|
Inside the Autistic Mind
A wealth of new brain research--and poignant
testimony from people who have autism--is lifting the veil on this
mysterious condition
By CLAUDIA WALLIS
May 15, 2006
The road to Hannah's mind opened a few days
before her 13th birthday.
Her parents, therapists, nutritionists and
teachers had spent years preparing the way. They had moved mountains
to improve her sense of balance, her sensory perception and her
overall health. They sent in truckloads of occupational and physical
therapy and emotional support. But it wasn't until the fall of 2005
that traffic finally began to flow in the other direction. Hannah,
whose speech was limited to snatches of songs, echoed dialogue and
unintelligible utterances, is profoundly autistic, and doctors
thought she was most likely retarded. But on that October day, after
she was introduced to the use of a specialized computer keyboard,
Hannah proved them wrong. "Is there anything you'd like to say,
Hannah?" asked Marilyn Chadwick, director of training at the
Facilitated Communication Institute at Syracuse University.
With Chadwick helping to stabilize her right
wrist and her mother watching, a girl thought to be incapable of
learning to read or write slowly typed, "I love Mom."
A year and a half later, Hannah sits with her
tutor at a small computer desk in her suburban home outside New York
City. Facilitated communication is controversial (critics complain
that it's often the facilitator who is really communicating), but it
has clearly turned Hannah's life around. Since her breakthrough, she
no longer spends much of her day watching Sesame Street and Blue's
Clues. Instead, she is working her way through high school biology,
algebra and ancient history. "It became obvious fairly quickly that
she already knew a lot besides how to read," says her tutor, Tonette
Jacob.
During the silent years, it seems, Hannah was
soaking up vast storehouses of information. The girl without
language had an extensive vocabulary, a sense of humor and some
unusual gifts. One day, when Jacob presented her with a page of 30
or so math problems, Hannah took one look, then typed all 30
answers. Stunned, Jacob asked, "Do you have a photographic memory?"
Hannah typed "Yes."
Like many people with autism, Hannah is so
acutely sensitive to sound that she'll catch every word of a
conversation occurring elsewhere in the house, which may account for
much of her knowledge. She is also hypersensitive to visual input.
Gazing directly at things is difficult, so she often relies on her
almost preternatural peripheral vision. Hannah's newfound ability to
communicate has enabled her intellect to flower, but it also has a
dark side: she has become painfully aware of her own autism. Of
this, she writes, "Reality hurts."
MORE THAN 60 YEARS AFTER AUTISM WAS first
described by American psychiatrist Leo Kanner, there are still more
questions than answers about this complex disorder. Its causes are
still uncertain, as are the reasons for the rapidly rising incidence
of autism in the U.S., Japan, England, Denmark and France. But
slowly, steadily, many myths about autism are falling away, as
scientists get a better picture of what's going on in the bodies and
brains of people with autism and as more of those who are profoundly
affected, like Hannah, are able to give voice to their experience.
Among the surprises:
• Autism is almost certainly, like cancer, many
diseases with many distinct causes. It's well known that there's a
wide range in the severity of symptoms--from profound disability to
milder forms like Asperger syndrome, in which intellectual ability
is generally high but social awareness is low. Indeed, doctors now
prefer the term Autistic Spectrum Disorders (ASD). But scientists
suspect there are also distinct subtypes, including an early-onset
type and a regressive type that can strike as late as age 2.
• Once thought to be mainly a disease of the
cerebellum--a region in the back of the brain that integrates
sensory and motor activity, autism is increasingly seen as a
pervasive problem with the way the brain is wired. The distribution
of white matter, the nerve fibers that link diverse parts of the
brain, is abnormal, but it's not clear how much is the cause and how
much the result of autism.
• The immune system may play a critical role in
the development of at least some types of autism. This suggests some
new avenues of prevention and treatment.
• Many classic symptoms of autism--spinning,
head banging, endlessly repeating phrases--appear to be coping
mechanisms rather than hard-wired behaviors. Other classic
symptoms--a lack of emotion, an inability to love--can now be
largely dismissed as artifacts of impaired communication. The same
may be true of the supposedly high incidence of mental retardation.
• The world of autism therapy continues to be
bombarded by cure-of-the-day fads. But therapists are beginning to
sort out the best ways to intervene. And while autism is generally a
lifelong struggle, there are some reported cases in which kids who
were identified as autistic and treated at an early age no longer
exhibit symptoms.
THE CURIOUS INCIDENCE
DR. THOMAS INSEL, DIRECTOR OF THE National
Institute of Mental Health (NIMH), which funds much of the nation's
autism research, remembers a time when the disorder was rarely
diagnosed. "When my brother trained at Children's Hospital at
Harvard in the 1970s, they admitted a child with autism, and the
head of the hospital brought all of the residents through to see,"
says Insel. "He said, 'You've got to see this case; you'll never see
it again.'"
