An important feature that was developed in the twentieth century is the way that research is conducted. Since every single person’s brain damage is different, cognitive neuropsychologists study only single cases instead of groups of people, or syndromes. Psychologists study the mind by looking at people who lost some sort of function after brain damage occurred. For example, if a person could recognize both faces and objects before brain damage occurred, but then after brain damage in a certain part of the brain they could only recognize faces and not objects, then psychologists can make inferences about the functions in certain modules of the brain.