The Limbic system is a part of the brain’s reward center. The limbic system includes the amygdala, hippocampus, hypothalamus, septum pellucidum and other structures. These are all parts of the brain involved with emotions such as fear or pleasure. They play a role in regulating moods and behaviors like motivation and decision making.
In addition to these emotional centers, there is another part of the brain called the orbitofrontal cortex which plays a major role in decision making. When it comes to decisions, this area tends to favor immediate rewards over delayed ones. For example, if you are deciding whether or not to go out tonight or buy some new clothes, your choice will probably be based on what you think others might want right now rather than what they may want later.
It is also possible that your decision will depend on how much money you have available. If you have $20,000 and the opportunity cost of going out tonight is only $5, then you would probably prefer to spend the extra $5 on something else instead of spending it on a night out. You are likely to make different choices depending upon your own personal values and preferences.
So what does all this mean?
It simply means that your limbic system’s role in fear and reward can lead to choices that are irrational when compared to a fully rational person. These irrational choices can arise from factors such as the desire for pleasure or a dislike of immediate pain.
Research involving monkeys has shown that the orbitofrontal cortex might be involved in rule acquisition and modification. It is possible that this part of the brain may not be fully developed until a later age. This part of the brain interacts strongly with the amygdala, which is heavily involved in emotional experiences such as fear.
If part of this system develops later than others, then it might explain impulsive choices that seem to arise from emotional feelings rather than rational thinking.
For many people, the thought of snakes, spiders, or rats can cause a feeling of fear. Most people experience this at some point in their lives. Most people also have a natural aversion to poison.
While some people have this aversion to a greater degree, almost everyone will exhibit some signs if poison is ingested.
The limbic system can lead to the fear of things that pose no real danger or to a dislike of things that might actually be useful. A good way to think about this is by imagining yourself as a child. As a child, you probably were not capable of distinguishing between real and imaginary fears.
You simply reacted to things as you saw fit. Most of the fears that develop in childhood are due to conditioning by parents and society.
As a child, your limbic system allowed you to feel a fear of something without any real threat being present. As an adult, you will tend to be better able to distinguish between real and imaginary fears due to the operation of your prefrontal cortex. Your limbic system, however, is still going to be prone to the same irrational fears that it always has been.
In reality, you probably do not need to fear snakes, spiders, or rats. In reality, you probably should not fear poison. While this is true for most people, there are some people who suffer from specific phobias.
These people experience extreme fear in these situations and will go to almost any length to avoid them.
- The limbic system (visceral brain) and emotional behavior (PD MacLean – AMA Archives of Neurology & Psychiatry, 1955 – jamanetwork.com)
- Synchrony between limbic system theta activity and rhythmical behavior in rats. (BR Komisaruk – Journal of comparative and physiological …, 1970 – psycnet.apa.org)
- Limbic system fos expression associated with paternal behavior (B Kirkpatrick, JW Kim, TR Insel – Brain research, 1994 – Elsevier)
- The two-arousal hypothesis: reticular formation and limbic system. (A Routtenberg – Psychological review, 1968 – psycnet.apa.org)