I think parts of the Brain that is responsible for talk and language is already identified. In addition, some genes also identified. But I think work is not completed yet. However, the answer for your question and other related questions will be answered clearly after the Connectomics project. The project is just started one year ago.
Sutarmo, I found this paper not bad, hope it can serve: " In the present article, we discuss how this gene was discovered, what it might do, how it relates to other genes, and what it could tell us about the nature of speech and language development."