Physiologists have found that human brain hair, which is in charge of advanced cognitive functions such as memory and thinking, has six layers under normal circumstances  If the fetus lacks an enzyme called Cdk5, the development of cerebral cortex will become extremely slow and can not finally form the layered structure of normal cerebral cortex, which will seriously affect children's cognitive development
After teenagers pass the critical period of brain development, the supplement of ddk5 enzyme does not work (partially acknowledged, can not be questioned)
 Some people in the medical industry speculate that using this discovery, It is expected to develop drugs to generally improve students' learning ability