Following the civil war in Syria, Europe has granted asylum to thousands of refugees in 2015 and 2016. Teaching the local language to the newly arrived is an important key element to achieve a successful integration. As many refugees are adults and language learning does not come as easy as to a young child, recent research attempts to inform us about the differences between children and adult learners and translate this research into teaching approaches that address these differences.
How to learn “Alienese”?
Language represents a cultural world view and is therefore not only a necessary skill to efficiently communicate with people from another country, but also the most important prerequisite to achieve a full integration into a foreign culture and its social context. For that reason, researchers at the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig and the Herder Institute at the University of Leipzig are trying to figure out whether a methodology that focusses on German grammar and syntax or one that focusses on vocabulary, semantics and communication leads to a better learning progress in adults from Syria. Through magnetic resonance imaging the neuroscientists are studying how learning a new language changes the brain of ninety Syrian learners that have no previous knowledge of German and how particular teaching methods can influence brain structure over a six-month language course.
Why should one of these two teaching approaches be more effective for second language acquisition in adults? As considered by implicit learning theory, processing of a sentence is facilitated when a preceding sentence has the same syntactic form, a mechanism called syntactic priming. Syntactic priming is a mechanism for language learning because the repetition of syntactic structures helps in mapping meaning onto form. This has also been shown by researchers of the Max Planck Institute for Psycholinguistics in Nijmegen in the Netherlands by combining a miniature language (a language purposely constructed by linguists and psychologists that contains a set of patterns and rules), with a syntactic priming paradigm. In the experiment, participants had to learn a new language called “Alienese” and during this process structural and functional MRI data was acquired. In the experimental paradigm, participants had to comprehend the new language by associating sentences with corresponding scenes that were presented on images. In two conditions, the researchers used word orders that were not permissible for the native language of the participants (in this case Dutch; The not permissible word orders were verb-object-subject and object-subject-verb) and two other conditions in which the word order corresponded to the by the participants´ well known “active” word order (subject-verb-object and subject-verb). While being scanned, the participants who had previously learned the miniature language had to read upcoming sentences in the new language and match the corresponding pictures with scenes that represented their meaning. The results of the study revealed differences in activation in regions known to be involved in syntactic processing. The repetition of a known type of structure led to a repetition suppression effect, which means a decrease in neural activation compared to baseline (the baseline condition serves as a comparison which allows to detect signal changes associated with a specific mental activity). On the contrary, the repetition of the infrequent novel structure led to repetition enhancement, an increased neural response to the stimuli. The repetition suppression effect observed when presenting the new language using a familiar word order, can be related to similar effects that have been observed for syntactic repetition in studies using natural language. These observations suggest that the known structure in the new language had been mapped onto its´ native counterpart and therefore it is possible that a newly acquired language appears to be integrated in the same neural structures as the native language. As the repetition of unfamiliar structures led to repetition enhancement, the researchers suggest that repetition enhancement effects are related to the building of new representations for these novel word orders in the brain and therefore reflect the learning process. On the other hand, repetition suppression effects had also been observed in brain regions linked to lexical and semantic processing in the first language as well as during language learning. Therefore, repetition suppression effects might reflect the gradual strengthening of a lexical-semantic mapping that is present in both first and second language learning.
Does language learning in adults and children recruit the same brain regions?
Angela D. Friederici investigates the different processes involved in language learning and describes three different mechanisms for grammatical sequence learning. The first one consists of extracting regularities from what we hear and memorizing these for further use. This early phonology based language learning would be dependent on an input-to-output-circuit which is present in vocal learning animals, for example songbirds. In humans, this auditory to motor mapping potentially relies on the dorsal fiber bundle that connects the sensory auditory cortex with the premotor cortex and thus can be viewed as a candidate for an auditory-to-motor circuit underlying early phonology-based language learning. A second process involves learning adjacent dependencies between A and B, for example a noun and its determiner, by using the same mechanism as described before. A third and more complex mechanism is the processing of multi-level hierarchically structured sentences, a mechanism that could be achieved through binding two elements into a minimal hierarchical structure as proposed by Noam Chomsky. Especially the German language allows the construction of sentences with multiple embeddings in the form of subject–verb dependencies, as for example in “Peter wusste, dass Maria, die Hans, der gut aussah, liebte, Johann geküsst hatte” (“Peter knew that Maria who loved Hans who was good looking kissed Johann”). A mechanism that processes such complex grammatical structures would require a computational system that goes beyond those mechanisms that underlie early phonology based language learning and the extracting and memorizing of regularities. Friederici proposes that such a complex mechanism could be based on the part of the dorsal pathway that connects the temporal cortex to Broca´s area and that is not present at birth and still not fully matured in children at the age of seven. The fact that this part of the dorsal pathway is not fully developed in infants supports the idea that it is functionally distinct and that it might be involved in the processing of multi-level hierarchically structured sentences. If the early phonology based learning mechanism based on extracting and memorizing of regularities relies on functionally different brain areas than the processing of complex grammatical structures, then each mechanism would be enhanced by different learning teaching methodologies.
To wrap it all up
Second language learning is a very difficult task, as it requires not only memorizing new vocabulary, but also putting these new words together in a grammatically correct way and integrating them with pre-existing knowledge. During this process, it seems to have an influence on the learner´s progress whether the second language resembles the grammatical properties of the learner´s native language. Studies have shown that in subjects that had learned an artificial language with real structures that resembled the grammatical structure of their mother tongue, brain activation decreased within regions of the brain network known to be involved in their native language processing whereas increased in these regions when subjects were faced with unfamiliar word orders. A possible explanation for this observation could be that the increased activity when facing unfamiliar word orders during the process of learning a new language, might reflect the building and strengthening of a neural network that processes novel word order regularities. On the flipside, a decrease in activation during learning the new language might reflect the integration of the novel language structure into the same brain areas that are engaged in the processing of the native language. The questions of whether the same or different brain areas are recruited during first and second language acquisition can give researchers an idea about the effectiveness of methods when teaching a second language to adults. Language is a key factor to achieve a better integration in the social, cultural and professional life and therefore it is a research topic of high social relevance.