| Published in : Article Written by Arantxa Txintxurreta on 2008-02-28 05:49 |
 Imagine a house on two floors plus an attic above and a basement below. At first, only the basement was built; that is why it is the oldest room in the house. As time went by floors were added. On the ground floor there is only one room, large and elegant even if it is rather old. There is a wide staircase to go up to the first floor and at the top of the stairs there are two rooms, one on the right and one on the left. It is easy to go from one room to the other, as they are separated by only a couple of metres. And a little further up is an attic, the most modern part of the house. It looks like a maze and is very mysterious. Apart from the large staircase, there are many other flights of stairs to go anywhere from any part of the house.
And we can draw a comparison between our brain and this house. It is not built of bricks but of neurons. And it works day and night, thanks to the electricity and chemistry between the neurons. We can fill the rooms with experiences, feelings, memories and studies, so that it can go on working. Let’s go from top to bottom to get to know the house.
The attic would be the neocortex, the outer layer measuring just a few millimetres and made up of grey matter. If you can’t find a solution to a problem, blame the neocortex, because it’s the part that does that work. It is the rational thinking side, the side that makes human beings human. It uses logic, and processes emotions that are conscious. It is also critical and creative. Even though it is essential for human beings, we don’t yet know it fully.
The first floor rooms are the right and left hemispheres of the brain. In general, the stimuli received by the left-hand side of the body are processed in the right hemisphere, and vice versa.
Each hemisphere processes information in its own way. The left one is the part that calculates; it is communicative, analytical, specific and logical and is capable of making complex plans. The right one is sensitive, imaginative and deals with things as a whole, without making any distinctions of divisions.
But the information received by one side is received by the other immediately, because they are connected. So the response is a joint one.
The ground floor is the limbic brain, the part that deals with the emotions. The most primitive emotions come from there: it is the one that sounds the alarm when we are faced with a threat, the one that detects false smiles, and that one that creates the desire for a person or video game we like…
It responds almost automatically when it receives an external stimulus, in other words when we smile, or escape, or… But when receiving a stimulus, almost immediately the information reaches the neocortex, thanks to the stairs. And in the neocortex a rational plan is prepared: if it confirms that the initial response was the right one, the body will continue with the response it made (smile, escape…); but, if the response was not the right one in the cortex’s view, it gives an order to stop the initial reaction.
That explains why small children have terrible tantrums: from the moment we are born we are capable of receiving stimuli in the limbic brain, but as new-born babies our cortex is not yet mature. That is why babies have less control over their emotions than adults.
In the basement there are snakes. No, not really, but that part of the brain is a remnant that comes from the reptiles and is called the reptilian brain. It is the oldest, most primitive part. It controls our basic bodily functions, for example our pulse rhythm, breathing. That part of the brain does not think and does not feel; it goes straight into action, it is very instinctive.
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