In the movie Inside Out it was shown that the islands that were made in Riley's head started collapsing. So, exactly what was happening to Riley's psychology when this process of collapsing was happening?
Those Islands were Personality Islands, which represent parts of her personality:-
Family Island - represents her love for family.
Goofball Island - represents Riley's childhood goofiness.
Friendship Island - represents Riley's sense of friendship, especially with her best friend from Minnesota, Meg.
Hockey Island - represents her love for hockey.
Honesty Island - represents her honesty.
Now the collapsing of an island means her personality is now lacking in those areas. She lost her love for hockey when Hockey island collapsed.
So as we have seen she loses her personality traits with each collapse, and even the control room was freezing. So without any personality island and freezing of control room, she will be personality-less/emotionless. (A Lost girl with no emotion at all.)