Without ever knowing it, our brains are in a constant balancing act between learning too much from the past and incorporating too much new information from the present.
Filter bubbles can upset this balance because it surrounds us with ideas we already agree on and it removes from us some of the key prompts that make us want to learn.
Filtering has been around for millions of years. One of the functions that our brains have done forever is compressing data. (called schema). This helps us to not always see the world as new.
For example, once you recognize a chair, you will always know what it is and how to use it.
Our Schema can get in the way of our ability to clearly observe what is happening. For example, one study found that people add details to their memories of news stories shown to them. This happened because of the schemata the stories activated. Confirmation Bias is 'a tendency to believe things that reinforce our existing views, to see what we want to see.'
The filter bubble amplifies the confirmation bias because it only gives us information that confirms our beliefs. Consuming information that conforms to our ideas of the world is easy and consuming information that challenges us to think is difficult.