Try putting your finger horizontally over the middle, and see how the colours of the blocks change instantly. What before was very distinctively two colours, blend into the very same grey colour.
What’s happening here?
This is a great example of what is called “top down processing”.
Every second of every day, your brain is bombarded with all kinds of sensory input, that you receive via your senses; eyes, ears, tastebuds, skin and nose.
When the information enters your brain, it does so in the form of raw data; you receive sound waves through your ears, light waves through your eyes, smell molecules through your nose etc.
Your brain must take this raw data, and, by using multiple areas of the brain, build a comprehensive experience – your reality – out of this data – kind of like the 1s and 0s of a computer’s binary system become something meaningful on your computer screen.
Now, if the brain had to do this from the ground up for every little thing that enters our system, we’d experience a system overload, and we would hardly be able to get out of bed in the morning.
This is why the brain forms a set of “ground rules” or “rules of thumb” that is applies to every day sensory items, that it’s seen a million times before.
It has, in other words, learnt that “if A then B”. Like in the example above, the brain knows that the shadows in the middle indicate that these are two separate things, so it calculates its own sensory experience accordingly – making the item above darker and the item below lighter, to account for the difference in light exposure.
As soon as you take away the indication of this being two distinct items, the brain doesn’t see the reason to recalibrate, so you see that the two items are actually the very same colour.
Why does this matter?
This matters, because your brain does this with more than just sensory experience. It does so also with communication between people, and with how you make sense of the things happening around you. A look on someone’s face will the processed according to the top-down rules your own brain has learnt over the years.
This is the reason for why you can often hear these sentences in an argument between two people: “Stop shouting!” – “I’m not shouting!” – the two brains take the ambiguous sensory input of the voice, and apply the same top down calculations to it, and voilá, you have yourself one person that in all earnesty experiences a person’s voice as “shouting” while the other one doesn’t at all experience shouting.
This is very important to be aware of, especially when you have difficult experiences in your past. Your brain learns, and applies the principles it acquired in the past, to your present. But maybe the situation you’re in today is not the same as the situation you were in when you were a child and your brain learned its principles.
So knowing that our reality is filtered through the lens of earlier experiences is important, because it gives you the freedom to explore how your present is different from your past, and how things might have changed around you – or inside of you.
This is a part of what we’re working with, in treatment. To free yourself from the confines of our past.
It’s not always easy.
But it’s by far the most giving, fruitful and exciting thing in the world!