The Networks Behind Human Decision Making
When a person is picking where they want to take a vacation, what color suit will look best for an interview, or whether they will go to the gym or not, there is a complex set of thinking that goes along with each decision. In the article “Making Choices: How Your Brain Decides”, Maia Szalavitz talks about two networks in the nervous system which together influence what decisions a person makes. She calls the first network the evaluation side which determines the potential risks and rewards of a given situation. The other network is called the cognitive control side which guides behavior and keeps the evaluation network on track. In practice, a person is faced with an alternative and the evaluation side chooses an outcome. This network may then start to stray and pick something which may have a lot of reward but also at a great risk. The cognitive control network will then step in and help to return the evaluation network to a more moderate deduction. Together the two networks help human beings make rational life decisions.
When these two networks are functioning properly, the mind is stable and the system can be viewed as a structurally balanced graph. Each network consists of many neural pathways that send signals from the brain throughout the body and back. Being that the two sides function independently, there must be a positive relationship among all the neurons (nodes) in each particular network. However, since one network acts as a check against the other, the connection between the two sides can be thought of as a negative relationship. This clearly illustrates a balanced graph as all triangles will have either all positive edges or two negative and one positive one.
The importance of having a balanced network in the nervous system can be shown by analyzing the case in which the network becomes unbalanced. If positive connections begin to emerge between the two sides, the cognitive control portion may no longer have a say in the evaluation side as it will just agree with all payoffs put forth. This will disable a person from seeing the true value in their decisions. The article points out the case of depression emerging from this dysfunctional network. In this case, a person cannot get any enjoyment out of the decisions they make without the help of their control side because every option looks the same, dull and dreary. The system needs both sides to function on their own in order for humans to function properly.
From this example, we see that structurally balanced graphs as derived from social networks also appear in our biological functions.
Source:
http://healthland.time.com/2012/09/04/making-choices-how-your-brain-decides/