People are able to save in the head several images seen in a second and compare them with the views in a second. The electrical activity of the brain has been measured to achieve this through electrodes and magnetic resonances. In this way, they have seen where this work is concentrated in a small area with a bottleneck appearance. In addition, this system allows to measure the memory capacity of each person.
In fact, an average of three or four images are preserved in memory; although some people only remember two images, others can save five or six. Researchers believe that this short-term memory capacity may be related to intelligence.