Linguistics as a Window to Understanding the Brain

The ability to communicate through spoken language may be the trait that best sets humans apart from other animals. Last year researchers identified the first gene implicated in the ability to speak. This week, a team shows that the human version of this gene appears to date back no more than 200,000 years–about the time that anatomically modern humans emerged. The authors argue that their findings are consistent with previous speculations that the worldwide expansion of modern humans was driven by the emergence of full-blown language abilities.

The researchers who identified the gene, called FOXP2, showed that FOXP2 mutations cause a wide range of speech and language disabilities (ScienceNOW, 3 October 2002). In collaboration with part of this team, geneticist Svante Pääbo’s group at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, set about tracing the gene’s evolutionary history.

As a uniquely human trait, language has long baffled evolutionary biologists. Not until FOXP2was linked to a genetic disorder that caused problems in forming words could they even begin to study language’s roots in our genes. Soon after that discovery, a team at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, discovered that just two bases, the letters that make up DNA, distinguished the human and chimp versions ofFOXP2. To try to determine how those changes influenced the gene’s function, that group put the human version of the gene in mice. In 2009, they observed that these “humanized” mice produced more frequent and complex alarm calls, suggesting the human mutations may have been involved in the evolution of more complex speech.

When humanized mice and wild mice were put in mazes that engaged both types of learning,the humanized mice mastered the route to the reward faster than their wild counterparts, report Schreiweis, Graybiel, and their colleagues

The results suggest the human version of the FOXP2 gene may enable a quick switch to repetitive learning—an ability that could have helped infants 200,000 years ago better communicate with their parents. Better communication might have increased their odds of survival and enabled the new version of FOXP2 to spread throughout the entire human population, suggests Björn Brembs, a neurobiologist at the University of Regensburg in Germany, who was not involved with the work.

“The findings fit well with what we already knew about FOXP2 but, importantly, bridge the gap between behavioral, genetic, and evolutionary knowledge,” says Dianne Newbury, a geneticist at the Wellcome Trust Centre for Human Genetics in Oxford, U.K., who was not involved with the new research. “They help us to understand how the FOXP2 gene might have been important in the evolution of the human brain and direct us towards neural mechanisms that play a role in speech and language acquisition.”

Chomsky critiqued the field of AI for adopting an approach reminiscent of behaviorism, except in more modern, computationally sophisticated form. Chomsky argued that the field’s heavy use of statistical techniques to pick regularities in masses of data is unlikely to yield the explanatory insight that science ought to offer. For Chomsky, the “new AI” — focused on using statistical learning techniques to better mine and predict data — is unlikely to yield general principles about the nature of intelligent beings or about cognition.

 

Published on Oct 6, 2012

Steven Pinker – Psychologist, Cognitive Scientist, and Linguist at Harvard University

How did humans acquire language? In this lecture, best-selling author Steven Pinker introduces you to linguistics, the evolution of spoken language, and the debate over the existence of an innate universal grammar. He also explores why language is such a fundamental part of social relationships, human biology, and human evolution. Finally, Pinker touches on the wide variety of applications for linguistics, from improving how we teach reading and writing to how we interpret law, politics, and literature.

The Floating University

 

 

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