Why you don’t remember everything you read

Why you don’t remember everything you read

In our society you have to learn a great deal from texts – take that seemingly never-ending flow of school books, for instance – that is why it is crucial that we construct a correct mental model. Luckily we have a critical brain to help us out.

Originally published in Dutch on leidenpedagogiekblog

Think back to your schooldays or college days. How much of your knowledge did you acquire through texts? How many books did you read? Even as you read this blog, you can understand the text without too much trouble. To do all this, your brain is hard at work. In every sentence you read, you process the words and the grammar. You also make connections with your own background knowledge and earlier portions of the text to understand the sentences. And you do all this in a matter of seconds. When you come to think of it, it’s actually an amazing feat for all these processes to take place simultaneously (or virtually simultaneously). Each new piece of information is fitted into your representation of the text in order to create a coherent and correct mental representation (your mental model of the text). So reading is a pretty complex business.

Our critical brain

However, the mental model cannot simply be adapted blindly in light of everything you read. In a perfect world, everything you read would be 100% correct, but in practice that is not the case. Texts may not be entirely correct… in any number of ways. They may contain factual errors, or even deliberate lies; they may contain contradictory information, or may contradict other texts about the same subject. To prevent our memories being flooded with incorrect knowledge, it is important that we check the information before we adapt our mental model to accommodate it. This process of checking new information before it is integrated into the mental model is known as ‘validation’.

What you know vs. what you read

The mental representation is validated against various sources of information, such as the reader’s background knowledge and information from earlier in the text. Take the sentence “The elephant flies”, for instance. When you read this sentence, alarm bells probably start ringing, because you know elephants can’t fly. But is it still a problem if you read the same sentence in a story about Dumbo the circus elephant? Probably not. So to understand the text, readers use information from their background knowledge and from the text itself, checking whether each new piece of information fits with what they know and what they have just read.

Learning from texts

Once a piece of information has successfully been checked, it is integrated into the reader’s mental model and eventually stored in their long-term memory. So validation processes play a role not only in how people read, but also in how people learn from texts. Both what you read and what you already know determine what and how you learn from the text and thus how you expand or adapt your knowledge. Of course all these processes occur in a flash, and people seldom pause to think about them. Investigating these processes gives us greater insight not only into how people read, but above all into how they deal with incorrect information and how the brain attempts to protect our mental model (and thus our memory) from this information. Thus, your brain makes sure you don’t remember everything you read. And given the increasing amount of disinformation and fake news on the internet, that’s probably a good thing too.