Friday, July 13, 2007

WSJ: What Is Normal?

WSJ: Study of Kids' Brains Hopes to Answer: What Is Normal?

Every parent knows that children have minds of their own, shaped by
growing brains that scientists can barely fathom. Researchers strain to tell
symptoms of neural disorder from the natural variations of young brains,
almost infinite in their possibilities.
This summer, brain experts funded by the National Institutes of Health
are finishing the largest systematic clinical study ever of the neurobiology
of youth. In a $30 million project, researchers in six cities have been
combining brain scans, psychological profiles, medical exams and
intelligence tests gathered from hundreds of healthy children to answer a
fundamental question about brain development that nags parents and pediatric
practitioners alike: What is normal? When completed, this NIH brain archive
promises to become the first clinical benchmark by which normal development
can be judged, matching behavior to brain anatomy from birth through
adolescence. With it, specialists should be able to understand better
problems such as autism, in which neural miscues undermine the mind.
Educators bedeviled by child-rearing fads and untested teaching theories
should be able to match alterations in brain structure to the rise and fall
of learning skills. "Once we know the map, we can tell what nudges the brain
for good or ill," said NIH brain imaging expert Jay Giedd.
By any standard, every child's brain is an experiment.
From a single cell in the womb, it swells at such speed -- 250,000
cells a minute -- that by early childhood it has more neurons and nerves
connecting them than do any older, wiser adults. It is buffeted by
tumultuous bursts of growth that prime it for mastering new skills and ways
of thinking. Yet, so little is certain about how it changes throughout
childhood that scientists don't know what ought to be expected, said Cornell
University expert B.J. Casey, who helped pioneer brain imaging in children.
Not only is every new brain different from any other, but the
variations within each one as it adapts, swells and contracts confound
analysis. "A developing brain looks weird," said pediatric neurologist
Katrina Gwinn at the National Institute of Neurological Disorders and
Stroke, who directs the NIH project. "Something that might be normal in an
adult might look abnormal in a child."
Until recently, little was known about how normal human brains change
as they grow because conventional medical imaging techniques were too
dangerous or invasive to be used with any but the sickest children. The NIH
survey takes advantage of newer techniques benign enough that infants can
safely nap inside while their brain cells are bombarded with magnetic
Seeking as broad a measure of childhood as possible, research teams in
Boston, Philadelphia, Cincinnati, St. Louis, Los Angeles and Houston
selected 385 girls and boys from among 35,000 families to ensure that the
data would reflect the country's racial, ethnic and economic diversity. "So
many studies are done only with white kids from suburban areas," said Dr.
Gwinn. "We worked hard to get different demographics."
Researchers even sought the proper mix of right- and left-handers. The
children, between six and 18 years old, were screened to ensure they were
free of illness, genetic predispositions, prenatal risk factors, toxic
environmental exposures or chronic health problems that might affect their
brains. "These are really healthy brains," said project researcher Deborah
Waber at Children's Hospital Boston. Newborns have since been included in
the study.
The children were scanned periodically using three techniques:
structural magnetic resonance imaging to catch changes in the brain's gray
matter, which contains neurons; diffusion tensor imaging to monitor its
white matter of connecting nerve fibers; and magnetic resonance spectroscopy
to track the ups and downs of brain chemistry. To match changes in brain
anatomy to mental abilities, the youngsters also regularly took tests of IQ,
dexterity, spatial ability, memory and cognitive skills. "So we are actually
able to follow individual children and look at snapshots of the same brain
over time," said Dr. Waber.
In its essence, this biomedical mosaic is a national portrait of the
child mind.
It reveals that gender differences and income disparities matter less
than previously believed and that health matters more, project researchers
reported recently in the Journal of the International Neuropsychological
Healthy girls and boys do equally well on most cognitive tasks. Boys
perform better at analyzing and manipulating shapes and patterns, while
girls perform better on processing speed and motor dexterity. No differences
were measured in calculation ability, suggesting boys and girls have an
equal aptitude for math. By age 12, many children are as proficient as
adults by most measures of mental performance.
These unusually fit, diverse children outperformed all those in
previous research on tests that measured IQ, memory, reading and math
ability, and development of social skills.
It may be years before the findings have been fully analyzed and
applied. Until then, the NIH brain project, like the children it documents,
is a promise of things to come.
Now don't get too excited. You know what's going to happen don't you? They'll complete this giant expensive study, interpret it themselves, and not share the data. That way they can paternally share their sweeping generalizations that benefit the government's interests and back past decisions. They can spin on the data they need to keep us parents under control at their leisure. Just like they've done with the vaccine data. You just watch.

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