If we look into the skull at the front of the head, we will find the prefontal area of the cerebrum. What does physiology tell us about the function of this area? A book entitled, Essentials of Anatomy & Physiology, says about this area: "The motivation and the foresight to plan and initiate movements occur in the anterior portion of the frontal lobes, the prefontal area (see Fig. 25). This is a region of the association cortex... The book also says: In relation to its involvement in motivation, the prefrontal area is also thought to be the functional center for aggression..."

Fig. 25

So, this area of the cerebrum is responsible for planning, motivating, and initiating good and sinful behavior, and is responsible for telling lies and speaking the truth. Thus, it is proper to describe the front of the head as lying and sinful when someone lies or commits a sin, as the Quran said: "...a lying, sinful naasiyyah (front of the head)!" Scientists have only discovered these functions of the prefrontal area in the last sixty years, according to Professor Keith Moore.