There have been various studies conducted in the past that have developed concepts and theories on localization of function, also known as functional specialization in the human brain. The localization of function theory suggests that different areas and parts of the brain belong to different bodily functions such as cognitive language, visual reception/perception, and motor deficit or motor neglect. Precisely this topic, relatively new compared to the history of humanity, has acquired scientific credibility only recently, in the last two centuries, thanks to the help of Paul Broca and Carl Wernicke. These two figures are monumental, in terms of promoting the idea and concept of localization of function that were supported by their clinical case studies. There have been rashes of other studies that contain significant relevance and evidence that strengthens location theory, such as the empirical studies of Phineas Gage and Henry Gustav Molaison. Phineas Gage was one of the first documented cases of severe brain trauma and brain injury. . He was an American railroad construction foreman who had suffered a near-fatal experience on his construction site. On September 13, 1848, Gage was working with his crew of members to prepare a roadbed for a railroad near Cavendish, Vermont. His goal and task was to add explosive powder and a fuse which he would compact into the holes of the rocks to clear them. However, when he used a tool, known as a tire iron, to press the explosive, the powder reacted and exploded on contact. The explosion drove the tire iron into his skull, which entered through his left cheek and exited through the upper right side of his skull. Gage was, to his amazement, conscious on the spot and was in the middle of the map of neuroscience as it is today. HM, allowed doctors to observe the brain to an experimental standard, in order to derive compelling evidence to essentially be able to understand the brain. These two patients were major contributors to the theory of localizing the functions of the human brain, so that the psychological and medical world could gain knowledge about how the brain works on a cognitive and biological level. Works Cited http://en.wikipedia.org /wiki/Functional_specialization_(brain)http://findarticles.com/p/articles/mi_g2699/is_0002/ai_2699000205/http://www.enotes.com/gale-psychology- encyclopedia/localization-brain-function>http:/ /neurophilosophy.wordpress.com/2006/12/04/the-incredible-case-of-phineas-gage/http://www.nytimes.com/2008/12/ 05/us/05hm.htmlhttp://en .wikipedia.org/wiki/HM_(patient)http://en.wikipedia.org/wiki/Phineas_Gage