How do you select information?

Even before you pay attention to something, you have already filtered out a lot of background information. Your senses generally tell your brain about your surroundings only if they change - so you don't notice the continual hum of a fridge or the feeling of shoes on your feet, for example. When you want to pay attention to a particular thing, like your friend's face in a crowd, it's as if your brain uses a 'spotlight' to highlight the relevant information.

Your brain uses a 'spotlight' to pick out someone's face in a crowd.