STUDY PROVIDES EVIDENCE THAT AUTISM AFFECTS FUNCTIONING OF ENTIRE BRAIN

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U.S. Department of Health and Human Services 
NATIONAL INSTITUTES OF HEALTH 
NIH News 
National Institute of Child Health and Human Development (NICHD)
http://www.nichd.nih.gov/
National Institute on Deafness and Other Communication Disorders (NIDCD)
http://www.nidcd.nih.gov/

EMBARGOED FOR RELEASE: Wednesday, August 16, 2006, 12:01 a.m. ET

CONTACT: Robert Bock or Marianne Glass Miller, 301-496-5133,
bockr@xxxxxxxxxxxx 

STUDY PROVIDES EVIDENCE THAT AUTISM AFFECTS FUNCTIONING OF ENTIRE BRAIN
Previous View Held Autism Limited to Communication, Social Behavior, and
Reasoning

A recent study provides evidence that autism affects the functioning of
virtually the entire brain, and is not limited to the brain areas
involved with social interactions, communication behaviors, and
reasoning abilities, as had been previously thought. The study,
conducted by scientists in a research network supported by the National
Institutes of Health (NIH), found that autism also affects a broad array
of skills and abilities, including those involved with sensory
perception, movement, and memory.

The findings, appearing in the August "Child Neuropsychology", strongly
suggest that autism is a disorder in which the various parts of the
brain have difficulty working together to accomplish complex tasks.

The study was conducted by researchers in the Collaborative Program of
Excellence in Autism (CPEA), a research network funded by two components
of the NIH, the National Institute of Child Health and Human Development
and the National Institute on Deafness and Other Communication
Disorders.

"These findings suggest that further understanding of autism will likely
come not from the study of factors affecting one brain area or system,
but from studying factors affecting many systems," said the director of
NICHD, Duane Alexander, M.D.

People with autism tend to display 3 characteristic behaviors, which are
the basis of the diagnosis of autism, explained the study's senior
author, Nancy Minshew, M.D., Professor of Psychiatry and Neurology at
the University of Pittsburgh School of Medicine. These behaviors involve
difficulty interacting socially, problems with verbal and non-verbal
communications, and repetitive behaviors or narrow, obsessive interests.
Traditionally, Dr. Minshew said, researchers studying autism have
concentrated on these behavioral areas.

Within the last 20 years, however, researchers began studying other
aspects of thinking and brain functioning in autism, discovering that
people with autism have difficulty in many other areas, including
balance, movement, memory, and visual perception skills.

In the current study, Dr. Minshew and her colleagues administered a
comprehensive array of neuropsychological tests to a group of children
with autism. The researchers tested 56 autistic children, and compared
their responses to those of 56 children who did not have autism. The
children with autism were classified as having higher functioning autism
-- an I.Q. of 80 or above, and the ability to speak, read, and write.
All of the children in the study ranged in age from 8 to 15 years. The
purpose of the test array, Dr. Minshew said, was to determine whether
there were any patterns in mental functioning unique to autism.

"We set out to find commonalities across a broad range of measures, so
that we could make inferences about what's going on in the brain," Dr.
Minshew said.

The researchers found that, across the entire series of tests, the
children with autism performed as well as -- and in some instances even
better than -- the other children on measures of basic functioning.
Uniformly, however, they had trouble with complex tasks.

For example, regarding visual and spatial skills, the children with
autism were very good at finding small objects in a cluttered visual
field, on tasks like finding Waldo in the "Where's Waldo" picture books
series. However, when asked to perform a complex task, like telling the
difference between the faces of similar looking people, they had great
difficulty.

Although their memory for the detail in a story was phenomenal, the
children with autism had great difficulty comprehending the story. Many
were highly proficient at spelling and had a good command of grammar,
but had difficulty understanding complex figures of speech, like idioms
and metaphors.

"We see this with our patients," Dr. Minshew said. "If you use an
expression like 'hop to it,' a child with autism may literally hop."

Other complex tasks were also difficult for them. The children with
autism either had poor handwriting, or wrote very slowly. Many had
difficulty tying their shoes and with using scissors.

"These findings show that you can't compartmentalize autism under three
basic areas," Dr. Minshew said. "It's much more complex than that."

Dr. Minshew explained that the major implication of the finding is that
when seeking to understand autism, researchers need to look for a cause
or causes that affect multiple brain areas, rather than limiting their
search to brain areas dealing with the three characteristic behaviors
involving social interactions, communication, and repetitive behaviors
or obsessive interests.

"Our paper strongly suggests that autism is not primarily a disorder of
social interaction, but a global disorder affecting how the brain
processes the information it receives -- especially when the information
becomes complicated."

In previous research with an imaging technology known as functional
magnetic resonance imaging, or fMRI, Dr. Minshew and her coworkers
determined that adults with autism have abnormalities in the
neurological wiring through which brain areas communicate. In those
studies, the researchers found that people with autism had difficulty
performing certain complex tasks that involved brain areas working
together. (This research is described in previous releases,
http://www.nichd.nih.gov/new/releases/final_autism.cfm, and
http://www.nichd.nih.gov/new/releases/autism_brain_structure.cfm.)

Dr. Minshew said that such abnormalities in brain circuitry provide the
most likely explanation for why the children with autism in the current
study have difficulty with complex tasks that require coordination among
brain regions but do well on tasks that require only one region of the
brain at a time.

The researchers undertook the current study as a follow up to an earlier
study they did of adults with autism. The researchers studied children
to determine if the features of autism were consistent throughout life,
or changed as people with autism grow older. For the most part, the
current study revealed that both adults and children with autism
experience the same kinds of difficulties with complex tasks.

One difference is that adults with autism appear to score higher on
tests involving sensory interpretation than do children with autism.
Such tests would involve identifying a number traced on a finger tip, or
identifying an object placed in one's hand without looking at it. Dr.
Minshew said that as people with autism grow older, they may have less
sensory difficulty than they did as children.

Still, adults with autism fare much worse on tests of complex language
and reasoning than do other adults. This gap in complex language and
reasoning ability between the two groups is not as pronounced when
children with autism are compared to other children. This is because
children's brains have not yet developed these skills, Dr. Minshew said.
However, the gap widens with time. As typical children get older, they
develop these higher order language and reasoning skills while
adolescents and adults with autism do not.

The NICHD sponsors research on development, before and after birth;
maternal, child, and family health; reproductive biology and population
issues; and medical rehabilitation. For more information, visit the
Institute's Web site at http://www.nichd.nih.gov/.  

The National Institutes of Health (NIH) -- "The Nation's Medical
Research Agency" -- includes 27 Institutes and Centers and is a
component of the U.S. Department of Health and Human Services. It is the
primary federal agency for conducting and supporting basic, clinical and
translational medical research, and it investigates the causes,
treatments, and cures for both common and rare diseases. For more
information about NIH and its programs, visit www.nih.gov.
  
##
 
This NIH News Release is available online at:
http://www.nih.gov/news/pr/aug2006/nichd-16.htm.

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