Dr. David Berson

confirming that you just made a movement that you will.

A lot of this is happening under the surface of what you're thinking.

These are reflexes.

Maybe the best way to think about how these two systems work together is to think about what happens when you suddenly rotate your head to the left.

When you suddenly rotate your head to the left, your eyes are actually rotating to the right.

Automatically, you do this in complete darkness.

If you had an infrared camera and watched yourself in complete darkness, you can't see anything.

Rotating your head to the left, your eyes would rotate to the right.

That's your vestibular system saying, I'm going to try to compensate for the head rotation so my eyes are still looking in the same place.

So the brain works really hard to mostly stabilize the image of the world on your retina.

Now, of course, you're moving through the world, so you can't stabilize everything.

But the more you can stabilize most of the time, the better you can see.

And that's why when we're scanning a scene, looking around at things, we're making very rapid eye movements for very short periods of time, and then we just rest.

But we're not the only ones that do that.

If you ever watch a pigeon walking on the sidewalk, it does this funny head bobbing thing.

But what it's really doing is racking its head back on its neck while its body goes forward so that the image of the visual world stays static.

Really?

And you've seen the funny chicken videos on YouTube, right?

You take a chicken, move it up and down, and the head stays in one place.

It's all the same thing.