It's all down to your brain...
While we're sure there are those that can happily spend their car trips reading a magazine or a book without any ill feeling, we're certainly not one of these people.
Many people, including ourselves, start feeling nauseous as soon as they read two paragraphs of a book in a moving car, but science finally has an answer as to why this is happening.
Your brain thinks you're being poisoned...
Neuroscientist and author Dean Burnett explained on
NPR's Fresh Air recently that the brain gets confused with the contrasting signals it is receiving.
The thalamus is responsible for interpreting these sensory signals that the body sends.
When you're moving around normally, your muscles are in motion and your eyes can see the distance you cover and you're inner ears are providing you with balance.
These balance sensors in your ears are “little tiny little tubes full of fluid,”according to Burnett, “and the motion of that fluid tells us where we’re going. So, if we’re upside down, we can tell. And if we’re going fast, we can tell, because this fluid just obeys the laws of physics.”
But when you're in a car, these messages become somewhat muddled as your muscles are sitting still, yet your eyes can clearly see you're moving and the vibrations from the driving are being picked up by the fluid in your inner ear.
These mixed messages confuse the brain as it cannot decide whether the lack of movement from the muscles is telling the truth and you're in fact not moving, or the inner ear and eyes are to be believed.
The confusion is exacerbated when you put reading into the mix and there's a sensory mismatch. But because of evolution, the brain believes the only thing that can cause a sensory mismatch is some kind of neurotoxin or poison.
The brain then initiates the standard response of trying to clear the body of this toxin... by violently projecting it from your mouth as vomit.
So why does this happen to some people and not to others? Well, Dean Burnett doesn't have an answer to that because there's no reason it should happen to some people and not others, it's simply a "quirk of development".
