How do you know where something is when you can no longer see it?
Researchers from the Massachusetts Institute of Technology, US, have found that the brain works hard to remember things you just saw by recoding the the image among neurons in the opposite side of the brain to where it was originally processed.
“You need to know where things are in the real world, regardless of where you happen to be looking or how you are oriented at a given moment,” says lead author Scott Brincat.
“But the representation that your brain gets from the outside world changes every time you move your eyes around.”
The study, published in Neuron, showed that what we see to our left is mapped onto the right side of our brain and vice versa. However, when the image disappeared from vision, that information was shifted to the other side of the brain, they found in animal models.
That means that when an object changes sides in your field of view, simultaneous brain frequencies shepherd the memory of when that object is from one side of the brain to the other, allowing us to still be aware of what’s around us even when we can’t see it anymore.
This memory information is stored by a new group of neurons in the prefrontal cortex of the opposite brain hemisphere and is wired to acknowledge the object in its new relative position.
This gives us the ability to look around without immediately forgetting where everything is.
“If you didn’t have that, we would just be simple creatures who could only react to whatever is coming right at us in the environment, that’s all,” says Miller.
“But because we can hold things in mind, we can have volitional control over what we do. We don’t have to react to something now, we can save it for later.”