How does speaking a dialect influence the brain?
One of the most important skills for successful development of youth into productive members of society is knowing how to read and spell. Although quintessential, literacy acquisition is also a highly complex and (time-) demanding process. Different form learning how to speak, which happens innately by learning statistical properties of one’s native language through exposure, reading and spelling have to be actively learned and trained.
Some children speak a different language at home compared to the one used in school. These children either stem from a bilingual language background or have recently moved to a place where they do not (yet fully) speak the language. Alternatively, the language used in colloquial speech is very different from its standardized language form used in formal and instructional settings.
My previous research has examined how speaking the colloquial German dialect of Swiss German impacts pre-school language processing in the brain, and, how this relates to the familiarity with the standard language used for reading and spelling learning in school. In the German-speaking part of Switzerland the general language used in school is the Swiss Version of Standard German, which differs from Swiss German greatly in terms of pronunciation, grammar structure and vocabulary.
Dialect and Standard language are processed differently
Using the method of Electroencephalography (EEG), we examined how familiarity with dialect-specific pronunciation and vocabulary of spoken words impacted speech sound and semantic processing in the brains of kindergarten-aged children, before entering school. Specifically, we examined children who either grew up speaking Swiss German dialect with little exposure to Standard German or were raised in Standard German-speaking households.
Our study showed that Kindergarten-aged children hold a strongly primed inventory for native speech sounds, as found in pronunciations, and required more extensive mechanisms to process non-native (and thus more unfamiliar) variants than native ones. Moreover, children showed a semantic mismatch effect in the brain for non-native word names (e.g., Swiss German “Rüebli” vs. Standard German “Karrotte” for the word carrot), when they were presented with the corresponding image. A semantic mismatch effect is an automatic process which occurs when e.g., a spoken word is simultaneously compared with an image, and then is checked for whether this pair matches with the hearer’s expectation. This brain response pattern we received for Standard German vocabulary in Swiss German native children seem to show that they likely have not (yet) formed robust mental representations of Standard German vocabulary before they enter into Grade 1 of elementary school.
Speaking a dialect makes learning to read and spell more complicated
We further tested how speaking Swiss German dialect (and other variables) impacted reading and spelling learning after one year of formal instruction in school. When we just looked at how well Swiss German and Standard German native children scored in standardized reading and spelling tests, we did not find any notable differences. However, when we ran an analysis accounting for pre-school literacy-related skills (e.g. letter knowledge, letter-to-sound matching, etc.) collected in Kindergarten which have been shown to predict reading and spelling outcome in school, we could see that speaking Swiss German dialect negatively impacted Grade 1 reading and spelling. What does this mean? As Swiss German speaking children are less able to work with speech-to-print matching strategies during early reading and spelling due to Swiss German vs. Standard German pronunciation differences, and at the same time also need to learn which Swiss German words correspond to the Standard German ones, they encounter some additional difficulties in the literacy learning process than Standard German speaking children. However, the fairly high developed pre-school literacy-related skills we found in Swiss German speaking children seem to counteract these problems, at least to some extent. Similarly, previous studies with bilingual children have shown that growing up with two different languages may increase the ability to analyze and think about language and thus heighten meta-linguistic skills. Strong abilities in such skills can make it easier to learn some aspects of reading and spelling and may even help compensate disadvantages.
Use story time to actively point out differences
As a recommendation for parents with dialect-speaking children, I suggest that, if they like, they can playfully introduce their child to dialect vs. standard language differences from already rather early on (shortly before or during kindergarten) and actively explain which words spoken in dialect match the ones of the standard language. This can easily be done during storytelling by sometimes reading a story in the standard language and actively involving the child by asking (story- and/or vocabulary-related) questions in dialect. One can even frame such a parent-child interaction as a game and say, “Let’s read a story in the way that they talk on television” (for the standard language) or “Let’s read a story in the way that Grandma would tell it” (for dialect).
The next step in my research is to combine brain and behavioral measurements for language processing with literacy outcome in dialect-speaking children.