Answer:
Alejandro damaged medulla, belongs to the hindbrain.
Nikka has damaged limbic system, amygdala, which belongs to the Forebrain.
Step-by-step explanation:
The hindbrain is the division of the brain that is responsible for all the functions and activities that are crucial for a human being. All the functions that we can't live without, for example: the rhythm of our breathing, sleep, being awake, motor activity etc.
It is one of the three parts of the brain, and the other two are midbrain and forebrain.
When it comes to Nikka, she injured her forebrain, more precisely, limbic system and amygdala. Amygdala's role is to collect emotion, memories and instincts.
Amygdala is responsible for the fear, detecting it and preparing ourself for potential emergencies. There are two amygdalas in each part of the brain.
Amygdala is responsible for perception of emotions, like fear, anger, sadness, as well as controlling the aggression. It stores previous events in our life so we can use them as the warning if a similar situation occurs.