Brain Function: Selective Attention
To interact effectively with the people around you, your brain must constantly process large amounts of more or less complex information. However, it can only carry out a limited number of tasks at a time, so it needs to select the most relevant information, based on your needs at any given moment.
At this very moment, your brain has decided to focus almost exclusively on the visual information in this text and to downplay messages relating to the sensation of the clothes on your skin or the position of your legs. But we'll bet that simply mentioning this fact caused you to become aware of the texture of your clothes and the position of your legs. If so, you have just realized that your ability to remain focused is limited to specific information, but still somewhat flexible.
Certain functions governed by the brain are fairly automatic and unconscious -- for example vital functions like breathing or highly developed skills such as competitive running. As a result, you don't have to specifically focus on the level of oxygen in your blood in order to activate your diaphragm and fill your lungs.
Other functions require constant supervision. Understanding the message in these words requires that you concentrate on reading each sentence with some care. That means a more or less conscious and sustained mental effort and attention. Your attention span varies depending on the type of information you're looking for, and it relies on the proper function of much of your brain. Exercising your attention span by performing a variety of specifically designed exercises promotes the proper functioning of many areas of the brain.
The Three Major Components of the Selective Attention System
1. Your prefrontal cortex, located at the front of your brain, governs attention span and provides additional supervision; in other words, it determines what information is to be given priority and which cognitive resources are needed to analyze this information and eliminate any distractions.
In a situation where several conversations may be taking place simultaneously, such as at dinner with friends, you need to select the source of what you are being told in order to follow that conversation while damping down the sounds of the other conversations.
But human beings are not natural multi-taskers; your brain functions at optimal level when it only does one thing at a time. Male and female alike, if you ask it to do two somewhat complicated tasks at the same time, your performance levels for each will be reduced by half. People that we admire for their multitasking ability are actually high-performance individuals who can quickly and efficiently complete each of the tasks one after the other.
2. Certain situations require a detailed analysis of the stimuli you're taking in. Here various areas of the brain come into play, depending on the type of stimuli -- visual, auditory, gustatory, olfactory or tactile.
A visual search for a spatula in your kitchen drawer requires a quick but detailed analysis of the components of each of the utensils you come across, and the brain region involved is the temporal cortex, located above your ears. The better it works, the better and faster your search performance.
3. You sometimes also need to focus on the location of objects in your surrounding environment. This type of attention is called selective visuo-spatial attention and requires your parietal cortex, in the upper central part of your brain.
When you're looking for your car in a parking lot or a friend in a crowd, you use your selective visuo-spatial attention to weed out a recognizable face or object from a mass of others.