Brain systems responsible for our ability to learn language

The origins of humans' ability to learn language may be older than our species itself.

New research has found that language may be learned in ancient 'general purpose' brain circuits that emerged before humans existed, and can even be found in other animals, according to Daily Mail.

It’s long been thought that human language relied solely on mechanisms found in our species – but, the new findings now suggest this may not be the case, after all.

In addition to the evolutionary implications, experts say the discovery could be used to help improve language learning for those who may have difficulties, including people with dyslexia and stroke-related damage. 

Researchers analyzed the findings of 16 studies that examined language learning in two systems in the brain: declarative and procedural memory.

 Declarative memory would be used, for example, to memorize a shopping list or remember a person’s face, while the latter would be used to learn a task, such as driving or playing an instrument.

The studies accounted for a total of 665 participants across a number of tasks, including reading, listening, and speaking, in which children were taught their native language, and adults taught a foreign language.

And, the researchers found what they say are ‘robust and reliable’ links between language and these ancient evolutionary brain systems.

‘Our conclusion that language is learned in such ancient general-purpose systems contrasts with the long-standing theory that language depends on innately-specified language modules found only in humans,’ said the study’s lead investigator, Michael T Ullman, PhD, professor of neuroscience.

‘These brain systems are also found in animals – for example, rats use them when they learn to navigate a maze,’ said co-author Philip Hamrick, PhD.

 ‘Whatever changes these systems might have undergone to support language, the fact that they play an important role in this critical human ability is quite remarkable.’

According to the researchers, the ability to remember words of a particular language is linked to the ability to learn using declarative memory.

Grammar abilities, on the other hand, were linked to procedural memory in children learning their native language.

For adults, learning a foreign language first correlated with declarative memory, before later moving on to procedural memory.

The phenomenon was seen consistently across several languages, including English, French, Finnish, and Japanese

The researchers say the findings have broad implications.

‘Researchers still know very little about the genetic and biological bases of language learning, and the new findings may lead to advances in these areas,’ said Ullman.

‘We know much more about the genetics and biology of the brain systems than about these same aspects of language learning.

‘Since our results suggest that language learning depends on the brain systems, the genetics, biology, and learning mechanisms of these systems may very well also hold for language.’

Better understanding the role of these systems in our ability to learn language could be used to help people with aphasia, dyslexia, and autism, the researchers note.

‘We hope and believe that this study will lead to exciting advances in our understanding of language,’ Ullman says, ‘and in how both second language learning and language problems can be improved.’

N.H.Kh