Abstract: Sign language is the daily used language of deaf people, while spoken language is that for hearing people. Here we reviewed the studies on neural mechanisms for both comprehension and production of sign language and spoken language. Particularly, we compared the neural mechanisms of both languages from different processing level, including word, sentence and context. We found that the two languages activated a similar set of brain regions. Language production mainly activates the anterior part whilst language comprehension activates the posterior part of the brain. The more complex processing is associated with more-involved brain regions, especially the right- hemisphere regions. The differences between two languages are: 1) Right hemisphere is more engaged in sign language comprehension. 2) The left supramarginal gyrus, inferior parietal lobule are more engaged in sign language comprehension. These findings shed deep insights on some important issues including the origins of language, plasticity of brain and education of deaf children.

Key words: language, deaf, MRI, comprehension, production