When you talk about yourself do you really know what you mean? Some people say, “That’s just who I am!” but do they actually understand themselves? These are very important questions and oddly answerable for a neuroscientist.
The self is not a large whole but rather, fragments (or memories) of our past experiences. The self is the most deeply ingrained knowledge we have, which is shown in Alzheimer’s patients. Often they will forget where they are and forget autobiographical information but continue to answer at the call of their names.
Dr. Nelson concedes that there is no good definition for the self in terms of what we know now within neuroscience. He wants to draw a very clear line between the self and consciousness. They are related but they are not the same and therefore we cannot use these terms interchangeably. However, we can use “me” or “I” to refer to the self because these are the terms we use referring to our selves. Studies have shown that other animals besides humans have a sense of self. This group includes primates (obviously), elephants and dolphins. The greatest difference between the human sense of self and other intelligent animals’ is the way we express our selves.
Humans have developed a very specific language to communicate with one another about ideas and experiences. Other animals use communication for different things like warnings, finding another’s location, etc. Foolishly humans think other animals understand our language so we talk to them as if they know our intentions. Humans are by far the most arrogant of the animal world. Other animals also use body language way more than humans do because of the specific language we have. We have made body language almost unnecessary. The animal world revolves around survival. Humans are far beyond that in everyday life (usually) and have been for thousands of years. The focus turned from survival to metaphysical subjects (beyond and outside of ourselves). I like to call this the evolution of mind.
Something that can really shake a person’s sense of self is if they suddenly don’t recognize a part of their body as their own. Wouldn’t that be weird? Some people actually develop this problem!
Suddenly (after a stroke in the right parietal lobe of the brain which is dominant for identifying one’s self in the world) their arm is unrecognizable to them, although they accept that it is there. They understand how crazy it sounds that they don’t know this particular limb, but their brains are unable to accept it as a part of themselves. Past memories of this arm seem to be gone but it is actually the retrieval of these memories that has been shut off (due to the parietal lobe stroke).
Dr. Nelson refers to an interesting phenomenon called the phantom limb syndrome. When someone loses a limb sometimes the patient feels as though the limb is still there and functions just as it normally would. Sometimes, the limb is stuck in an uncomfortable position or it causes pain to its owner.
Why would someone think that their limb is there when they can look down and see that it is clearly not there? The answer is: the part of their brain that controlled that limb or offered sensation and perception to its owner is still there. It doesn’t leave with the limb so sometimes activation of nerves close by will cause feeling to the owner. This phenomenon can be very confusing, although it doesn’t last forever. Eventually, the brain will allocate some other function along the same general lines to the part of the brain that previously controlled the limb (because the brain is freaking cool like that!). Dr. Nelson relates a case study in which a few neuroscientists felt as though they should help to relieve the situation for one particular patient.
A group of neuroscientists were collaborating on one patient’s problem (as they often do because multiple minds are better than one) with a phantom arm that was in an uncomfortable position and was causing him much distress. The neuroscientists developed a contraption that showed a rubber arm where his arm would have been. By having him observe the arm being stimulated over and over again with a feather for a few weeks, he was forever relieved of his phantom limb. His brain registered the stimulation of the arm so that he literally (specifically his brain) felt the sensation in his phantom arm. The contraption quickly aided his brain in pruning (neuro term I always liked) back those neuro-connections that had still been there. This shows that the brain is able to rearrange the self rather fluidly.
Some people believe they have sprouted another invisible or “spare” limb. This is due to a stroke in the brainstem. The spare limb in the case study Dr. Nelson refers to was hostile toward its owner and would try to strangle her. Sometimes this patient would sprout another leg. It is not completely understood how the brain makes this happen but these sensations didn’t last forever. They went away as she recovered from her stroke. The question these examples bring up is: “are the revelatory changes in one’s sense of self during spiritual experiences just kindred illusions?” Dr. Nelson’s opinion is clear on the matter because he states, “If the self could be thought of as a figment of our imaginations, could the same be said of spiritual truth?”(Dr. Nelson).
Another important point in our search is that the frontal lobes of our brains house our personalities. Changes to the prefrontal lobes (whether injury or disease) can cause changes in an individual’s personality. The most famous case of this was a railroad man who was shot through the frontal lobes with a metal rod in a work-related accident. He was known, previously, as a kind, generous and generally happy person but after the accident he became rude and tactless.
The brain is so fascinating because two halves (or hemispheres) form its whole and the mirror images communicate through a dense band of nerve fibers (corpus callosum) near the brain’s center. If the fibers are severed (generally this is done to relieve grand mal seizures) the two hemispheres can still communicate to a degree. However, there is a very clear dispute between the two sides. Interestingly, case studies have shown that often either arm of the subject will do the opposite of the one on task. For example, one patient was observed pulling his pants up with one arm and pulling them down with the other. Dr. Nelson suggests perhaps there may be more than one conscious self with a single brain and begs the religious yet scientifically charged question “Might one side of the brain feel itself blessed while the other thought it was damned?” You could say that’s true.
Sometimes severing the corpus callosum would not relieve a patient of seizures (depending on the location and severity) but removing a portion of the brain would. What happens in this situation is a neuropsychologist investigates what part of the brain to remove. This is done by anesthetizing portions of the brain previous to surgery (totally painless due to the lack of pain sensing neurons [yes, they’re different and for more info, just ask ;-)] directly on the brain’s surface). Then the neuropsychologist asks the patient questions to determine what parts are awake. Often, the patient will exhibit drastically different personality traits as well as when the prefrontal cortex of the brain is injured.
Dr. Nelson states, “It (each hemisphere) may also have its own ideas and experiences of spiritual insight or truth, different thoughts and feelings about the holy and the divine.”
Dr. Nelson deems it important to point out that evolution led to the development of two hemispheres within the vertebrate brain (that’s us). Nature would not separate the brain hemispheres if it weren’t meant for each side to do something a little different than the other (or specialize). We all call ourselves “left brain” or “right brain” people due to what we are naturally proficient in doing. The left hemisphere is good at organization and problem solving with the right focuses on tasks and experiences. The right brain is interested in accuracy of an event and the raw data while the left is interested in making connections or a story about the occurrences.
Dr. Nelson makes a surprising statement in my opinion when he asserts, “It is tempting to speculate that as primates develop their interpretive, language-rich left hemisphere, they began interpreting their observations of nature in a supernatural context. It could be that the left brain first brought us our gods; it certainly allowed us to talk about them.”
How does a person think without language? People can be born without hearing, and before today’s advances, would never hear their whole lives. Some of these people are also born blind like Helen Keller. People couldn’t believe that people like her (before she came along) were people at all because they had no way of communicating (until Anne Sullivan came along). How surprised was everyone when she became an author after discovering the English language? “Does language make the self or does language only make the self detectable? Considerable evidence tells us that the right hemisphere can, on its own, be a human self without language.” The answer: The same way you think with language. Language gives us a common understanding of what we think.
Cotard’s syndrome is named after the doctor who uncovered the first well known case study. The result is that the patient thinks they are dead, although they are perfectly fine and completely rational (besides the obvious). They will often think they are decomposing or walking around in the afterlife. It is very difficult to study something that occurs so infrequently so there is little known about the part of the brain that would cause this malfunction. Dr. Nelson says that when it is found it will be the part that affirms our existence. He states, “The power our brain has over our most important assumptions is awesome. We need to keep this firmly in mind as we examine spiritual experiences such as the mystical and near-death.”
Join me for the next section and chapter four, “The Varieties of Near-Death Experience”.
Wow! What an awesome post! I don't think I've ever experienced something as enriching as what I just read.
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