Thursday, October 16, 2014

How Unconscious Are You?

          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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