Alas, he was mistaken. According to the Centers
for Disease Control and Prevention (CDC), about 1 in 166 American
children born today will fall somewhere on the autistic spectrum.
That's double the rate of 10 years ago and 10 times the estimated
incidence a generation ago. While some have doubted the new figures,
two surveys released last week by the CDC were in keeping with this
shocking incidence.
No one can say why the numbers have soared.
Greater awareness and public health campaigns to encourage earlier
diagnosis have surely played a part, since in the past, many such
children were probably labeled retarded or insane and hidden in
institutions. But environmental factors may also be contributing to
the spike. To get to the bottom of that mystery and others, federal
funding for autism research has more than tripled in the past
decade, to $100 million, although it pales in comparison with the
estimated $500 million spent on childhood cancers, which affect
fewer youngsters.
At the Center for Children's Environmental
Health and Disease Prevention at the University of California at
Davis, toxicologist Isaac Pessah is studying hair, blood, urine and
tissue samples from 700 families with autism. He's testing for 17
metals, traces of pesticides, opioids and other toxicants. In March
Pessah caused a stir by releasing a study that showed that even the
low level of mercury used in vaccines preserved with thimerosal,
long a suspect in autism, can trigger irregularities in the
immune-system cells--at least in the test tube. But he does not
regard thimerosal (which has been removed from routine childhood
vaccines) as anything like a smoking gun. "There's probably no one
trigger that's causing autism from the environmental side," says
Pessah, "and there's no one gene that's causing it."
Indeed, most researchers believe autism arises
from a combination of genetic vulnerabilities and environmental
triggers. An identical twin of a child with autism has a 60% to 90%
chance of also being affected. And there's little doubt that a
vulnerability to ASD runs in some families: the sibling of a child
with autism has about a 10% chance of having ASD. Gene scientists
working on autism have found suspicious spots on chromosomes 2, 5,
7, 11 and 17, but there are probably dozens of genes at work. "We
think there are a number of different autisms, each of which could
have a different cause and different genes involved," says David
Amaral, research director of the MIND (Medical Investigation of
Neurodevelopmental Disorders) Institute, also at U.C. Davis.
Amaral is heading MIND's efforts to assemble a
database of clinical, behavioral and genetic information on 1,800
autistic kids. One goal is to clearly define autism subtypes. "It's
hard to do the genetics if you're talking about four or five
different syndromes," says NIMH chief Insel. "Does the presence of
seizures define a separate illness? What about the kids who seem to
develop normally for the first year and a half and then regress--is
that a separate thing?" And what about the large number of autistic
kids who have serious gastrointestinal problems and the many with
immune dysfunctions--are they distinct subtypes?
Amaral and colleague Judy Van de Water believe
they are onto a major discovery about the origins of at least one
type of autism--a strongly familial variety. They have detected
aberrant antibodies in the blood of kids from families with a
pattern of ASD and, significantly, in mothers with more than one
autistic child. "These antibodies are actually raised against
proteins in the fetal brain," says Amaral, who recently submitted a
paper on the discovery. The working hypothesis is that these
antibodies may alter brain development in ways that lead to autism.
If correct, the finding could lead to a maternal blood test and the
use of a therapy called plasmapheresis to clear antibodies from the
mother's blood. "You get a sense of the excitement," says Amaral,
"if you could prevent, say, 20% of kids from getting autism. But we
don't want to raise false hopes."
THE AUTISTIC BRAIN
WHETHER THE CAUSE IS MATERNAL antibodies, heavy
metals or something else, there is no question that the brains of
young children with autism have unusual features. To begin with,
they tend to be too big. In studies based on magnetic resonance
imaging (MRI) and basic tape-measure readings, neuroscientist Eric
Courchesne at Children's Hospital of San Diego showed that while
children with autism are born with ordinary-size brains, they
experience a rapid expansion by age 2--particularly in the frontal
lobes. By age 4, says Courchesne, autistic children tend to have
brains the size of a normal 13-year-old. This aberrant growth is
even more pronounced in girls, he says, although for reasons that
remain mysterious, only 1 out of 5 children with autism is female.
More recent studies by Amaral and others have found that the
amygdala, an area associated with social behavior, is also oversize,
a finding Amaral believes is related to the high levels of anxiety
seen in as many as 80% of people with autism.
Harvard pediatric neurologist Dr. Martha
Herbert reported last year that the excess white matter in autistic
brains has a specific distribution: local areas tend to be
overconnected, while links between more distant regions of the brain
are weak. The brain's right and left hemispheres are also poorly
connected. It's as if there are too many competing local services
but no long distance.
