Memory limits give rise to open-ended language abilities

January 26, 2017
Credit: CC0 Public Domain

A hallmark of human language is our ability to produce and understand an infinite number of different sentences. This unique open-ended productivity is normally explained in terms of "structural reuse"; sentences are constructed from reusable parts such as phrases. But how languages come to be composed of reusable parts in the first place is a question that has long puzzled researchers in the language sciences.

A study published in PLoS ONE led by Cornell psychology professor Morten H. Christiansen provides new insight into this age-old question by simulating in the lab. The results demonstrate how basic limitations on how we remember sequences can give rise to a language-like system of reusable structural patterns, when amplified across generations of learners.

Christiansen and colleagues used human learners to simulate cultural evolution through a process of "iterated learning." Inspired by the classic game of telephone, the study involved taking the output from one participant and using it as the input for the next one, and so on for a total of 10 "generations" of learners. Sitting in front of a computer, each participant was exposed to a set of consonant strings under the guise of a memory experiment and then subsequently asked to recall them. The recalled strings then became the set of strings that the next participant had to learn.

Whereas the initial set of strings seen by the first participants contained no reusable structure, the repeated cycle of memorization and recall resulted in increased structural reuse.

"Our subsequent statistical comparisons with linguistic corpora revealed that the patterns of reuse observed in the final generation of learners were similar to what is observed in natural language," said Christiansen. "This suggests that basic cognitive limitations on how we learn sequences can lead to the emergence of a language-like system of reusable structural patterns."

The results of the study by Christiansen and colleagues speak to the long-standing debate over the fundamental nature of our linguistic abilities and how they evolved in our species. If basic limitations on memory can explain the emergence of structural reuse in , then it suggests that at least this aspect of human language may not require specific biological adaptations. Instead, it highlights the importance of cultural transmission in the evolution of language, as already noted by Charles Darwin in "The Descent of Man."

Explore further: 'Now-or-never bottleneck' explains language acquisition

More information: Hannah Cornish et al. Sequence Memory Constraints Give Rise to Language-Like Structure through Iterated Learning, PLOS ONE (2017). DOI: 10.1371/journal.pone.0168532

Related Stories

'Now-or-never bottleneck' explains language acquisition

June 8, 2016
We are constantly bombarded with linguistic input, but our brains are unable to remember long strings of linguistic information. How does the brain make sense of this ongoing deluge of sound?

Language use is simpler than previously thought

September 21, 2012
(—For more than 50 years, language scientists have assumed that sentence structure is fundamentally hierarchical, made up of small parts in turn made of smaller parts, like Russian nesting dolls.

Study: Word sounds contain clues for language learners

September 13, 2011
( -- Why do words sound the way they do? For over a century, it has been a central tenet of linguistic theory that there is a completely arbitrary relationship between how a word sounds and what it means.

Recommended for you

Gene associated with schizophrenia risk regulates neurodevelopment

September 25, 2017
A gene associated with the risk of schizophrenia regulates critical components of early brain development, according to a new study led by researchers from Penn State University. The gene is involved in the translation of ...

For a better 'I,' there needs to be a supportive 'we'

September 25, 2017
If you're one of those lucky individuals with high motivation and who actively pursues personal growth goals, thank your family and friends who support you.

Child abuse affects brain wiring

September 25, 2017
Researchers from the McGill Group for Suicide Studies, based at the Douglas Mental Health University Institute and McGill University's Department of Psychiatry, have just published research in the American Journal of Psychiatry ...

Babies can learn that hard work pays off

September 21, 2017
If at first you don't succeed, try, try again. A new study from MIT reveals that babies as young as 15 months can learn to follow this advice. The researchers found that babies who watched an adult struggle at two different ...

Study links brain inflammation to suicidal thinking in depression

September 21, 2017
Patients with major depressive disorder (MDD) have increased brain levels of a marker of microglial activation, a sign of inflammation, according to a new study in Biological Psychiatry by researchers at the University of ...

Oxytocin turns up the volume of your social environment

September 20, 2017
Before you shop for the "cuddle" hormone oxytocin to relieve stress and enhance your social life, read this: a new study from the University of California, Davis, suggests that sometimes, blocking the action of oxytocin in ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.