In this chapter, Cairo compares the human mind to that of a computer. He does so by saying the hard drive of a computer is like our long term memory and the RAM is the short term memory. We can only move so many things around. If we store things in our brain like folders on a computer, I’m curious to see how many sub folders an average human would have. I would imagine that each layer of a folder is a general thought of an idea and the deeper down the sub levels you go, the more detail about a topic your brain uncovers.
The bottom-up process refers to the brain perceiving preattentive features such as shapes, edges, relative sizes, and patches of color. The brain then attempts to match this with the visual working memory to make out an image. The top-down process occurs when the brain taps into the long-term memory and works with the visual working memory to interpret a thought. Both processes meet at the visual working memory to complete a thought process. Iconic memory is a very short-term storage for visual information. The purpose of iconic memory is to keep a visualization of the world for the brain to later interpret.
Some infographics will use realistic images while others use abstract. Abstract images allow a person to focus on the thought without getting distracted by the details in an image. Realistic images are used to represent something with accuracy.
This illustration shows the bottom-up and top-down processing.
This link explains how the brain interprets things such as faces by reading features like a bar code.