Abstract: Researches on language mechanisms of deaf individuals provide special viewpoints to explore the organization of the specialized language systems in the human brain. This paper reviewed recent lesion and functional imaging studies in this field and focused on: (1) the properties of sign paraphasia caused by left and right brain damages; (2) the activation patterns in the left and right hemisphere during the processing of sign language; (3) the activation patterns in human brain and the possible function of the posterior cingulate during the process of speechreading

Key words: deaf, sign language, functional imaging, paraphasia, speechreadin