?" He should be able to tell you. Doesn't matter what paper he read it in.

Re: Split Brain Does Not Lead to Split Consciousness

#46

Post by YeGoblynQueenne »

erroneousfunk wrote: post #45
YeGoblynQueenne wrote: post #38

Earlier quoted context omitted.

My problem with that sort of demonstration of amazing memory powers is that I have no way to check the sports scores on the day I was born as quickly as the person who says they're retrieving them from memory does so. Even if I could just google them (there might be some online sports results archive or something- it would still not mean much unless I could find an identical copy of the exact listing the mnemonist me…

Sports scores aren't different between papers, and the order, or the specific way it was printed in the paper, doesn't matter. There are many archives where you can easily look this information up. I was born August 9th, 1988. That's baseball season. On that day, it's a non-controversial fact that there was a double header between the Red Sox and the Brewers. The Sox lost the first game 2-3 and won the second, 5-1. L…

The point is that not all newspapers are going to be publishing the exact same amount of information on any event, including sports scores.

So, for example, if a person is saying they remember that the Red Sox lost 2-3 to the Brewers, and that they read that in The New York Times, you can check the NYT to see if they published that result on that day.

I mean, if they say they remember reading that in the NYT, but it turns out that's not where they read it, then that calls the whole "super memory" thing into question, doesn't it?

Re: Split Brain Does Not Lead to Split Consciousness

#47

Post by YeGoblynQueenne »

Omnius wrote: post #43
YeGoblynQueenne wrote: post #38

Earlier quoted context omitted.

My problem with that sort of demonstration of amazing memory powers is that I have no way to check the sports scores on the day I was born as quickly as the person who says they're retrieving them from memory does so. Even if I could just google them (there might be some online sports results archive or something- it would still not mean much unless I could find an identical copy of the exact listing the mnemonist me…

The outcomes of historical, national, sporting events are not subjective. It would be easy to check and verify even if you couldn't do it that second you could still after the fact check and call out anyone pretending. With or without the exact identical text the "memorizer" used.

OK, so how can you ever verify with any degree of certainty where and when someone acquired a memory? If I can just look up those details somewhere else, at my convenience, then how can you ever be sure I didn't?

Re: Split Brain Does Not Lead to Split Consciousness

#49

Post by umberway »

incompatible wrote: post #19

I'm not sure that this proves that there's a single consciousness. There may be a second consciousness that is receiving some information about observations from the other hemisphere.

I agree. The best that can be said is something about communication of information between different parts of the brain. But my reason is more fundamental: we don't understand what consciousness is yet. Hence we can't know what questions about 'it' are meaningful let alone what conclusions to draw.

Re: Split Brain Does Not Lead to Split Consciousness

#50

Post by taneq »

joeyo wrote: post #17
advisedwang wrote: post #2

Interestingly this work contradicts not just previous theory, but also previous experimental result. I would be interested to see if they have a critique for why the previous runs of the experiment provided a different experimental result.

They discuss a few possibilities. The first is cross-cueing, which they describe as " ... behavioural tricks, such as touching the left hand with the right hand" [1]. However, they also discuss a number of reasons why they think cross-cueing did not play a role. The second (and imho quite interesting) explanation is that the split-brain phenomenon could be transient: their subjects have had between 10 and 20 years to…

I think your second explanation is probably right. We keep discovering that brains are more adaptable than we previously thought. I wouldn't be surprised if their brains had learned to 'route around' the damage in some way over the years.
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