How can the brain sometimes read words even when the middle letters are not in the right order or are replaced by

Question: How can the brain sometimes read words even when the middle letters are not in the right order or are replaced by numbers?
- Keywords:
  brain,
  perception,
  reading
Asked by Meg to Chris, Rebecca on 26 Jun 2015.
- Rebecca Dewey answered on 26 Jun 2015:
  
  The idea is that your brain is so used to seeing the patterns that we see in words, and it’s so good at picking out those patterns, that it just picks out the patterns *it expects to see* and not the ones that are actually there. In actual fact, it’s not quite as good as we think and often gets stuck if it doesn’t immediately pick out the most useful letters. For example, some letters are more useful (tell you more about the word) than others. There are fewer words with an ‘x’ in than words with an ‘e’ in, so x is a more useful letter to see than e.

Question: How can the brain sometimes read words even when the middle letters are not in the right order or are replaced by numbers?