One
of the things I enjoyed the most from volunteering in a hospital was seeing
individuals in their recovery room after surgery. They were always in a cheery
childish mood due to the effects of anesthesia given to them before their
surgery. But how is the anesthetic able to cause this giddiness? What does this
show about consciousness in that an adult goes from being a properly mannered
individual when fully conscious to behaving in a childish way when recovering
from surgery?
Daniel
Bor discusses anesthesia in his novel The Ravenous Brain due to its
ability to help in understanding an unconscious mind that is healthy and
functional. He had surgery in the past that required him to take an anesthetic.
After the surgery he admitted that he felt like he was in a drunken state and
was even making inappropriate jokes to the nurse (81). But what does anesthesia
even do to cause this unconsciousness? Bor says that the way that anesthesia
works is that it increases the production of a neurotransmitter called gamma-amino
butyric acid (GABA), which lowers neuronal activity. An anesthesiologist then
ensures that the patient is fully unconscious by using a technique called
electroencephalography (EEG). This involves attaching various electrodes across
the scalp which detects the combined local electrical activity emitted by
neurons (88). However, sometimes this process is faulty.
Bor's discussion about anesthesia connects to an article in
the New York Times called, “What Anesthesia Can Teach Us About Consciousness”.
The article states that for every 1,000 people who undergo anesthesia, there
will be one or two people who are not as unconscious as they seem. They are
awake during the procedure but are unable to move or show signs that they have
not fully gone unconscious, resulting in traumatizing experiences. Scientists
are looking for a way to not only learn about consciousness from anesthesia,
but also for ways to improve the method of checking to see whether an
individual is fully unconscious.
To improve methods of checking the
conscious state of an individual undergoing anesthesia, neuroscientists are
searching for what they call “neural correlates of consciousness”. These are
changes in brain functions when a person is transitioning from a conscious to
unconscious state. Researchers from the University of Sao Paulo and University
of Wisconsin, Madison stimulated subjects’ brains with a magnetic field and
used EEG to trace the path the pulse took. They found that if the patient is
conscious, the electrical pulses travel all around the brain. However, if they
are unconscious, the pulse tends to stay localized and just fades away. This
means that sensory networks in the brains of unconscious people are functional,
but interbrain communication has broken down. This study shows that
unconsciousness happens when different parts of the brain cannot connect. This
suggests that anesthetics work by cutting the lines of communication to the
brain. Some scientists are suggesting creating a monitor that focuses on the
brain’s ability to communicate with itself, so seeing the connections the brain
makes and not just the overall electrical activity. Activity in conscious
brains shows “recurrent processing” which are signals are sent from the sensory
area to the processing area and back again. Therefore, doctors are able to see
if a person is unconscious if these recurrent processes are not showing in the
brain.
Anesthesia has allowed for numerous
discoveries into the unconscious individual. It helps explain why the patients
I saw in the recovery room behave in a childlike manner. The anesthesia caused
blockage of many signal connections throughout the brain, so when the patient
is recovering, the signals are slowly reconnecting. Perhaps the patients behave
in a childlike manner because the signals throughout their brains in the
recovery stage are not as fully connected as when they are conscious. Whatever
the cause, scientists and Bor have been able to gain great insight into the
brain and consciousness thanks to the workings of general anesthesia.
Bor, Daniel. The Ravenous
Brain: How the New Science of Consciousness Explains Our Insatiable Search for
Meaning. New York: Basic, 2012. Print.
Koerth-baker, Maggie. “What Anesthesia Can Teach Us About
Consciousness.” The New York Times. The New
York Times, 14 Dec. 2013. Web. 16 Oct. 2014.
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