Bilingualism gives children a distinct cognitive advantage over
their monolingual peers, says a study by a York University professor.

The
study, published in the journal Developmental Psychology, finds that
bilingual children outperform monolingual students on tasks involving
executive control – the cognitive processes that allow for abstract
thinking, planning, initiating and inhibiting actions. Three separate
experiments on six-year-old students demonstrated that children who
routinely speak more than one language can better focus on pertinent
information and suppress their attention to distracting or irrelevant
items.

“This ability to selectively focus on wanted
information and ignore distracting elements is a central feature of all
higher thought,” says study author Ellen Bialystok, Distinguished
Research Professor of Psychology in York’s Faculty of Health. “These
results have implications for our overall understanding of how
bilingualism influences cognitive development in its early stages,” she
says.

Researchers evaluated bilingual and
monolingual children attending the same public school in a middle-class
neighbourhood of Toronto. Bilingual students spoke a language other
than English at home, including Cantonese, French, Russian, Mandarin,
Urdu, Hindi and Spanish. Six-year-olds were selected as they are at a
critical stage in their cognitive development: previous studies have
established this as the age at which measurable differences in the
brains of bilingual children appear.

Participants
were tested using standardized neuropsychological tests including the
global-local task and the trail-making task (TMT). The latter is widely
used to assess brain functioning in both children and adults, and to
diagnose learning disabilities.

The TMT requires
subjects to create a sequence, either by connecting scattered numbers
in a continuous order, or alternating numbers with corresponding
letters of the alphabet. During this test, children need to hold in
mind the current place in the sequence while searching for the next
element through a distracting space filled with other digits.

”The
surprising finding on the TMT was that bilingual children not only
performed better than monolingual children on the difficult condition
that involved alternating between letters and numbers but also on the
simple condition in which they just connected consecutive numbers,”
says Bialystok.

The global-local task investigates
the ability to perceptually zoom in and out, successfully delineating a
system from its parts. Usually, global information is processed faster
and interferes with the identification of local elements.

To
complete both these tasks, participants must employ critical executive
functions, including inhibition (ignoring misleading cues), updating
(monitoring a display in the context of current instructions) and
switching (adjusting one’s response according to instructions).

Results
show that bilingual children develop executive control over a broad
range of processes, not only via inhibition and conflict resolution, as
suggested by previous research.

Monolingual and
bilingual children also performed similarly on tests of vocabulary,
digit span, verbal fluency and box completion; where there were
differences, it was the monolinguals who achieved slightly higher
scores. Bilinguals obtained slightly lower scores on vocabulary and
forward digit span but performed significantly better in all aspects of
the TMT and global-local tasks. They completed the tasks more rapidly
and more accurately than the monolinguals.

”This
doesn’t mean that bilinguals are simply faster responders,” says
Bialystok. “Both groups completed the control conditions for these
tests at the same speed, which rules out basic response speed as the
sole explanation for group differences.”

Bialystok
also emphasizes the diagnostic implications of her research. Since the
TMT is used to establish the presence of learning disabilities such as
Attention Deficit Hyperactivity Disorder (ADHD), it may not be valid
for bilingual students.

“Diagnostic tools may need
to be adjusted somewhat if bilingualism – which is so common – can
modify children’s performance, and perhaps confuse results,” she says.

The
study, “Global-Local and Trail-Making Tasks by Monolingual and
Bilingual Children: Beyond Inhibition,” was published in January 2010.

 

Source: Exchange Morning Post – http://tinyurl.com/ylq4whc