Mental energy was a kind of energy that had no form or substance to it. Once it was sent out, it was hard for others to detect or defend against it.
Scientists discovered after multiple investigations that mental energy was a strange kind of brain waves.
Once someone awakened the Mental Gene, they would be able to send out these brain waves just like sound waves. There would even be a return echo once the brain waves hit any objects, and the pituitary gland would be able to sense the rebounded brain waves and perceive the surroundings from there. This was extremely similar to the echolocation ability of dolphins.
In addition, when this kind of brain waves was strengthened to a certain extent, it would manifest and could interfere with the thoughts of others, hypnotizing them or even causing them to be trapped inside an illusion.
This was the theory of genetic hypnotists.