Is a split brain consistent with a soul?

[granpa]

Exactly. And there is lots of evidence for that. We don't even have to get to so-called pathological states like "multiple personality" for that. Memory of every healthy person is context dependent. People behave differently at work from when they're at home without realizing it. And this is only the temporal aspect of being split. Even when we're talking to someone we may look at things/sensations from different angles and if this happens unconsciously it can appear like different personalities almost fighting against each other. I'd even say that this is the normal state of affairs.

So one should rather ask, from where comes the illusion of a preferred personality called "ego" ?

i tend to think of the self as having three parts.

consciousness-the part we think (fuzzy logic) is our self.
ego-the part we subjectively feel (inductive/abductive thinking) is our self.
spirit-the part we know (deductive reasoning) is our self.

http://en.wikipedia.org/wiki/Abductive_reasoning

 

[OOO]

i tend to think of the self as having three parts.

consciousness-the part we think (fuzzy logic) is our self.
ego-the part we subjectively feel (inductive/abductive thinking) is our self.
spirit-the part we know (deductive reasoning) is our self.

http://en.wikipedia.org/wiki/Abductive_reasoning

Yeah, three sounds good.

 

[twanster]

I have read about some of the split brain experiments in which the split brain subject wears a specially designed lens which only allows light to contact one half of each retina. This means each eye now only sends info to one side of the brain. This allowed experimenter to show images to both sides if the brain and test recall of the images. They found that the subjects could only verbally recall what the dominate hemi(almost always the left hemisphere) was presented with. But when asked to reach each hand into a box without looking and pull out the object that they saw with each hand(remember each hemi control one side of body), they pulled two different object out of the box and they were both correct even though the person could only recall seeing one image out of one eye. This means the person is only aware of the dominate consciousness but the question still remains if the other hemisphere has a separate consciousness and if so, does it have another soul or the just the other half of the original. At first this lead me to believe that the soul must reside in the dominate hemisphere and the opposite hemi is like extra RAM for other mental processes but after learning more about it this doesn't seem to be the case. The language centers are normally in the left hemi so it appears that this is the only consciousness because it can verbalize but it is likely that the right hemi is just a conscious but happens to not hold the language centers.

 

[Ferris_bg]

Both the two hemispheres are conscious, but only the left can talk.

Similar dissociation is found in the so-called split-brain patient, in whom the cerebral hemispheres have been separated (by surgically sectioning the corpus callosum and anterior commissure) in order to control chronic epileptic seizures. Split-brain patients seem to have two independent conscious selves. Because the non-dominant (usually right) hemisphere is "mute", some might assume that only the dominant (left) hemisphere, which "talks", is conscious. However, as we shall see next, by forcing behavioral choices that rely upon information available only to the right hemisphere, it is possible to identify a broad range of cognitive functions that are mediated by the right hemisphere alone.

When a split-brain subject was presented with an apple in the right visual field and questioned about what he saw, he said — not surprisingly — apple. When however, the apple was presented to the left visual field, the patient denied having seen anything or, if prompted to give an answer, guessed or confabulated. This failure is not because the right hemisphere is blind or is unable to remember a simple stimulus. The patient could readily identify the object with the left hand if he could point to it and, using tactile cues, could pick it out from several others presented under a cover. Thus, when visual stimuli were limited to the right hemisphere, the patient could not name what he saw but was able to identify it by nonverbal means. This anomia suggests that although the right hemisphere cannot talk, it indeed can perceive, learn, remember, and issue commands for motor tasks.

We first demonstrated the left hemisphere’s unique drive to interpret the world around it using the simultaneous concept test on a split-brain patient [61] . Patient P.S. was shown simultaneously a chicken claw to the speaking left hemisphere and a snow scene to the silent right hemisphere. Patient P.S. was then instructed to pick out the picture most related to the scene he just saw from a set of eight choices, using both hands. His left hand (controlled by his right hemisphere) chose a snow shovel, while his right hand chose a chicken. When asked why he chose those particular pictures, P.S. replied, ‘ Oh, that’s simple. The chicken claw goes with the chicken, and you need a shovel to clean out the chicken shed ’ . While the speaking left hemisphere can easily explain that he chose the chicken with his right hand because it was picture most related to the chicken claw that he saw, the speaking left hemisphere did not see the snow scene so it must concoct a rational and reasonable explanation for why his left hand chose the snow shovel as well.

As demonstrated in the simultaneous concept test above, the left hemisphere quickly interprets the actions of its left hand controlled by the disconnected right hemisphere in a way that makes sense for the patient. It has no internal representation available to explain why he is moving his left hand in that way. Yet, to the patient, the movement seems perfectly plausible once its actions have been interpreted. Interestingly, this does not always happen instantly for the patient. Sometimes it takes the patient’s left hemisphere as long to figure out what its left hand is doing as it would an outside observer. For example, in one session we presented the word phone to the right hemisphere of patient J.W. and asked him to verbalize what he saw. Of course, J.W. was speaking from his left hemisphere and his left hemisphere did not see the word ‘ phone ’ , and his right hemisphere was mute. Therefore, he said he did not see anything. However, when we put a pen in his left hand and asked him to draw it, J.W. immediately started drawing a phone. For the outside observers who did not see the word ‘ phone ’ displayed, it took some time to make out what J.W. was drawing. J.W.’s left hemisphere was in the same boat. Fortunately for us, J.W. tends to articulate what he is thinking (a great trait for a research subject). He was quite confused by what he was drawing, and started making guesses about what he saw. It was not until the picture was almost complete that outside observers, including J.W.’s left hemisphere got what his left hand was drawing. At which point, J.W. exclaimed, ‘ Duh, it’s a phone ’ . The communication between the hemispheres happened out on the paper and not within his head. In the meantime, his interpreter struggled to find an explanation for his actions. Usually, the interpreter’s explanations come much more readily. For example, if we flash the command ‘ stand up ’ to J.W.’s right hemisphere, he will stand up. But if we ask him why he is standing up, he doesn’t respond, ‘ well, you just told me to ’ because that command is not available to his left hemisphere. Instead, J.W. will say something like, ‘ I just felt like getting a coke ’ . His left hemisphere is compelled to concoct a story that provides an explanation, or interpretation, of his actions after they have already occurred.

 

[twanster]

In this kind of experiment does the right brain have access to memories? can it actually think or can it only respond to simple stimuli? Humans think using language so is the right brain even capable of rational thought or is it just composed of separate cognitive functions that in a normal brain only supplement the left side. This discussion is about the soul and where it is and can it be split. I can say the words " I am me" in my head and I know that is coming from my left hemi. does this mean that this is where the soul lies or just simply where my language centers lie? My point is you obviously don't need your entire brain to have consciousness or what we call a soul but just because the disconnected right hemi can perform tasks doesn't necessarily mean it has what we call a soul.

 

[Pythagorean]

Personally, I think the more we understand the brain, the less purpose their is for a soul. The functions of the brain can probably explain it all.