The human sensory impressions repeatedly prove to be particularly deceptive. It is therefore obvious that the perception of things is moving into the focus of experimental psychology. For through seeing, hearing, smelling, tasting and touching, people experience information that is further processed cognitively and that helps MindThings to develop. In the permanent exhibition “KopfSachen – MindThings”, historical instruments and tests from the Psychological Collection are presented. Intelligence and competence tests, optical illusions, haptic phenomena, precision mechanical work and the history of the subject area are vividly explained.