The article is bull. This happens because your brain is predictive, not because there are magical "high-level" areas of the brain that don't pay attention to "lower" details. That's not how it works at all.

The brain transmits information between parts of it. A -> B -> C -> ..., with A, B, and C being sets of neurons (so one arrow is not just one connection, but somewhere between thousands and millions).

Whenever you're doing anything with your brain, you can simplify to this situation : every part of your brain is attempting to provide inputs to every other part. When multiple inputs are coming in, a selection is made (1) it wants correct input data (2) faster input data is better (3) when a "best" set of data is found, attention provided to any other signal will fall off exponentially.

This is normally very useful. Say you're jumping over a rock. You've done this before, so the part of the brain controlling your legs wants information ... "what's happening". And 2 parts of the brain will provide. One part will ultimately come from the sensors in your leg. But it's too late : by the time the sensors say you've hit the ground, it'll be ~0.05-0.2 seconds after you've hit the ground, potentially too late to compensate without falling over.

Fortunately, when you started the jump, a piece of your memory also said "hey, I recognize this, here's what's going to happen", and your leg control system will compare the values of the sensors for a while, agree with the memory, and start responding to memory input instead of sensor input.

Meaning your brain is responding to events it could not possibly have sensed. If you're looking for this behaviour, you'll see it everywhere. (In practice, of course, your brain also has a "physics simulator" that will provide input).

Assuming you've got good components providing all sorts of inputs, this mechanism is fantastic. You can look at something for a bit, have a simulation routine in your brain "synchronize" to it, look away to something else, synchronize to it, and then respond to both stimuli simultaneously despite your sensors (say, eyes) not actually capable of observing both stimuli.

Unfortunately, when you're re-reading a text you've written, the spell checker in your brain will switch to what you remembered writing down, and after a short while won't care what your eyes are actually reading any more. So unless the reading method calls attention (which it will only do in WTF cases), you'll miss any spelling errors.

Then you have the following 2 parts of your brain :

* a reading method that is providing outputs that contain the spell errors, but isn't actually connected to the spell checker any more, various other pieces of your mind might pay attention to it because they've got nothing better to do, and this might result in capturing attention, but probably won't.

* the memory, providing the correct input, connected to the spell checker

(in fact, shortly after that, the conscious part of the brain that is attempting to spell check will realize that the chance of getting an "error" signal from the spell checker is very small, and will "predict" that the spell checker will return an "OK" for the entire text and simply not listen for other signals anymore).

In short : do NOT count on humans (or animals, for that matter) to find small errors in repeating patterns. Write a short python function to do it for them.

I like to say that human minds respond "faster than light". In a sense, they do. You see this in martial arts championships (e.g. https://www.youtube.com/watch?v=a4lX0fKDTD8 ), where the outcome of an attack is determined before the first signals go out to the muscles, and these fighters are acutely aware of that. You see neither fighter is looking at anything other than his opponents' face. Everything else mostly comes from the predictor. This then often results in the situation "I'm going to go for left top attack, change the balance between my shoulders to X, then step 2 is ... Oh no crap he's seen my plan, abort". Of course, if you haven't fought karatekas before you won't be able to play that game, and you'll be very predictable to them ... But for spell checking this sucks.

I can't believe I actually had to have my spell checker correct "spellchecking".

It also means that, for example, you want to endlessly mesmerise a human being, you have to give it a signal it superficially thinks it understands (so it gets deep into the brain, and gets a lot of different components involved in analysing it), but contains an obvious "core" random component, so the brain will never successfully predict it for any period of time. Ideally it should have random signals at multiple levels of meaning.

Such a signal, however, would be very bad for you. But addictive.