Perception is a construct
I've been reading the book The Idea of the Brain by Matthew Cobb. In the chapter titled "Inhibition," he explains how in the late 19th century we understood that the act of seeing is not merely capturing whatever is in front of us, but that what we see is largely constructed by our brain.
This is evident in how we interpret the third dimension from our stereographic view, and how the blind spots in our eyes are not apparent in our vision.
I've also found it fascinating how, when searching for something—like a pen on a desk—we can look repeatedly and still fail to see it. I was flabbergasted to learn that our brain produces a familiar image of the desk, but unless we deliberately examine it, we only see the preconceived image of the desk without a pen on it.
This is even more apparent in typo errors, where you can look at a sentence many times but still not see the typo in one word, as the brain is not carefully perceiving each word one by one, but constructs the sentence much faster by interpreting words from their preconceived visual patterns.
