Rowan Sommers defends thesis on 17 June

Link to live-stream

“Did you see that big man with the little dog?” We find it quite normal to combine words to describe things around us. But actually, this is a particularly clever trick of our brains. It requires a flexibility and creativity that our artificial language models – no matter how clever – have apparently not yet developed. Even more extraordinary is the fact that we can combine an increasing amount of information across sentence boundaries. Think for example of everything you find out about Harry Potter when reading the book series. To do this, we need to be able to refer back to a person in an earlier sentence.

In this PhD thesis, Sommers investigated this phenomenon using EEG and MEG, two methods for measuring subjects' brain activity when reading. Among other things, he found that the frontoparietal network becomes activated when reading new reference words (compared to reference words that refer back to previously mentioned individuals). The frontoparietal network is often associated with the working memory, which allows us to flexibly manipulate information. He also used insights from neurobiology to program a computational language model that can build complex reference objects by grouping words together.