Have you ever noticed how we are able to block out all of the background noise around when we are trying to focus on something very important? That important something could be homework, studying, favorite television show, sports game or even a conversation with someone. Our brains are capable of something called selective attention. Selective attention is selectively concentrating on one particular event going on in the environment, and ignoring everything else.
Selective attention is constantly at work, if our brain had to constantly interpret everything going on around us, our brain would be overwhelmed. There are many examples of selective attention. One example I can think of is when your trying to watch football on Sunday but your family members around you are making a bunch of noise, yet you are still able to focus on the game entirely. Someone then tries asking you a question but you don't hear them at all until they pull your attention away from the game completely. Sometimes our selective attention doesn't work. For an example, when I am writing a sentence but then I hear someone talking about a different topic, I find my self writing what that someone is talking about.
Here is a selective attention test.
Knowing about selective attention, we can grasp a little bit on how complex our brains really are.