Building sentence structure may be language-specific

Do speakers of different languages build sentence structure in the same way? In a neuroimaging study published in PLOS Biology, scientists from the Max Planck institute for Psycholinguistics, Donders Institute and Radboud University in Nijmegen recorded the brain activity of participants listening to Dutch stories. In contrast to English, sentence processing in Dutch was based on a strategy for predicting what comes next rather than a 'wait-and-see' approach, showing that strategies may differ across languages.

While listening to spoken language, people need to link 'abstract' knowledge of grammar to the words they actually hear. Theories on how people build grammatical structure in real time are often based on English. In sentences such as 'I have watched a documentary', the noun 'documentary' immediately follows the verb. However, in Dutch sentences, the word order may be reversed: 'Ik heb een documentaire gezien' ('I have a documentary watched').

"To find out whether speakers of different languages build grammatical structure in the same way, it is important to look at languages that differ from English in such interesting respects," says first author Cas Coopmans. "Findings based on English may not generalise to languages that have different grammatical properties, such as Dutch."

Audiobook stories

To investigate how people build sentence structure in Dutch, the researchers measured the brain activity of 24 participants who listened to Dutch audiobook stories in a magnetoencephalograophy (MEG) scanner.

For every word in the audiobook, the researchers determined how much grammatical information could be built. A 'top-down' strategy based on early prediction of upcoming sentence structure was compared to a 'bottom-up' strategy, based on integrating grammatical information at a later stage.

Predicting what comes next

Both sentence building strategies could predict activity in the major left hemisphere's language areas. But the effects were much stronger for predictive structure building.

While speakers of English seem to adopt a 'wait-and-see' approach, speakers of Dutch are more likely to build sentences in a predictive manner. This means that speakers of different languages differ in how they build grammatical structure during language comprehension.

The researchers next want to apply this method to study other languages, as well as the role of different linguistic properties. "Now that we know that we can use this method to study how people build grammatical structure during naturalistic spoken language comprehension, we can see how this process is influenced by other linguistic properties. In future work, we will investigate how the brain might use the prosodic properties of speech to extract the grammatical structure of spoken sentences," says Coopmans.