ANGELES, August 4 — Human brains are stunningly
diverse. No two are identical, not even those of identical
twins. So when scientists are looking at a brain, how
do they know when they’re looking at one that’s
IT’S HARD NOT to recall the scene in the 1974
Mel Brooks comedy “Young Frankenstein” when
Igor selects the “Abby Normal” brain for
his boss to put in the monster.
Researchers are now trying to better understand what
constitutes a “normal” brain by studying
a newly compiled atlas that contains digitally mapped
images of 7,000 of the organs. A decade in the making,
the brain mapping project quietly debuted this summer.
Use of the atlas allows researchers to compare and contrast
these brain images, captured from all sorts of people
living in seven nations on four continents. Most are
between the ages of 20 and 40, but some are as young
as 7 and as old as 90.
Along with the brain images of “normal”
people are those of people suffering from Alzheimer’s,
fetal alcohol syndrome, autism and schizophrenia. More
data are continually being added.
‘A PROJECT BORN OF FRUSTRATION’
“This is a project born of frustration, basically.
For many years, all of us who study brain structure
and function have struggled with the fact that no two
brains are the same — not in shape or size and
certainly not in function,” said Dr. John Mazziotta
of the International Consortium for Brain Mapping, based
at the University of California, Los Angeles. “But
how different they were and how to compare them was
His colleague, Dr. Arthur Toga, says the plan is to
quantify the differences between brains. Understanding
the variations should provide “a good index between
normal populations and a diseased population.”
This brain atlas — freely available to registered
users over the Internet — maps the brains in multiple
dimensions. It charts brain activity, pinpointing the
seat of functions such as speech, memory, emotion and
language and highlighting how those locations can vary
among individuals and populations.
A researcher using this resource can call up any number
of combinations of brains — say, those of a group
of left-handed, 20-year-old Asian women — and
compare them with another population to illustrate their
similarities and differences.
“Might they be different from 90-year-old, left-handed
men?” Toga asked.
Findings from other types of comparisons also might
lead in some surprising directions, Toga suggests, such
as tweaking primary school curricula.
Some data suggest the brain is more receptive to learning
some skills at certain stages of development, so it
should be useful to map the growth of regions of the
brain connected to specific skills.
And since all of the brain images have been stretched,
shrunken or otherwise manipulated to fit a standard
reference, researchers can make apples-to-apples comparisons.
That sort of big-picture view gives clarity that individual
snapshots cannot, said Michael J. Ackerman, of the National
Library of Medicine.
“When you’re able to put it together and
work with it, you begin to see things that weren’t
there when it was in individual pieces. That’s
the beauty of an amalgamated project,” said Ackerman,
who spearheaded the Visible Human Project, a digital
atlas of detailed, three-dimensional representations
of the human body.
Even so, drawing conclusions about the brain is very
Individual differences may foil even the broadest efforts
to generalize, said Stephen Hanson, of Rutgers University,
who is not connected with the brain-mapping project.
“It’s very hard to say, ’that part
of tissue is doing that, and that is not doing that.’
Different tissues might be recruited at different times
— like Tinkertoys,” said Hanson, co-director
of the Rutgers Mind/Brain Analysis Center.
Toga, however, says the comparisons can tell a researcher
where a certain structure or activity is most likely
to occur — even if the precise location varies
from person to person.
“I have to use statistics to be sensitive to what
clearly are very subtle differences,” Toga said.
Original source: MSNBC