The brain can process as much as 400 billion bits of information a second, but humans are aware of only about 2,000 bits a second. In terms of visual processing, the brain can effectively process only about 1 percent of the information that it takes in. This is because of specific neurons that selectively filter out unimportant visual information.
More facts about the brain:
Despite the popular belief that humans use only about 10 percent of their brains, there’s little scientific evidence to support this. Research suggests that almost all parts of the brain are active to some degree almost all the time.
Though the brain represents only about 3 percent of the body in terms of weight, it uses more than one-fifth of the body’s energy.
The average American is thought to take in about 3.5 zettabytes of information per year. That’s about 122,000 gigabytes per second — or more information than could be stored on 20 of the largest external hard drives commonly available in early 2011.