Initially, when a subject is confronted with bad news that is too unbearable for the person, then the subject may react in denial, or not believe the news that has been presented at hand as a way to cope with the pressures and changes that come with the traumatic experience.
Denial
your dog died
No! I dont believe it.
Repression is the act of subconsciously repressing, or hiding traumatic experiences from memory in order to protect a certain individual from experiencing certain discomforts as a result of experiencing that pain. This term has been coined motivated forgetting and is often occurred from the ego as a way to protect an individual.
Repression
Its ok! He's not really dead.
Regression occurs as a defense mechanism when a person is placed in a stressful situation that triggers certain hormonal characteristics within a specific person. The act of regressing psychologically occurs when a person regresses to a previous stage of development because it helps that individual cope with the situation at hand.
Regression
I feel just like a kid!
Displacement involves when the ego of a subject finds somewhere to displace their anger elsewhere at a foreign object, or at oneself. This may happen because a subject isn't able to cope with the traumatic experience or occurs when a person is traumatized that they were capable of executing an action previously thought impossible.
Displacement
SHUT UP MOM! ITS ALL YOUR FAULT
Rationalization is the action of rationalizing a situation to adapt to more suitable situations than the one present. This involves a subject making excuses for the behavior of themselves or excuses for the experience itself within the trauma as a way to protect the ego from any damage.