Department of Cognitive and Behavioral Science
University of Tokyo, Komaba
Sakai: It depends,
because there may not be one single mechanism for lifelong learning. I
think that language acquisition is unique compared with other learning
skills. Although we can learn any language after puberty, but its
performance is quite different from one's own native language that is
special throughout life. There are issues regarding learning English
earlier for non-native English children. For example in Japan, the
Ministry is trying to promote English conversation lessons even in
elementary schools, on the assumption that "earlier is better". However,
learning conversation like "How are you?" - "Fine, thank you. And you?" is
just a phrase association. That skill may be based on general associative
mechanisms, but it could be radically different from language acquisition,
because there are no syntactic structures in such a kind of learning. For
successful life-long learning, I think that the use of native language for
logical thinking is far more important than hastily learning other
languages during the early years.
Sakai: There is a classic study by Johnson
and Newport, which shows that at certain times in life there may be an
important condition - called a critical period - for determining second
language performance. The subjects, Chinese and Korean born residences of
the United States, were grouped according to their age when they moved to
the US. Those who came to the States between three to seven years old had
language performance more like a native than others. But after that,
individual differences become very significant, and mean scores go down as
the age of arrival increases. One might argue that the human brain
function sets earlier in life and that ability to adapt to a new
environment - a new language environment - is somehow lost. However, this
process may depend more on the people's motivation and capability later in
life, even if age-related factors appear to play a critical role early on.
There is another classic proposal by Lenneberg about first language
acquisition. The clinical observation suggests that people with some
lesions in the left brain recover quickly from language disorders before
puberty, but after that, adults tend to experience more difficulty in
recovering. This means that until puberty the brain has more flexible
plasticity to cope with acquired lesions. It also suggests a limited
capacity for entire lifelong learning, but we are not sure how far we can
exploit our own capabilities.
Sakai: I think so, yes. It also depends
on what you learn. As for language, I think that Pat Kuhl has shown quite
clearly that the brain is an automatic language-learning machine. The
infants can quickly pick up various sound parameters of a native language.
It is achieved in a very interesting and special manner, because it
doesn't require any conscious effort or explicit knowledge. I think this
language process represents a unique acquisition mechanism.
Sakai: It is true that emotion, motivation, or
social factors can influence the attitude toward new learning. If you are
not interested in learning something at all, the learning effect would
remain minimal. Emotion and other general environmental factors can affect
learning, but it's very difficult to prove it scientifically. Even when
genetic and environmental factors are similar, like identical twins, you
cannot completely control learner's motivation. Even if you are presented
with the same task, the internal conditions of individuals are so
different that the learning experience can become different, too.
Sakai: We have to consider not only human rights but also
ethical issues for any experimental approaches for learning or education.
For example, suppose that you design an interesting training program that
requires a blind control group. Now, let's suppose that the training
works. Once the training results are known to the subjects, the trained
person may be very happy, but the control remains unstatisfied and wants
the benefit from the training. This will create an ethical problem. It
would be ideal to provide equal opportunities for both groups, such that
the previous control group become the trained group in the next session.
We should always keep considering benefits for every valued subjects.