My friend does experiment on himself by pressing both carotid arteries wih both hands and he observed 2 differences 1.he felt pumping of blood in various parts like nose, forehead, behind head and 2.he felt dizziness it becomes weak his body then he remove his hands from carotid arteries so, which is correct observation between 1 and 2 to painless death for a person. I am finding my answer for knowledge gaining.