When you think about it, five senses are actually quite a lot.
Your eyes never turn off, nor your ears. Your sense of touch? Constant. These are not instruments which we turn on and off at will, they are constantly-running diagnostics and windows into the outside world that are always on and always sending signals.
But you don’t feel the glasses on your face; you don’t notice every time your shirt rubs against your arm, even though every time you move, it does. And what about conflicting messages? Like when you know you’re sitting in your parked car, but the guy pulling out next to you makes you spontaneously jam your foot on the brake pedal? What causes your brain to make the decision whether to pay attention to one signal over another?
Researchers at the U of R are peeling back the mystery of that process. To do so, they asked subjects to sit in a virtual reality environment where dots on a screen indicated movement in one direction while the chair they sat in moved in another. These two stimuli – physical and visual – were altered to see which stimulus was trusted. The dots’ direction was also changed to make it more and less reliable than the feeling of movement. The subjects were asked to identify which direction they were moving in.
It turns out that, rather than a single decision made by the brain as a whole, individual neurons acting on their own performed some basic math to determine what the most reliable stimulus was. This calculation is performed by millions of neurons and the average response is what the brain ends up going with.
This sort of helps explain why no amount of understanding stops you from grabbing hold of your seat in an IMAX movie when the camera rolls and banks like a plane. Its not about intellect, its about some pretty basic computation done by individual neurons.
With that in mind, here’s a quick video from a great television show, Brain Games, on National Geographic. Watch how quickly even one sense can be fooled because your brain has to make these decisions about what to pay attention to: