Your niece loves to play peek-a-boo. the way that you like to play is to put your blanket over your face and after a few seconds abruptly remove the blanket. each time that you remove the blanket, your niece acts like she is very surprised to see you. according to piaget, what concept does your niece lack?

The answer is object permanence.

Object permanence refers to the ability to understand that an object is still present and physically exists even if it is hidden out of sight. In this example, your niece lacks object permanence since she does not understand that you are behind the blanket even though you cover yourself with it or you are temporarily. 

You can drink laxative, or  do this exercise when you are sitting in the bathroom on the toilet. to relieve  constipation  fast or in about 1 minute, pinch your nose after your usual exhalation. start holding your breath. but do not mouth breath during this just hold your breath.