I read and hear this notion a lot that a person uses only 10% of it brain. However, I am unable to find evidences to back this claim. Is there a way to measure how much brain am I using? Hypothetically speaking, we only utilize 10% of it, then what happens with 90%? Is it none-functional? More to the point, say if we only use 10% then what a human will be able to do and accomplish if we start using it 80% and above?