Localization of function taken to the extreme Work by Broca and others showed that particular cognitive functions, such as language, are controlled by specific areas of the brain. This led to the popular belief that all aspects of thought, emotion, and personality can be located in the brain, culminating in the pseudoscience known as phrenology, developed by the German physician Franz Joseph Gall. Gall and his followers believed that the mind consists of mental faculties that are located at specific sites in the brain. By feeling bumps on the skull, phrenologists claimed they could infer the size of various areas and describe a person’s psychological characteristics. Although soundly discredited, phrenology influenced nineteenth-century psychiatry and is broadly consistent with modern neuroscience’s idea of localization of function.