Relationship among different sciences to respond to specific questions that a science can not solve alone, pushes the scientific world to the emergencing of new interdisciplinary courses .As a result, Linguistics as a science that studies about language(which is a complex human, social and cognitive phenomenon) needs other related sciences .Today too much attention to areas such as Neurolinguistics , Psycholinguistics,Sociolinguistics, Educational linguistics,Computational linguistics and Forensic Linguistics shows developing of interdisciplinary studies.
Neurolinguistics, which is the main point of this paper, is a branch of macro linguistics which emerged not more than a few decades ago. The main theme of this science is the relationship between language and human brain mechanisms. The main questions that Neurolinguistics tries to answer are as follow: How is language learned, processed and represented in the brain? In fact, Neurolinguistics wants to find more information about the biological organization of the first and second language function .On the other hand, it tries to solve the problem of thousands of patients around the world suffering from aphasia which neither Neurology nor linguistics is able to treat on its own.
The first part of this paper deals with the history of Neurolinguistics and the main theories on relationship between language and brain. The second refers to categorization of different Aphasia and the last part will briefly discuss language learning and biligualism.