Pint of Science Edinburgh 2017: Language, the brain and dementia

The brain is a complex and mysterious entity. We desperately try to make sense of it by mapping its regions and dividing hemispheres into functional units. Yet, the distinct divisions remain elusive, measurements are approximations and “right-left” specialisation is closer to myth than reality. A Pint of Science evening dedicated to the brain aimed not to dissect and measure the brain with a ruler, but to celebrate its unique and enigmatic nature and the wonders the brain offers us.


Part I. What’s left of, and right about, the asymmetric brain?

Probably the most pervasive idea associated with the brain is that it has two hemispheres that are dramatically different, and people somehow prefer to use one of them. It makes them either artists (if they happen to use the right hemisphere) or scientists (if they use the left one). Lewis Hou, a neuroscientist and science enthusiast from the University of Edinburgh, acknowledges that, strictly speaking, this is not untrue. Asymmetries do exist, and humans have more of them than, say, chimpanzees. And perhaps they are the reason for the myriad of traits that grant humans their unique abilities.

Back in the day, the great physicist Albert Einstein, during a casual chat in a pub, mentioned it was okay to dissect his brain after his death. Luckily, it didn’t meet any ethical hurdles back then and scientists were able to learn some valuable lessons from Einstein’s brain anatomy. Some of the information gleaned related to the area responsible for motions, particularly hand movement. As we know, Einstein was a keen violinist. Hence, it was not surprising that his right hemisphere had a pronounced curve termed “hand knob” (British scientists, not being able to tolerate the name, suggested “omega sign” instead). Interestingly, its presence does not just depend on the ability to play music, but also on which instrument you play. It turned out that pianists have two hand knobs – one on either hemisphere. Not only does it depend on an instrument, but also on the age at which a person started playing. People who learned to play an instrument before the age of nine had more pronounced hand knob than people who learned to play later on. This, nevertheless, is nowhere near the conclusion that we preferentially use either left or right hemisphere. However, the UK teachers survey showed that 91% of teachers believe that differences in hemisphere dominance explain personal differences.

The take home message here is that, indeed, there are certain differences between the brain’s hemispheres (such as an asymmetrical hand knob in some cases). These are essential functional asymmetries – intriguingly, there are suggestions that increased symmetry is a trait of schizophrenia. But overall, the differences are subtle and nuanced. As Lewis suggested: “You can’t be anymore left- or right-brained than you can be left- or right-hearted”.


Part II. Monolingualism: a treatable disease of the civilisation?  

A group of people in Aboriginal Australia are approaching a river, whilst speaking a language. Once crossed the river, they immediately switch to a different language. The reason for this is that many Australian tribes believe that language belongs to the land. This is not surprising, explained Dr Thomas Bak, whose research is dedicated to language and cognitive functions. Today, linguists share an idea that the human language developed in a highly multilingual context. It is natural for us to speak a variety of languages, as much as it is natural for us to move around instead of leading a sedentary lifestyle. It is the healthiest diet for our brains.

In aboriginal Australia, people speak at least three languages (and can be up to sixteen). Moreover, the local communities have a rule of linguistic exogamy – marrying someone who speaks the same language is a taboo and considered incestuous, since the tribes are quite small. Thus, multilingualism can be considered a default state for the human brain, with monolingualism arriving later on, along with other developments of civilisation.  

So, what is remarkable about bi- or multilingualism? One of its most important traits is that it teaches us to understand social situations better. Indeed, being able to speak different languages involves a constant process of activation of one language and suppression of the others, depending on a social situation. It’s a continuous exercise and not a trivial task. As a result, people who know more than one language show better performance in executive functions, social cognition and linguistic abilities in general. For instance, Dr Bak mentioned an experiment that showed that people who speak more than one language were better at commanding their native language.

Knowing another language is also beneficial in older age. Bilingual people were shown to be more resistant to dementia and recovered from a stroke much quicker. A week’s intensive language course improves attention level, even in people of 78 years of age. And you don’t need to be bilingual from childhood. Performing a foreign language exercise is like a normal exercise – it’s about practice rather than passive storage of language.

Interestingly, when asked whether it is more beneficial to your cognitive function to know a similar language to your native one or a completely different language, Dr Bak replied that this is still under debate. Knowing a completely different language requires a very different circuitry and engages different brain areas. This is not the case with similar languages. However, similar languages may be beneficial because there is a higher demand for suppression and active work, since the languages have so much in common. Arabic and English can sit in different parts of the brain and never overlap, but French and English would require a complex control system to activate one and suppress the other. Nevertheless, whatever foreign language you speak, make sure to do it regularly. Like with a balanced diet and physical exercise, mental exercise requires a healthy routine, and the ample benefits will not take long to show.  


This article was written by Alina Gukova and edited by Bonnie Nicholson.

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