Our brains are amazing. And even if you’re not aware of it, your brain is like a code-cracking machine.

I’m sure you’re familiar with the paragraph below, where the first and last letters of the word are correct but the rest of the letters are muddled.
And you can still read it, right?

“Aoccdrnig to rscheearch, it deosn’t mttaer in waht oredr the ltteers in a wrod are, the olny iprmoatnt tihng is taht the frist and lsat ltteers be at the rghit pclae. 
The rset can be a toatl mses and you can sitll raed it wouthit porbelm.
Tihs is bcuseae the huamn mnid deos not raed ervey lteter by istlef, but the wrod as a wlohe.”

And how about if the letters are replaced with numbers?

“7H15 M3554G3 53RV35 7O PR0V3 H0W 0UR M1ND5 C4N D0 4M4Z1NG 7H1NG5! 1MPR3551V3 7H1NG5!
1N 7H3 B3G1NN1NG 17 WA5 H4RD BU7 N0W, 0N 7H15 LIN3 Y0UR M1ND 1S R34D1NG 17 4U70M471C4LLY
W17H 0U7 3V3N 7H1NK1NG 4B0U7 17, B3 PROUD! 0NLY C3R741N P30PL3 C4N R3AD 7H15.”

How do we read them?

According to Marta Kutas, a cognitive neuroscientist and the director of the Center for Research in Language at the University of California, San Diego, the short answer is that no one knows why we’re so good at reading this garbled nonsense. But Kutas has a strong suspicions that context is very important.

We use context to pre-activate the areas of our brains that correspond to what we expect next. For example, brain scans reveal that if we hear a sound that leads us to strongly suspect another sound is on the way, the brain acts as if we’re already hearing the second sound. Similarly, if we see a certain collection of letters or words, our brains jump to conclusions about what comes next.

We use context to help us perceive.

It’s not a perfect system and in the above passages you probably didn’t get every single word right just from knowing what came before it. You only thought you were reading the examples perfectly, because you automatically (and subconsciously) went back and filled in any gaps in your knowledge based on subsequent context — the words that came later.

Additionally, in the case of the first example (the words with jumbled middle letters), it helps that your brain processes all the letters of a word at once, rather than one at a time. Thus, the letters serve as contexts for each other.

In the case of the second example, a 2007 study by cognitive scientists in Spain found that reading such passages barely activates the brain areas that correspond to digits. This suggests that the letter-like appearance of the digits, as well as their context, has a stronger influence on our brains than their actual status as digits. The researchers think some sort of top-down feedback mechanism (our consciences telling our sensory processors what to do, sort of) normalizes the visual input, allowing us to ignore the funny bits and read the passage with ease.

Even with today’s emphasis on communication that attracts our senses with for example motion and sound, words are still important. The right words can tap into people’s emotions and hold their attention while conveying a message.