Take a look at your hands. Stick out your thumb as if you are trying to hitch a with your right hand. Now, try to do the same thing with your left. Can you do it?

For some people, this task isn’t as easy as it may seem. Mike Gazzaniga, the “father of split-brain syndrome”, had been studying a patient who had undergone a corpus callosotomy, a procedure which splits the brain into two halves to treat some forms of epilepsy. He saw that the patient had difficulty processing images depending on where in his field of vision they appeared.

When we see an image in our left eye, it is sent to the right side of the brain, and vice-versa. The image is then be sent to the dominant language centre, in the left side of the brain, to be processed into something we understand. However, if a patient has undergone a corpus callosotomy, that pathway will be disrupted, leaving them unable to describe what they have seen or able to follow instructions with their right hand.

This research has helped to provide insights into how our brains are organised and its capabilities are compartmentalised.

Learn more, by watching the video above.

Join one million Future fans by liking us on Facebook, or follow us on Twitter or Instagram.

If you liked this story, sign up for the weekly bbc.com features newsletter, called “The Essential List”. A handpicked selection of stories from BBC Future, Culture, Capital, Travel and Music, delivered to your inbox every Friday.