you are likely to find Laser in/at/on Laboratory. you are likely to find Scientist in/at/on Laboratory. Psychologist is a type of Scientist. Psychologist is related to Mental. 
Gravity is related to Fall. 
Laser --AtLocation--> Laboratory <--AtLocation-- Scientist <--IsA-- Psychologist <--RelatedTo--> Mental 
Gravity <--RelatedTo--> Fall 