[EDLING:890] Adults Can Be Retrained To Learn Second Languages More Easily, Says UCL Scientist

[Francis M Hult]

http://www.sciencedaily.com/releases/2005/06/050615060545.htm

Science Daily

2005-06-15

Adults Can Be Retrained To Learn Second Languages More Easily, Says UCL Scientist

Our ability to hear and understand a second language becomes more and more difficult with 
age, but the adult brain can be retrained to pick up foreign sounds more easily again. 
This finding, reported by Dr Paul Iverson of the UCL Centre for Human Communication, at 
the "Plasticity in Speech Perception 2005" workshop - builds on an important new theory 
that the difficulties we have with learning languages in later life are not biological and 
that, given the right stimulus, the brain can be retrained. 

It is an accepted fact that the younger the child, the easier it is for them to learn a 
second language. Children are able to understand words and hear small sound differences 
that adults often miss -- making understanding more difficult for adults. For example, 
Polish students of English have difficulty differentiating between vowels such as "pen" 
and "pan" while German students must learn to hear a difference between the v in "vest" 
and the w in "west". 

Scientists used to believe that the adult brain could not be retrained later in life to 
distinguish between these sounds: in other words the brain's plasticity (or ability to 
change) was set. 

Dr Iverson shows that adults can retune their brains to hear these differences again. 
Scientists now believe that the difficulties are caused by our experience which teaches us 
to ignore certain sounds so that we are able to give our full attention to the sounds that 
(in our native language) matter most to understanding a sentence. 

Two studies jointly worked on by Dr Paul Iverson and Dr Valerie Hazan, UCL's Department of 
Phonetics and Linguistics, have examined whether it is possible to retune how the brain 
processes speech sounds, and hope that their findings will help make language learning 
easier for adults. In one study, Japanese subjects were retrained to hear the difference 
between r's and l's (something that Japanese students of English tend to find particularly 
difficult). The study tested 63 native Japanese subjects in Japan and London, and had them 
complete a 10-session training course. Before and after training, the subjects were given 
a number of perceptual tests to evaluate their perception of acoustic cues. Similar tests 
were carried out in London on Sinhalese (from Sri Lanka) and German speakers who had lived 
in the UK for more than 20 years. 

In the Japanese training study, the subjects improved their recognition of l's and r's by 
an average of 18%. So, for example, if an individual could identify the difference between 
r and l 60% of the time, at the end of training they would be able to get this correct 78% 
of the time - supporting the view that the brain can be retuned. 

Talking at the UCL workshop, which brings together specialists in language, speech and 
speech perception, Dr Iverson said: "Adult learning does not appear to become difficult 
because of a change in neural plasticity. Rather, we now think that learning becomes hard 
because experience with our first language 'warps' perception. We see things through the 
lens of our native language and that 'warps' the way we see foreign languages. 

"It is very difficult to undo this learning. That is, we change our perception during 
childhood so that it becomes specialized to hear the speech sounds in our first language. 
This specialization can conflict with our ability to learn to distinguish sounds in other 
languages. Through training, we can essentially change our 'perceptual warping' to make 
second-language learning easier. I hope that this research will lead to new ways of 
training adults to learn second languages."