Books: How they're made and how your brain reads them

There is so much happening in your brain when you read. From recognizing shapes as letters to discovering empathy, our brains really get a workout when we read books.

In this episode, Ben Bergen from the Language and Cognition Lab at UC San Diego drops by to shed some light on how our brains process the meaning of words. We also learn how printing books has evolved and how the invention of the printing press brought worldwide change. And Newberry Award-winning author Kelly Barnhill shares a little of what’s going on in HER brain as she’s writing a story.

What happens in your brain when you read?

Whenever we read books we activate several parts of the brain. We start out with the visual cortex, back in the brain’s occipital lobe, to see and recognize letters. The temporal lobe, over by your ear, is engaged and helps figure out what sounds those letters correspond to, and the words those sounds make. The amygdala, part of the brain’s emotional center, plays a role in revealing a character’s feelings. The frontal lobe’s motor cortex is activated when we read about people doing things. For example, if you read a passage about a character running through the forest, the motor cortex lights up in the same way it would if you were the person running.

According to Albert Kim, a neuroscientist at University of Colorado Boulder, it takes just a couple hundred milliseconds for the visual cortex to recognize shapes after we first see them. We learn to recognize shapes as letters, letters as words and words as sentences. Kim uses electroencephalography (EEG) to measure neural activity while people read. Someone might read a sentence on a computer that looks like this: “The chef bought some flour to make a ________.” Readers will see a quick flash of light instead of a blank space. And in that split-second flash, Kim finds that most brains act as if they’re seeing the word “cake.” In other words, most brains are primed for a words before they come. We’re pretty good at predicting what comes next.

This same kind of experience holds true for emotions. Ben Bergen researches the meaning of words in his Language and Cognition lab at UC San Diego. He said that when you read emotional words, words that make you angry or happy or sad, a series of responses are released to recreate that same emotional experience in your brain. “When you read the word ‘sewage,'” Bergen said, “parts of your brain that create an experience of disgust start firing.” An entirely different emotional reaction occurs when you read a word like, “unicorn” — that is unless you really don’t like unicorns.

How the printing press changed the world

Johann Gutenberg’s printing press is often cited as the most important invention of the last millennium. In the 50 years leading up to his first printing press (1400-1450), there were about 12,000 books printed — and “printed” in this case means written out by hand. In the 50 years after Gutenberg used his press to print his first book (a copy of the Bible), 12 million books were printed. 12 million!


This episode was originally published on May 23, 2017. You can listen to that version here:

Books and the brain
by MPR