Hot on the trail of language processing

Text: Trio MedienService Bonn

Getting at the very core of language and understanding how people process it – this is what fascinates Harald Clahsen. And the core is grammar, the system of rules that constitutes our communication and differentiates us from all other species. Psycholinguist Harald Clahsen has made an international name for himself researching into language acquisition and language processing. He combines various methods to track down a competence that is both shaping our world and challenging society: multilingualism.

Centres of research into multilingualism can be found in Canada, the United States, the United Kingdom, Australia and Switzerland – the places where people have always spoken a lot of different languages. In Germany, by contrast, multilingualism is far from being taken for granted by society or academia, even though it has long become a fact of life at German schools and kindergartens. “Taking a global view, monolingual individuals tend to be the exception nowadays; the rule is that people speak two languages or more,” says Harald Clahsen. Together with his wife, linguist Claudia Felser, he is about to establish the new Potsdam Research Institute of Multilingualism at the University of Potsdam, closing a gap in German research. Harald Clahsen is the first Humboldt Professor to work in one of the new Federal States. “The location is ideal: Berlin, with its multilingual environment and resulting need for research and consultancy, is right on the doorstep,” he explains.

Monitoring multilingualism

Harald Clahsen and his team want to investigate the representation and effects of multilingualism in the human brain, and for this he uses various methods. He is less interested in the ‘where’ than in the ‘how’. “I’d like to observe people processing language while it is actually taking place.” This is why the top researcher prefers electroencephalography (EEG) to imaging procedures which usually involve a time lag of one or two seconds in producing pictures of active areas of the brain.

EEG is an established neurological method that measures variations in the elec-trical signals on the scalp and records them on an encephalograph. These variations tell us a lot about physiological processes in brain cells – not least with regard to language processing. “We give probands a number of active and passive sentences. Processing this information only takes milliseconds, and the EEG records the brain waves like a seismograph. One of the results of these measurements is that people have to use more energy for the passive sentence than for the active construction,” the linguist concludes.

EEG will also help him to answer other questions. “I would like to know more about the various aspects of language, such as whether meaning, grammar and phonetic information are processed one after the other or all at the same time.” In Potsdam, Clahsen intends to extend the scope of these experiments to multilingualism. One question will be: Does the processing of linguistic form and meaning function the same way in the second language as it does in the first?

A cocktail of methods for a complex picture

As a professor for the psycholinguistics of multilingualism, Harald Clahsen will investigate two clearly defined linguistic fields: the grammar of words and the grammar of sentences. Words themselves can, after all, be complex: they are composed of several parts and are processed differently. For this purpose, Clahsen and his team will amalgamate several methods – a promising undertaking. “I combine behavioural tests, which we use for determining reaction time for certain tasks, with eye movement experiments and EEG measurements to get as complex a picture as possible,” he says, explaining his approach which fuses linguistic theory with psycholinguistic and neurolinguistic aspects.

The Humboldt Professor wants to discover which words people find difficult to process and which tend to be easy. So far, he has conducted his tests with monolingual individuals or those who only learned a foreign language at a later stage. In Potsdam, it will be bilingual children sitting in front of the screen. When it comes to testing younger children and comparing them with other age groups, letters do not sufice. “If probands can’t read yet, they are played sentences and shown images at the same time. We can observe where they look first when they hear a reflexive sentence, for example, and can infer whether they have understood it correctly.” Here, too, the Humboldt Professor focuses on the processing of grammatically structures.

Language consultancy

Harald Clahsen will combine this basic research at the Potsdam multilingualism centre with practical consul-tancy for three speci餀 c target groups: parents who are bringing up their children bilingually, teachers of foreign languages and teachers who work together with multilingual children. “Deficits in German are often classified as a language disorder, and children are taken out of mainstream schooling,” Harald Clahsen reports. He would like to draw up criteria so that prac-titioners can use mistakes to determine whether they are actually dealing with a language disorder.

Clahsen is enthusiastic about his research field of language: “With a reasonable quantity of rules and our vocabulary we can make an infinite number of combinations and express what we want. This is a seminal aspect of being human.”