Native languages may shape how our brains are wired
- Although certain core brain regions are involved in the processing of all languages, these regions show distinct activation patterns during the processing of different languages.
- The different brain activation patterns observed during the processing of specific languages suggest that individuals with different native languages would show structural differences in the brain.
- A new study found that native Arabic and German speakers showed differences in the wiring of brain regions involved in the processing of language.
- These findings suggest that learning one’s native language during childhood shapes the connections in the brain and may explain why differences in native languages affect how people think.
An individual’s native language can shape how they think. For instance, while there is a single word for colors in the blue spectrum in English, there are two distinct words in Russian that distinguish between light and dark blue.
Interestingly, native Russian speakers tend to be much faster in tests involving the discrimination of light and dark blue than native English speakers. Similarly, results have also been observed for the words used to describe directions in different native languages and the sense of orientation an individual has.
A recent study published in NeuroImageprovides evidence for differences in the wiring of language processing regions in the brain of native Arabic and German speakers.
This suggests that learning one’s native language during childhood could lead to structural changes in the brain, potentially explaining the differences in cognitive function in individuals who speak different first languages.
Language processing in the brain
Scientists have, over the years, shown that language is processed and produced by a complex network of interconnected brain regions, predominantly in the left half or hemisphere of the brain. Moreover, studies have revealed that distinct brain pathways are associated with processing particular aspects of language, including semantics (meaning of words), syntax (grammatical structure), and phonology (sounds associated with language).
The processing of syntactic and semantic information primarily occurs in brain regions located in the left hemisphere. However, other information associated with language, especially that concerning the sounds and intonation, is processed in either the right or both hemispheres. This information is then integrated with the semantic and syntactic information processed in the left hemisphere.
There are nearly 7,000 different languages that are used across the globe. Although the same core brain regions are involved in the comprehension and production of all languages, individuals with different native languages show divergent brain activation patterns during language processing. These distinct patterns of activation of brain regions are due to the differences in the syntactic, semantic, and phonological features of these languages.
Studies have found structural differences in the brains of individuals with different native languages. This suggests that the acquisition of one’s native language during childhood induces changes in the structure of the brain that differ from those who have a different first language.
The tissue in the brain can be classified as either gray or white matter. The gray matter is composed of the cell bodies of nerve cells or neurons and is involved in information processing. On the other hand, white matter consists of neuronal processes, i.e. axons and dendrites, that conduct information from one neuron to the other.
A previous study revealed that English and Chinese speakers show differences in the density of gray and white matter in areas involved in language processing. Similarly, studies have also shown differences in the patterns of white matter tracts that connect brain regions in native English, German, and Chinese speakers.
Arabic vs. German: Differences in brain connectivity
In the present study, the researchers compared the differences in the wiring of brain regions involved in language processing in individuals with Arabic and German as their native languages. The researchers chose these languages due to the stark difference in the role of semantics and syntax.
Firstly, these languages belong to different families, with Arabic being a Semitic language and German being an Indo-German language. German has a more complex grammatical or syntactic structure than Arabic, whereas Arabic is semantically more pronounced.
Unlike German, Arabic words often omit short vowels, and the meaning and pronunciation of Arabic words are based on context. Furthermore, Arabic script is written and read from right to left, whereas German script is written from left to right.
Consistent with this, studies have shown greater activation of regions involved in syntactic processing during comprehension of German. In contrast, others have shown greater involvement of regions involved in semantic processing during comprehension of Arabic. These studies involve examining brain patterns using magnetic resonance imaging (MRI) while the participants process a particular language.
Connections in the left and right hemispheres
In the present study, the researchers examined whether native German and Arabic speakers showed structural differences in their brains at baseline owing to the different demands on the brains during the processing of these languages.
Specifically, the researchers examined whether native German and Arabic speakers showed differences in the patterns of connection in the brain at baseline. They used a type of MRI, called diffusion-weighted MRI, to detect white matter tracts that connect different regions of the brain.
Participants in both groups showed greater connectivity in the left hemisphere, where the processing of language in general predominantly occurs. However, participants with German as their native language showed stronger connections between brain regions involved in language processing within each hemisphere compared with Arabic speakers.
In contrast, native Arabic speakers showed stronger connections between regions in the left and right hemispheres than native German speakers. The greater activation of both hemispheres could be due to the semantic complexity of Arabic and the right-to-left writing system.
In addition, brain scans of German speakers revealed stronger connections between brain regions involved in syntactic processing in the left hemisphere. In contrast, connections between regions associated with semantic processing were stronger in native Arabic speakers.
Can language change personality?
In sum, the present study shows that speaking one’s native language over a lifetime results in changes in the brain’s structure.
The study’s author Dr. Alfred Anwander, a neuropsychologist at Max Planck Institute, said:
“The study strongly supports the environmental and native language dependence on developmental shaping of the brain and in particular the shaping of the connections which directly influence our cognitive processing in the brains. This might point in the direction that also individual personality is not ‘hard-wired’ in our brains and is the result of lifelong experience.”
Dr. Anwander also suggested that the study results could be used to tailor approaches for individuals with neurological diseases.
“In particular, our childhood, where the brain still shows a stronger possibility of adaptation, might leave important traces in our brains and build the basis for the specialization of every individual brain. Besides the better understanding of the different processing of the different languages in the brain, this might have also some implication in clinical cases where individualized treatment might be needed e.g. in neurological rehabilitation strategies.”
— Dr. Alfred Anwander, study author
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