Neuromuscular Plasticity

     Some researchers believe that the loss of neuromuscular plasticity that occurs around puberty can account for the apparent inability to achieve native-like pronunciation of a second language if beginning in adulthood. Plasticity in this case, refers to the flexibility of the muscles and their ability to do motions that they have never done before. The oral production of any language involves the perfect coordination of hundreds of speech muscles. Like some extremely complicated dance or sport, it could take decades of dedicated effort to accomplish a professional level of skill. Furthermore, despite endless practice some might never master it at all. Pronunciation of a second language, like any complicated dance or sport, is easier to master if the learner begins learning before childhood. Most Olympic sportspersons for example, started learning their sport well before puberty. Just like children’s regular muscles, children’s speech muscles also have more plasticity than adult’s. In other words, they are simply more flexible and can adapt to new movements more freely. Adult’s speech muscles, on the other hand, are more rigid and less able to adapt to unfamiliar motions. In fact, it could be said that they are stuck in the motions of their first language, and therefore, unable to do the motions necessary for the second language. This could explain why adults seemingly never achieve native-like pronunciation while children generally do.