A tricky question

[Aanker]

(This may be more of a philosophical question, but I really wanted to ensure that this was kept in a forum where discussion would primarily take place based on the natural sciences and have as little involvement from religion as possible)

Allow me to make the presumption that the consciousness (with this I mean self-awareness, the "self", in case the terminology is wobbly) of, say, a person would be divisible: that we would be able to split the brain of a person into two autonomous halves that each could operate independently of each other. Note that I am not referring to the actual anatomical halves of the brain, but rather a supposed surgery in which the literal consciousness of a person is split in two. We know that consciousness is related to the brain (some animals have self-awareness, most do not, depending on their brain to body size proportion and functionality; elephants, apes, magpies and dolphins are commonly cited examples), so it would seem reasonable to assume that it either constitutes a specific area or several areas.

The question is what would happen to the original person? Would he or she assume one of the two resulting consciousnesses (through chance - and in that case - why and how would chance determine this?) or would the original self-awareness "die", only for two similar self-awarenesses to arise with the same memories (or respective halves of the original memory) as the subject before the "surgery" - and in that case, why? We can more or less safely say that it is impossible for the person to assume both self-awarenesses (assuming there is no communicability between the two, which there is not, without axons spanning between the involved neurons).

It would seem that, depending on the answer, we acquire different implications. One example would be that, if the "pre-surgery" consciousness ceases to exist, there must be some form of "absolute barriers", e.g. without these properties or functions, self-awareness dies. If that is the case, what are the barriers, and why are they absolute? On the other hand, a result in which the original person assumes one of the two "post-surgery" consciousnesses implies that self-awareness is flexible, but it raises more questions in the line of how or why?

The question itself may be paradoxical. For there to be an answer, we must have a definite result, but since the definite result is impossible to acquire without consulting or being the test subject (each related to unique problemacies) we may very well find ourselves in a situation where we ask the same question again (is the answer from the original self-awareness?/did I die?). The original supposition may be an impossibility - then again, we must ask ourselves why - and, indeed, from a practical perspective we see that there may be no use in asking these questions since the observability of the results is limited or inexistant.

[The Hedge Knight]

I really don't think anyone can conclusively answer this. Conciousness as a state is still undefined and I think adding the extra level of difficulty of one vessel (human) going from one occupant to two. Having said that multiple/dissassociative personality disorder (DID) is a real condition though poorly understood to the point where there is no general consensus on diagnosis or treatment, as I believe is most of neuroscience. Sadly it seems the main source of understanding of the workings of the brain stems from when parts of it cease to function and the result is observed. Back on the subject of DID generally the condition involves prolonged periods of amnesia as the second personality takes over in my mind giving evidence to the idea that the personalities are clearly separate, its also worth noting cases in which the alternate personality has different traits such as handwriting demonstrating the degree of separation between the alternate and the "first" personality. Its also interesting that the condition is seen as trauma related and generally emerges at a young age implying new personalities are somehow created yet that the original personality remains. This may well interest you as she describes the creation of multiple personalities within herself yet clearly still considers herself to be the original.

[Morkonan]

...The question is what would happen to the original person? Would he or she assume one of the two resulting consciousnesses (through chance - and in that case - why and how would chance determine this?) or would the original self-awareness "die", only for two similar self-awarenesses to arise with the same memories (or respective halves of the original memory) as the subject before the "surgery" - and in that case, why? We can more or less safely say that it is impossible for the person to assume both self-awarenesses (assuming there is no communicability between the two, which there is not, without axons spanning between the involved neurons)....

Well, let me preface my response with the acknowledgement that there have been several, quite notable, cases where the corpus colossum has been severed or damaged and this resulted in clear behavior changes. Lesions to the brain have also produced dramatic behavior and even what appear to be changes in a person's sense of morality, something most would say lies at the core of who we are. There are quite a few case-studies on both effects. Also, IIRC, "Ghost Limb" (Not "Phantom Limb"), cases where lesions or abnormalities in the brain end up resulting in a person who has a limb that appears to be being controlled by "someone else" have also occurred. These patients could have an arm/hand that would appear to do things on its own, such as attempt to :wub: or even assault the patient themselves... all outside of the patient's voluntary control. A very frightening thing and one that points to some very strange questions about "consciousnesses" and this idea that we are an "individual" one...

Now, what would happen in your theoretical question, given the rules that you have outlined? Well, "consciousness" is a trait. Your patient has retained that. You mention no loss of memory, no differences, except physiological, in the two "consciousnesses" within the patient. I can only imagine that the patient continues to survive. In which consciousnesses? In both, however at the moment of voluntary behavior and individual experience, they would diverge as individual consciousnesses. In effect, they would be clones of one consciousness. (Note: ONLY given the rules that you have laid out. There is nothing in "reality" to create the effects that you describe.)

That a person's personality changes does not mean that that person no longer exists. The new behaviors are simply incorporated into a new schema. We are a collection of memories and conditioned behaviors that are floating in a chemical soup that is constantly changing, itself. A new experience does not create a new person.

It's interesting to note that there was a time when the bilateral symmetry of our brain was thought to heavily contribute to "consciousness" as a result of the interplay between two, almost complete, individual consciousnesses within our brain. Other strange things relating to this issue are the questions surrounding such things as "muscle memory" and "active subconscious direction", like when you drive your car to work, but have no recollection of actually making any decisions during your driving experience, like when to turn, when to stop for a red light, which roads to take, avoiding traffic problems and planning around obstacles, etc... These are all amazing, very complex behaviors and thought processes, but many people never seem to take an active role in directing those physical actions. What's going on, here? Could it be that the interplay between things like muscle memory and the systems that help take over mundane tasks are working with some sort of higher center in our brain to develop "consciousness?"

Love it or hate it, there's also a possibility that allows for a quantum consciousness, explained in "The Emperor's New Mind" by Roger Penrose. Controversial to be sure, but it must be considered.