Gestalt psychologists have made substantial contributions to our understanding of:

Gestalt psychologists have made substantial contributions to our understanding of perception.

Explanation:

Psychology is the study of scientific behavior and mental process. A school of psychology-Gestalt psychology is established in the 20th century. The Gestalt psychology concentrates on the modern study of perception. Perception explains how the information is responded.

Gestalt theory of perception explains how the human eye observes visual elements. Max Wertheimer is one of the founders of Gestalt psychology. Gestalt psychology says that the scene is given more importance than its individual parts. Gestalt psychology can be generally stated as law of simplicity.

cannabis

explanation:

(assuming this is the us) google it. law states you can't have weed.