Here's a simple experiment you can perform to measure the flux of blood passing to your brain.
To start, you'll need a medium sized, serrated steak knife. Hold the knife firmly in your good hand, and saw at a 45 degree angle from your voicebox to your opposite ear. Next, with a beaker and stopwatch in hand, collect all the blood that sprays from your carotid artery for 15 seconds. You'll want to be careful to avoid cutting the jugular vein, as this might augment the flow rate. Then, simply divide the volume obtained by the time, and multiply by 2 to compensate for the other artery. Voila! You have now measured the rate of blood flow to the brain, and the best part is, nothing of value was lost.