PowerPoint Presentation

[Audio] Can you read in the car? if so consider yourself pretty lucky for about one third of the population looking at a book while moving along in a car or boat or train or plane quickly makes them sick to their stomach. But why do we get motion sickness in the first place? Well, believe it or not, scientists aren't exactly sure. The most common theory has to do with mismatched sensory signals. When you travel in a car, your body's getting two very different messages. Your eyes are seeing the inside of the vehicle, which doesn't seem to be moving. Meanwhile, your ear is actually telling your brain that you're accelerating. Wait your ear. Yeah, your ear actually has another important function. Besides hearing in its innermost part lies a group of structures known as the vestibular system which gives us our sense of balance and movement inside. There are three semi circular tubules that can sense rotation, one for each dimension of space. And there are also two hairline sacs that are filled with fluid. So when you move the fluid shifts and tickles the hairs telling your brain whether you're moving horizontally or vertically with all these combined, your body can sense which direction you're moving in, how much you've accelerated, even at what angle. So when you're in the car, your vestibular system correctly senses your movement, but your eyes don't see it, especially if they're glued to a book, Thus, the Motion sickness happens the most during a Non driving related activity, and because of the vestibular system, head movement is a key to understand motion sickness.