This observation jibes neatly with imaging
studies that look at live brain activity in autistic people. Studies
using functional MRI show a lack of coordination among brain
regions, says Marcel Just, director of Carnegie Mellon's Center for
Cognitive Brain Imaging in Pittsburgh, Pa. Just has scanned dozens
of 15- to 35-year-old autistic people with IQs in the normal range,
giving them thinking tasks as he monitors their brain activity. "One
thing you see," says Just, "is that [activity in] different areas is
not going up and down at the same time. There's a lack of
synchronization, sort of like a difference between a jam session and
a string quartet. In autism, each area does its own thing."
What remains unclear is whether the
interconnectivity problem is the result of autism or its cause.
Perhaps all that excess wiring is like the extra blood vessels
around the heart of a person who has suffered a heart attack--the
body's attempt to route around a problem. Or perhaps the abnormal
growth of the brain has to do with the immune system; researchers at
Johns Hopkins have found signs that autistic brains have chronic
inflammation. "It's impossible to tell the chicken from the egg at
this point," Just says.
Autistic people have been shown to use their
brains in unusual ways: they memorize alphabet characters in a part
of the brain that ordinarily processes shapes. They tend to use the
visual centers in the back of the brain for tasks usually handled by
the prefrontal cortex. They often look at the mouth instead of the
eyes of someone who is speaking. Their focus, says psychologist Ami
Klin of Yale's Child Study Center, is "not on the social
allegiances--for example, the longing gaze of a mother--but physical
allegiances--a mouth that moves."
Do these differences reflect fundamental
pathology, or are they downstream effects of some more basic
problem? No one knows. But the fact that early intervention brings
better results for children with ASD could be a clue that some of
the odd brain anatomy and activity are secondary--and perhaps even
preventable. Studies that look at whether early therapy might help
normalize the brain are beginning at York University in Toronto, but
results are probably years away.
AUTISM FROM THE INSIDE
IN THE MEANTIME, 300,000 SCHOOL-AGE American
children and many adults are attempting to get through daily life
with autism. The world has tended to hear from those who are highest
functioning, like Temple Grandin, the author and Colorado State
University professor of livestock behavior known for designing
humane slaughterhouses. But the voices of those more severely
affected are beginning to be heard as well. Such was the case with
Sue Rubin, 27, a college student from Whittier, Calif., who has no
functional speech and matches most people's stereotyped image of a
retarded person; yet she was able to write the narration for the
Oscar-nominated documentary about her life, Autism Is a World.
What such individuals have to say about their
experience is offering new clues to their condition. It also
conforms remarkably to what scientists see inside their brains. By
and large, people with ASD have difficulty bringing different
cognitive functions together in an integrated way. There is a
tendency to hyperfocus on detail and miss the big picture.
Coordinating volition with movement and sensation can be difficult
for some. Chandima Rajapatirana, an autistic writer from Potomac,
Md., offers this account: "Helplessly I sit while Mom calls me to
come. I know what I must do, but often I can't get up until she
says, 'Stand up,'" he writes. "[The] knack of knowing where my body
is does not come easy for me. Interestingly I do not know if I am
sitting or standing. I am not aware of my body unless it is touching
something ... Your hand on mine lets me know where my hand is.
Jarring my legs by walking tells me I am alive."
Such descriptions shed light on seemingly
self-destructive behavior like biting, scratching, spinning and head
banging. For people like Rajapatirana, banging against a wall can be
a useful way to tell, quite literally, where their head is at.
"Before we extinguish [such behaviors], we need to understand what
they are telling us," writes Judith Bluestone, a Seattle-based
therapist who is autistic, in The Fabric of Autism.
In his new book Send in the Idiots, British
journalist Kamran Nazeer, who is also autistic, describes the need
for repetitive motions or words as a search for "local coherence" in
a world full of jarring randomness. He also conveys the social
difficulties: "Striking up conversations with strangers," he writes,
"is an autistic person's version of extreme sports." Indeed, at a
recent retreat for people with ASD, attendees wore colored tags
indicating their comfort level with spontaneous conversation: red
meant don't approach, yellow meant talk if we've already met, green
indicated, "I'd love to talk, but I'm not good at initiating."
Perhaps the worst fate for a person with ASD is
to have a lively intelligence trapped in a body that makes it
difficult for others to see that the lights are on. Neuroscientist
Michael Merzenich at the University of California, San Francisco,
studied an autistic boy who is unable to speak or even sustain his
attention to a task for more than a few moments, and yet is aware of
his condition and writes remarkable poetry. How many other autistic
kids, Merzenich wonders, "are living in a well where no one can hear
them"?
Luckily for Hannah, her voice and thoughts are
being heard. Since learning to type, she has begun to speak a few
words reliably--"yes," "no" and the key word "I"--to express her
desires. All this seems miraculous to her parents. "I was told to
give up and get on with my life," says her mother. Now she and her
husband are thinking about saving for college.
—With reporting by With reporting by Dan
Cray/Los Angeles
http://www.time.com/time/magazine/0,9263,7601060515,00.html#Anchortoc
|
