Autism involves whole brain
Too much information can be
September 19, 2006
When Ethan Meeder doesn't follow
directions at school, it's not because he's stubborn.
The 13-year-old seventh-grader
from the Pittsburgh area has a brain that shuts down when he has
to process too much at one time.
For example, last spring Meeder's
teacher gave him four commands, one right after the other. "He
just melted down," says his mom, Cindy Meeder.
Ethan has an average IQ, yet he
has trouble with things that most of us take for granted, such
as following directions. "He tests like he should be able to do
these things, but he can't," Cindy Meeder says.
Ethan has autism, an incurable
brain disorder that affects about 300,000 school-age children in
the United States, according to Los Angeles-based Cure Autism
Scientific studies out in July and
August have helped increase scientists' understanding of how
autism affects the brain. The studies fit with other research
that suggests that autism is not limited to a few brain regions
as once thought, but instead is a global disorder that affects
reasoning, memory, balance, multi-tasking and other skills.
In the past, scientists believed
autism was confined to the brain areas that controlled social
interaction, language and behavior. But the new findings
indicate that autism affects many parts of the brain and
possibly the wiring that connects one brain region to another.
While some kids with autism are
mentally retarded, University of Pittsburgh researcher Nancy
Minshew and colleagues studied 56 children with autism who had
an IQ of at least 80, close to the average IQ of 100.
The Pittsburgh team gave the kids
a battery of tests that assessed memory, attention and other
skills. The team found that those with autism had no trouble
with basic tasks involving spelling and grammar.
But the study did find that kids
with autism faltered when asked to do more complex tasks. So
while they're good at details, they have trouble piecing words
together to get the meaning of an entire paragraph or story.
They also had difficulty
understanding figures of speech such as idioms and metaphors. If
you tell a child with autism to "hop to it," they might
literally start to hop around the room, Minshew says.
The study, which appears in the
August issue of Child Neuropsychology, suggests that kids with
autism have trouble processing lots of complex information. When
a teacher or parent gives a series of rapid-fire commands, the
kid with autism might get confused and then freeze, Minshew
A second study suggests a
biological explanation for the difficulty: A study published
online in the journal Cerebral Cortex indicates that the corpus
callosum, which connects one part of the brain to another, may
be abnormal in autism. In this study, people with autism were
asked to complete a computer task that requires two parts of the
brain to work together.
Brain scans showed that people
with autism relied mostly on one brain area to solve the
computer puzzle, says Marcel Just, the lead author of the study
and director of the Center for Cognitive Brain Imaging at
Carnegie Mellon University. The findings suggest that people
with autism don't have an efficient way to transfer information
from one brain region to another, he says.