Close your eyes (figuratively...unless you can read through you eyelids in which case you probably have better things to do) and picture yourself in a small room, electrodes are taped to your legs, arms, and chest, you have an IV in your arm where you have just been injected with a nuclear radioactive substance and the nurse tells you in a cheerful voice to lay still and just 'breath normal' for the next 9 minutes.
What do you do?
If you are anything like me, you immediately become super aware of your breathing and wonder what 'breathing normally' means. You start taking nice deep breaths, trying to make sure that they are even, thinking that is how you normally breath. You realize you never breath that way so you switch to small shallow breaths to even everything out. Then you quickly discover that breathing that way is depriving your body of precious oxygen so in response you take a few super deep breaths.
Gah, how is it you normally breath?
You begin to panic because you think that maybe the image won't turn out now because of your spoatic breathing patterns. They will have to do the test again and this will throw off your schedule. You will be forced to go get more blood drawn from the mean nurse from Monday who will keep you hostage until she finally gets a sample of your sputum. You will also be injected with more dye which will turn you into a superhero of some sort. Except you will probably end up being a boring superhero that is able to identify the exact colour of wall paint or has the ability to grow their fingernails at super speeds. Hey look, you finally stopped focusing on your breathing.
The nurse returns to ask how everything is going and you say great because you don't really know what else to say. As she walks out of the room she reminds you to 'keep on breathing normally'.