“Hans” is also still learning, but unlike “Hänschen”: Scientists have discovered how the brains of adults change when they learn a new language. Accordingly, new nerve connections form in and between the areas that normally process language. Learning a foreign language is also supported by brain regions in the right hemisphere that are not otherwise responsible for language. Learning a native language is neurologically different from learning a second language.
Our brain changes as we grow and continues to adapt to new mental challenges. Among other things, new neural connections form when we learn our native language or a second language at a young age, as previous studies show. But how adaptable is our brain in adulthood when we learn a new foreign language? There are various models for this, but so far there has been little direct research.
What happens in the brain when learning German?
A team led by Xuehu Wei from the Max Planck Institute (MPI) for Cognitive and Neuroscience in Leipzig has now researched this question in more detail. To do this, the researchers organized a six-month intensive course in which 51 native Arabic speakers who had fled Syria learned the German language. The test subjects had no prior knowledge of German and did not speak any other second language; the aim was language level B1. Using high-resolution magnetic resonance imaging (MRI), the scientists took three brain scans of each of the young participants - at the beginning, in the middle and at the end of the language course - and evaluated them. In particular, the researchers observed how the different areas of the brain connected to each other when learning a foreign language. They compared these changes with the respective learning progress of the test subjects, which was determined using standard language tests from the Goethe Institute.
The result: Within the areas of the so-called language network in the left hemisphere of the brain, the nerve connections strengthened as a result of language learning. In addition, additional regions in the right hemisphere were active while the test subjects were learning German, as the MRI images showed. New nerve connections emerged there too. “The connectivity between language areas increased in both hemispheres as learning progressed,” reports Wei. “Learning new words strengthens the lexical and phonological subnetworks in both hemispheres, especially in the second half of the learning phase.” Accordingly, when learning a language, the neural connections between the brain regions that are needed to process language meaning and pronunciation change. The brain thus adapts to the new cognitive requirements. This enables learners to communicate and think in the new language, as Wei and her colleagues report.
The left hemisphere of the brain allows the right hemisphere to work
Interestingly, the functional connections between the two hemispheres of the brain decreased during language learning, the brain scans revealed. The scientists conclude that the language-dominant left hemisphere inhibits the right hemisphere to a lesser extent when learning a second language than when learning the native language. This would likely free up additional resources in the right hemisphere of the brain to learn the new language. “This underlines the importance of neuroplastic adaptations of the network for processing the newly learned language and the use of regions in the right hemisphere of the brain that were not previously used for language processing,” says senior author Alfred Anwander from the Leipzig MPI.
The language course helped the people from Syria to learn German, to arrive better in Germany and to become part of society. From a scientific perspective, the study improves understanding of how first and second languages are learned and processed in the brain.
Source: Xuehu Wei (Max Planck Institute for Cognitive and Brain Sciences) et al., Proceedings of the National Academy of Sciences (PNAS), doi: 10.1073/pnas.2306286121