Babies
rehearse for speech months before their first words
Washington: Babies' brains rehearse speech mechanics months
before they utter their first words, a new study has found. Infants can tell
the difference between sounds of all languages until about 8 months of age when
their brains start to focus only on the sounds they hear around them.
However, it's been unclear how this transition occurs.
The study by the University of Washington researchers in 7-
and 11-month-old infants shows that speech sounds stimulate areas of the brain
that coordinate and plan motor movements for speech. The research suggests that
baby brains start laying down the groundwork of how to form words long before
they actually begin to speak, and this may affect the developmental transition.
"Most babies babble by 7 months, but don't utter their
first words until after their first birthdays," said lead author Patricia
Kuhl, who is the co-director of the UW's Institute for Learning and Brain
Sciences.
"Finding activation in motor
areas of the brain when infants are simply listening is significant, because it
means the baby brain is engaged in trying to talk back right from the start and
suggests that 7-month-olds' brains are already trying to figure out how to make
the right movements that will produce words," said Kuhl.
Kuhl and her research team believe this practice at motor
planning contributes to the transition when infants become more sensitive to
their native language.
The results emphasise the importance of talking to kids
during social interactions even if they aren't talking back yet. "Infants'
brains are preparing them to act on the world by practicing how to speak before
they actually say a word," said Kuhl. In the experiment, infants sat in a
brain scanner that measures brain activation through a noninvasive technique
called magnetoencephalography.
Nicknamed MEG, the brain scanner resembles an egg-shaped
vintage hair dryer and is completely safe for infants. The 57 babies each
listened to a series of native and foreign language syllables such as
"da" and "ta" as researchers recorded brain responses. They
listened to sounds from English and Spanish. Researchers observed brain
activity in an auditory area of the brain called the superior temporal gyrus,
as well as in Broca's area and the cerebellum, cortical regions responsible for
planning the motor movements required for producing speech.
This pattern of brain activation occurred for sounds in the
7-month-olds' native language (English) as well as in a non-native language
(Spanish), showing that at this early age infants are responding to all speech
sounds, whether or not they have heard the sounds before.
In the older infants, brain activation was different.
The study was published in the
journal PNAS.
Source: www.zeenews.india.com 16.07.2014
Device to
diagnose diabetes at home
Washington: In a significant discovery, researchers have
invented a cheap and hand-held device to diagnose type-1 diabetes at home.
People who are at risk of developing type-1 diabetes can
also benefit from the nanotech microchip-based device because it will allow
doctors to quickly track if they can have the disease later in life.
"With the new test, not only do we anticipate being
able to diagnose diabetes more efficiently and more broadly, we will also
understand diabetes better," said Brian Feldman, an assistant professor at
Stanford University's school of medicine.
The handheld microchips distinguish between the two main
forms of diabetes mellitus - type-1 and type-2 - which are both characterised
by high blood-sugar levels but have different causes and treatments. The
microchip relies on a fluorescence-based method for detecting the antibodies.
The team's innovation is that the glass plates forming the
base of each microchip are coated with an array of nanoparticle-sized islands
of gold, which intensify the fluorescent signal, enabling reliable antibody
detection.
The test was validated with blood
samples from people newly diagnosed with diabetes and from people without
diabetes.
Both groups had the old test and the microchip-based test
performed on their blood.
Type-1 diabetes is an autoimmune disease caused by an
inappropriate immune-system attack on healthy tissue. The disease begins when a
person's own antibodies attack the insulin-producing cells in the pancreas.
The auto-antibodies are present in people with type-1 but
not those with type-2, which is how tests distinguish between them.
"Even if you do not have diabetes yet, if you have one
auto-antibody linked to diabetes in your blood, you are at significant risk;
with multiple auto-antibodies, it is more than 90 percent risk," Feldman
said in a paper published in the journal Nature Medicine.
The new microchip uses no radioactivity, produces results in
minutes and requires minimal training to use.
Each chip, expected to cost about $20 (Rs.1,100) to produce,
can be used for upward of 15 tests.
The microchip also uses a much
smaller volume of blood than the older test, researchers said.
Source: www.zeenews.india.com
16.07.2014
Raise your words, not voice. It is rain that grows flowers,
not thunder
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