T E X T
SPEAKING two languages rather than just
one has obvious practical benefits in an
increasingly globalized world. But in recent years,
scientists have begun to show that the advantages
of bilingualism are even more fundamental than
being able to converse with a wider range of
people. Being bilingual, it turns out, makes you
smarter. It can have a profound effect on your
brain, improving cognitive skills not related to
language and even shielding against dementia in
old age.
This view of bilingualism is remarkably
different from the understanding of bilingualism
through much of the 20th century. Researchers,
educators and policy makers long considered a
second language to be an interference, cognitively
speaking, that hindered a child’s academic and
intellectual development.
They were not wrong about the
interference: there is ample evidence that in a
bilingual’s brain both language systems are active
even when he is using only one language, thus
creating situations in which one system obstructs
the other. But this interference, researchers are
finding out, isn’t so much a handicap as a
blessing in disguise. It forces the brain to resolve
internal conflict, giving the mind a workout that
strengthens its cognitive muscles.
Bilinguals, for instance, seem to be more
adept than monolinguals at solving certain kinds of
mental puzzles. In a 2004 study by the
psychologists Ellen Bialystok and Michelle MartinRhee, bilingual and monolingual preschoolers were
asked to sort blue circles and red squares
presented on a computer screen into two digital
bins — one marked with a blue square and the
other marked with a red circle.
In the first task, the children had to sort
the shapes by color, placing blue circles in the bin
marked with the blue square and red squares in
the bin marked with the red circle. Both groups did
this with comparable ease. Next, the children were
asked to sort by shape, which was more
challenging because it required placing the images
in a bin marked with a conflicting color. The
bilinguals were quicker at performing this task.
The collective evidence from a number of
such studies suggests that the bilingual experience
improves the brain’s so-called executive function
— a command system that directs the attention
processes that we use for planning, solving
problems and performing various other mentally
demanding tasks. These processes include ignoring
distractions to stay focused, switching attention
willfully from one thing to another and holding information in mind — like remembering a
sequence of directions while driving.
Why does the tussle between two
simultaneously active language systems improve
these aspects of cognition? Until recently,
researchers thought the bilingual advantage
stemmed primarily from an ability for inhibition
that was honed by the exercise of suppressing one
language system: this suppression, it was thought,
would help train the bilingual mind to ignore
distractions in other contexts. But that explanation
increasingly appears to be inadequate, since
studies have shown that bilinguals perform better
than monolinguals even at tasks that do not
require inhibition, like threading a line through an
ascending series of numbers scattered randomly
on a page.
The key difference between bilinguals and
monolinguals may be more basic: a heightened
ability to monitor the environment. “Bilinguals
have to switch languages quite often — you may
talk to your father in one language and to your
mother in another language,” says Albert Costa, a
researcher at the University of PompeuFabra in
Spain. “It requires keeping track of changes
around you in the same way that we monitor our
surroundings when driving.” In a study comparing
German-Italian bilinguals with Italian monolinguals
on monitoring tasks, Mr. Costa and his colleagues
found that the bilingual subjects not only
performed better, but they also did so with less
activity in parts of the brain involved in
monitoring, indicating that they were more
efficient at it.
The bilingual experience appears to
influence the brain from infancy to old age (and
there is reason to believe that it may also apply to
those who learn a second language later in life).
In a 2009 study led by Agnes Kovacs of
the International School for Advanced Studies in
Trieste, Italy, 7-month-old babies exposed to two
languages from birth were compared with peers
raised with one language. In an initial set of trials,
the infants were presented with an audio cue and
then shown a puppet on one side of a screen. Both
infant groups learned to look at that side of the
screen in anticipation of the puppet. But in a later
set of trials, when the puppet began appearing on
the opposite side of the screen, the babies exposed
to a bilingual environment quickly learned to
switch their anticipatory gaze in the new direction
while the other babies did not.
Bilingualism’s effects also extend into the
twilight years. In a recent study of 44 elderly
Spanish-English bilinguals, scientists led by the
neuropsychologist Tamar Gollan of the University
of California, San Diego, found that individuals
with a higher degree of bilingualism — measured
through a comparative evaluation of proficiency in
each language — were more resistant than others
to the onset of dementia and other symptoms of Alzheimer’s disease: the higher the degree of
bilingualism, the later the age of onset.
Nobody ever doubted the power of
language. But who would have imagined that the
words we hear and the sentences we speak might
be leaving such a deep imprint?
Source: www.nytimes.com
