Week 9

This week in Behavioral Neuroscience we covered emotion. This was a really cool week because we got to talk about two of my favorite topics in all of neuroscience and psychology. Those two topics would be the most unfortunate case of Phineas Gage and a theory brought to us by Solomon and Corbit called the “Standard Pattern of Affective Dynamics.”

Let’s start with Phineas Gage. The story of Mr. Gage serves as an example of the importance of the ventromedial prefrontal cortex (vmPFC) in controlling emotional behavior. Phineas Gage was the foreman of a railway construction crew in the mid 1800s. He held this position because he was known to be level headed and in general the type of person you want to be leading your workers in their jobs. One day while on the job Phineas Gage was very seriously injured. The crew was blasting away rock to lay down the tracks which involves drilling holes into the rock and packing the whole with explosive charges to blow up the rock. Mr. Gage was packing a charge in one of these wholes with a steel rod when a spark from the rod being jammed into the whole sparked the charge and sent the pole up into his left cheek and up out the top of his head. The resulting injury was a whole clean through his head that went right through the vmPFC. Miraculously Phineas Gage survived this incident but he was never the same again. Once he had physically recovered Phineas Gage went looking for his old job again but he was unfit for duty. The man who was previously known to be level headed and reliable was now described as childish, inconsiderate of others and inconsistent in making and following through on plans with others. That is a real example of how physiological damage in the vmPFC can affect emotions.

The Standard Pattern of Affective Dynamics is my favorite theory I have ever learned because it is very applicable to basically every function of the human body. You can think of it as a homeostatic theory or mechanism. Basically the theory states that everything that happens in/to your body to move you away from the sweet spot for biological functions (homeostasis) is regulated by your body by applying the exact opposite force to whatever it is that moved you from homeostasis. In the theory the process that moves you away from homeostasis is called the “A-process” and the process applied by your body to counter the A-process is called the “B-process.” Your body will do this naturally but the more often the A-process occurs the faster the B-process will kick in after the initiation of the A-process and the B-process gets closer in magnitude to the A-process making them “cancel each other out” more completely. In lecture Eric likes to use love as the example for this and it is quite entertaining. He will tell a story about one of the students in the class. This student is minding their own business when suddenly the love of their life walks in the door to the classroom. This causes the student to experience physiological changes that go along with arousal like sweating and feeling “butterflies” in the stomach. However, because the presence of the love of this person’s life is the A-process causing this physiological arousal the feelings are gone once the love of the student’s life leaves the room. Of course, because this is the love of that student’s life they go find this person again and eventually get married. They now get used to living with the love of their life and associate many things about their life together with the person that is the love of their life as they are together so often. However, now over the years the physiological signs of arousal aren’t there anymore. This is not because the love of their life has lost their effect as the A-process but rather the B-process has become more efficient and is consistently working to counter the A-process. This brings us to the last application of the Standard Pattern of Affective Dynamics but it is rather sad. One day the love of the student’s life dies. They are gone and never coming back which means the A-process is never coming back either. However, the student’s neurology doesn’t know this so the B-process continues as it did before causing a consistent effect that is the opposite of arousal. This explains why elderly couples often die within a year or two of each other.