Read and then spew in the Car
By Simonbook - 27 Aug 2016 in
So what’s happening there is the brain’s getting mixed messages. It’s getting signals from the muscles and the eyes saying we are still and signals from the balance sensors saying we’re in motion. Both of these cannot be correct. There’s a sensory mismatch there. And in evolutionary terms, the only thing that can cause a sensory mismatch like that is a neurotoxin or poison. So the brain thinks, essentially, it’s been being poisoned. When it’s been poisoned, the first thing it does is get rid of the poison, a.k.a. throwing up. And as a result — so, like, as soon as the brain gets confused by anything like that, it says, oh, I don’t know what to do, so just be sick, just in case. And as a result, we get motion sickness because the brain’s constantly worried about being poisoned.
For some people, this reaction is stronger than others. If you’re just riding in a car, you can look out the window and see the world passing by, which can calm that sickness response. For others, reading on a train is fine, because you can still look up periodically and realize you’re moving—but for others, as soon as you focus on a page and tune out the rest of the world (and other visual sensory information,) well, that’s when it all goes downhill.