"Learning and practicing something, for instance a second language, strengthens the brain," said Ping Li, professor of psychology, linguistics, and information sciences and technology at Pennsylvania State University. "Like physical exercise, the more you use specific areas of your brain, the more it grows and gets stronger."
The study followed 39 native English speakers' brains over a six-week period as half of the participants learned Chinese vocabulary. Of the subjects learning the new vocabulary, those who were more successful in attaining the information showed a more connected brain network than both the less successful participants and those who did not learn the new vocabulary.
The researchers also found that the participants who were successful learners had a more connected network than the other participants even before learning took place. A better-integrated brain network is more flexible and efficient, making the task of learning a new language easier.
The efficiency of brain networks was defined by the researchers in terms of the strength and direction of connections, or edges, between brain regions of interest, or nodes. The stronger the edges going from one node to the next, the faster the nodes can work together, and the more efficient the network.
Participants each underwent two fMRI scans -- one before the experiment began and one after -- in order for the researchers to track neural changes. At the end of the study period, the researchers found that the brains of the successful learners had undergone functional changes -- the brain network was better integrated.
Such changes, the researchers suggested after reviewing a number of related studies, are consistent with anatomical changes that can occur in the brain as a result of learning a second language, no matter the age of the learner, as they reported in a recent issue of Cortex.
"A very interesting finding is that, contrary to previous studies, the brain is much more plastic than we thought," said Li,. "We can still see anatomical changes in the brain [in the elderly], which is very encouraging news for aging. And learning a new language can help lead to more graceful aging."
Meanwhile, the team has begun working on interactive ways to teach language using virtual 3-D-like environments with situation-based learning to help the brain make some of those new connections more effectively. Such studies hold the promise that the process of learning a second language as an adult can in fact lead to both behavioral and physical changes that may approximate the patterns of learning a language as a child.
Yang, J., et al., Neural changes underlying successful second language word learning: An fMRI study, Journal of Neurolinguistics (2014), http://dx.doi.org/10.1016/j.jneuroling.2014.09.004