How can we see what we're imagining but still see what is correct in front of us? – Malala Yousafzai Class, Globe Primary School, London, UK.
This query is at the center of a serious problem for brain scientists. Say you're daydreaming at school – you possibly can keep your eyes open and concentrate on the colours and shapes within the classroom and the movements of your teacher and classmates, all of the while enthusiastic about whatever you're pondering. are or imagine can “see” it. .
These two forms of seeing are completely different, but they each occur in the identical area behind our brain. Visual cortex. Messages from different places could cause the visual cortex to activate, and at any time when this happens, you “see” things.
To understand how this happens, imagine that you just are the brain. You are locked inside a skull – a dark, silent vault. You are answerable for a body, and also you in some way must know what is occurring on the planet around you with a purpose to lead that body successfully.
One place where messages can come from is your eyes: light bounces off things around you and enters your eyes (in the event that they're open). Then the sunshine is targeted. Retina – A skinny layer of light-sensitive cells on the back of your eyeball.
The retinal cells then send messages to the visual cortex via the optic nerve. there, Different parts of the visual cortex Start decoding colours, edges and contours and movements and faces.
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The brain then puts all these visual messages back together, allowing you to see what's around you.
Imagining things
Remember, so far as the brain is worried, it doesn't matter where the messages are coming from – when the visual cortex is energetic, you're seeing.
So messages can also be coming from other parts of your brain – and this happens while you see things that you just visualize, remember or dream.
For example, sometimes while you hear a song you remember where you last heard it. Sound could cause a cascade of activity within the brain: messages go from the parts of the brain that hear, to the parts that remember, and eventually to the parts that see – and that's the way you experience the memory. Is.
Patterns and predictions
This explains how your brain manages two alternative ways of seeing. But it takes one Lots of energy Your brain to see what's happening around you, based on the messages your eyes receive. So there's one other trick the brain uses to see, to assist itself avoid wasting effort: it tries to predict what's going to occur based in your past experiences.
Even before children are born, they already are Learning about patterns which exists on the planet. As children get older, they use these patterns to predict what is going to occur next.
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For example, the primary time a toddler sees their father walking around a corner, they might think he has disappeared, and develop into anxious. Then, when the daddy returns, the kid could also be surprised and delighted.
But after this happens just a few times, the kid begins to expect that his father will come back across the corner, and isn't any longer surprised.
Balancing Act
So, your brain is definitely creating what you see on a regular basis, based on messages from different places in addition to your expectations.
The brain maintains a fragile balance between these messages and expectations, to show you how to navigate the world, and to conserve energy.
So if the teacher calls your name when you're daydreaming at school, your mind quickly shifts from imagining things to paying close attention to the messages out of your senses that the classroom is about. what's happening