by Lindsey
Spindle, Georgetown University Medical Center, January 7, 2004
Georgetown University Medical Center researchers today published the first
ever fMRI study of hyperlexia, a rare condition in which children with
some degree of autism display extremely precocious reading skills.
Appearing in Neuron, the case study uncovers the neural mechanisms that
underlie hyperlexia, and suggest that hyperlexia is the true opposite of
the reading disability dyslexia.
Hyperlexia is found in very rare cases in children who are on the "autism
spectrum," meaning they display some characteristics of autism. Like
autistic children, children with hyperlexia have extreme difficulty with
oral communication, social interaction and expression, and yet can read
surprisingly well at a very young age. By some accounts, hyperlexic
children can read at 18 months, sometimes two years before they have ever
uttered a single word. They are drawn to print, sometimes reading all the
signs and license plates they might encounter during a brief walk through
the parking lot.
The child in this case study, Ethan , reads six to eight years in advance
of his age. He read dictionaries in his twos, but spoke his first word at
age three and a half.
"This advanced reading ability, which would likely surprise any parent, is
even more extraordinary given that many of these children begin reading
before mastering spoken language, and sometimes before speaking at all,"
said senior author Guinevere Eden, DPhil, associate professor of
pediatrics and director of Georgetown's Center for the Study of Learning.
"Current theories of reading development posit that decoding skills are
based on linguistic abilities, but our finding suggests that children like
Ethan are able to map sound onto print without a solid language basis."
Eden and her colleagues use fMRI technology to study how brains develop
and function as children learn to read. Most children acquire reading
skills through explicit instruction received over several years of
schooling. In this study, the research team wanted to illucidate the
neural signature for precocious reading, which arose in the absence of any
teaching. Deviations from the normal pattern would suggest that other
regions of the brain might have the potential to become involved in the
reading process and would shed light onto possible compensatory strategies
of the abnormally reading brain.
The hyperlexic boy, Ethan performed several reading tests while lying down
in the fMRI. The researchers then compared hot spots of brain activity in
Ethan as he performed these tasks against brain scans of typically
developing readers, who were matched to Ethan on either chronological or
reading age. Compared to these groups, Ethan demonstrated greater activity
in an area on the left side of the brain that is associated with
understanding the sounds of speech as well as a region on the right side
of the brain that is part of the visual system.
Co-author Peter Turkeltaub, a PhD student, draws an analogy of to the
volume control on a radio. "A region of the brain implicated in reading
skills, the left superior temporal cortex, is like a dial. When the dial
is turned up, you find accelerated readers, or hyperlexics. When the dial
is turned down, as has been shown for dyslexic children, you find
inefficient readers. The more neurological research we do, the better we
may understand how the dial works and what educational interventions may
turn the dial toward its optimum point."
Ethan's parents knew something was peculiar with their son at a young age.
He did not speak, make eye contact, or respond to typical verbal or
non-verbal communications cues. However, he could sit silently in a corner
and read books for hours.
Now at age eleven, Ethan attends a public school with an aide, and was
recently voted class president. He has an insatiable curiosity for books,
magazines, and television, but still has difficulty in social situations.
According to his mom Ilene, "the other kids think he is very smart but
very unusual. There are times when he says things that make the other kids
realize he is not quite the same."
Ilene said, "If I could tell people one thing about hyperlexia, I would
remind them that these children have a tremendous gift and that reading is
the way to unlock their minds and hearts. Don't try to take their books
away to force them to interact with people. Encourage their reading
ability, because they have so much to offer the world, just in a more
unconventional way."
"Neuroscience is allowing us to better characterize people who were before
all bundled under the general autism umbrella," said Eden. "Just as it is
extremely helpful to distinguish a child with Asperberger's,
identification of hyperlexia can be equally as important for early
intervention and appropriately tailored education."
This study was funded by the National Institutes of Health's National
Institute of Child Health and Human Development (NICHD) and National
Association for Autism Research (NAAR).
Georgetown University Medical Center is an internationally recognized
academic medical center with a three-part mission of research, teaching
and patient care (through our partnership with MedStar Health). Our
mission is carried out with a strong emphasis on public service and a
dedication to the Catholic, Jesuit principle of cura personalis--or "care
of the whole person." The Medical Center includes the School of Medicine
and the School of Nursing and Health Studies, both nationally ranked, and
the world renowned Lombardi Cancer Center. For more, please visit
www.georgetown.edu/gumc.
The Georgetown Center for the Study of Learning, which is funded by the
National Institutes of Health, seeks to better understand the neural
mechanisms that enable the acquisition of reading skills, and to identify
new approaches to assess and treat reading disabilities.
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