I am studying Natural Language Processing, so I have been interested in how humans learn language, in order to understand if the process can be replicated such that a computer can learn a human language. I think we would have to read the actual paper to really understand their findings, but the main thing I took away from this is: in order for a child to learn a language the parents apparently subconsciously alter the way they speak (whether it is just to or also around the child), language learning appears to be tied to psychical locations and children seem to rely heavy on feedback by their care takers.

That would be an indication that there is a limit to what computers can learn about human language by analyzing textual data (like e.g. Google Translate does). This is related to the poverty of the stimulus argument in linguistics. (http://en.wikipedia.org/wiki/Poverty_of_the_stimulus)