IN THEIR EYES: Some autistic individuals have eye-movement deficits, and a new study shows that a similar pattern can be found in some of their close relations--even those who don't have other signs of the disorder.
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The tangled web of autism symptoms and genetic markers has left researchers searching for patterns and trends in unusual places. New work examining the subtle symptoms shared by close relatives has underscored the disease's heritability. Findings published online August 2 in Archives of General Psychiatry add to the growing list of familial clues about the disease: shared eye-movement deficits.
Researchers working at the University of Illinois at Chicago's (U.I.C.) Center for Cognitive Medicine have found a striking trend: those with autistic relatives are more likely to show disrupted eye movement similar to their afflicted relation.
Large-scale genetic studies have turned up nuanced and conflicting results about the genetic basis of autism and its myriad symptoms. Other research has discovered that many people with an autistic relative or child might themselves have some subtle behavior variant as well, such as obsessive-compulsive tendencies or communication problems.
Eye movement is easier to study neurologically than complex social and behavioral patterns—in large part because "we know a lot about what parts of the brain are involved," says Matthew Mosconi, an assistant professor of psychiatry at the U.I.C. and lead author of the new study. And the new findings examine basic deficits unclouded by social tendencies, such as the aversion many people with autism spectrum disorder have to looking at faces.
To monitor test subjects' eye movements, fluidity and response time, the researchers used exacting projection and recording equipment. They tested 57 people (ages eight to 54) with immediate family members who had autism and 40 volunteers who did not have a family history of mental disorder. None of the subjects were themselves autistic or had other developmental disorders.
Subjects were tested for their rapid eye movement that allows focus to shift on multiple objects in the field of vision (aka saccade) and ability to follow objects moving across the visual field, known as smooth-pursuit.
Although not everyone with autism exhibits eye-movement deficits—and not everyone has both of the types studied—those who do, display a very specific and measurable difference that is extremely rare in the general, unaffected population, Mosconi says. "So when you do see some subtle deviation, that's very important," he notes.
The oculomotor deficits are subtle enough to "require very sensitive lab tests" to detect them, Mosconi says. Other differences in behavior and communication that have been found in some first-degree nonafflicted relatives of people with autism are more noticeable and can sometimes be detected in casual conversation.
Family members' eye-movement capabilities were not strongly correlated with their scores on other cognitive or social-behavioral tests, a result that Mosconi calls "exciting." Although weak relationships are often a disappointment in disease research, he says, this trend was illuminating "because that tells us that we're getting at a different part of the puzzle"—to which "there are so many pieces," he notes.
Studying individuals and families who have these eye abnormalities might eventually be able to shed light on the genetics behind the affected parts of the brain, Mosconi notes. "We wanted to move even a step closer—to try to attach these broader characteristics to genes," he says. Evidence that eye-tracking trouble is prevalent in some autistic individuals and their families suggests that abnormalities in the cerebellum—which helps control motor skills, attention and language—might be to blame. And that would mean that researchers could next "look in a much more focused way [for] specific genes that might be involved in cerebellar development."
But with genetic or other profiles for autistic risk still far off, Mosconi notes that simple tests such as those for eye movements or cognitive deficits could be used in the meantime to indicate a couple's risk of having an autistic child. And he and his colleagues are looking into shoring up the specificity of odds; some of the eye-movement patterns were specific to autism whereas others had similarities to other disorders, such as schizophrenia.
Although this study was relatively small and not designed to develop theories about disorder heritability risk and eye-movement abnormalities, Mosconi notes that potentially "there would be greater risk [of having a child with autism] if both parents are showing it."
But more research needs to be done to home in on how these patterns correlate with risk. And because not all of those with autism exhibit eye-movement abnormalities, it would not be a universal test. Nevertheless, eye and other cognitive exams are highly practical. "They're quick and sensitive tests, which is exciting," Mosconi says.
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10 Comments
Add CommentAutistic people don't process visual information the way NTs do.
Reply | Report Abuse | Link to thisBeing autistic, I can tell you that rapid focal shifting and smooth-pursuit are not as necessary when you have the processing power to let your gaze wander casually while cataloging everything that's happening in your field of view and synthesizing most of the details from data that comes from unfocused or peripheral vision.
In case anyone is wondering why one would want this, it leaves the visual focus and its data channels free to soak up every bit of information about what is actually interesting.
For each autistic person that's going to be different, but sacrificing unnecessary eye movements and the collection of data that can be easily deduced allows for processing data that is actually of benefit, or at least more interesting.
To NTs, each autistic person might as well have a completely different disease. You guys come at it like you're trying to hit a baseball.
Life is different for Autistics. It's just different. People who care enough to do experiments should be listening more and talking less.
Since Autism is usually diagnosed in childhood and was not widely diagnosed before around 1980, or 1992 for Asperger syndrome, perhaps the identified relatives could have exhibited additional Autism symptoms when younger, but have managed to better adapt socially as they matured.
Reply | Report Abuse | Link to thisAt any rate this 'diagnostic tool' has a significant potential for misidentification of possible risks for family planning and insurance purposes, since exhibition of the eye-movement 'deficits' do not definitively indicate any disorder.
The thought of future development of this test is scarily reminiscent of the science fiction movie "Blade Runner", which used a testing device to measure precise eye movements in response to stories about social behavior in order to identify cyborg 'Replicants' for 'termination'. Perhaps in an overpopulated future world suffering from resource shortages the 'normal' will detect the subtly 'deviant' for 'special treatment'. Not to be paranoid, or anything...
I really don't see why there is a connection here between autism in someone and an eye disorder among his/her relatives. The most you can infer is that there is a gene issue in question.
Reply | Report Abuse | Link to this-PTS
(www.parttimescholar.com)
Well, if they've found a correlation, I expect there is a correlation, but so what? Lots of people have autism to some degree or another, just as lots have hairy toes, short sight or big noses. As my mother was fond of saying when she felt I was being too sensitive about the behaviour of friends or siblings, "It takes all sorts to make a world," She was right - it does. Some of the great advances in science and technology have been made by backroom boys who were probably autistic. Square pegs just need square holes, we don't need to turn them into round pegs just to satisfy someone's idea of "normal".
Reply | Report Abuse | Link to thisI am more and more convinced that differences in visual perception are ignored early after diagnosis in favor of the popular 'tactile' theories. I am pleased to see more research attention to this - which could lead to less practice of ineffective interventions to make round the square. Not to be optimistic, or anything....
Reply | Report Abuse | Link to thisI am more and more convinced that differences with visual perception are not recognized early after diagnosis in favor of more popular theory surrounding 'tactile' issues. I am please to vision differences garnering more research attention - in the hope that ineffective treatment interventions will be fall away - not to be optimistic or anything....
Reply | Report Abuse | Link to thisIf a person with autism and his/her relatives share a trait with a genetic basis that may be important as part of the diagnostic picture, that undermines the contention that autism is acquired as a result of an external factor such as immunizations.
Reply | Report Abuse | Link to thisThat won't stop antivaxxers from blaming Thimerosal.
Reply | Report Abuse | Link to thisFor a study that was of only 57 ASD & 40 Norm patients, there seems no basis for using it "in the meantime" to tell **anyone** their "risks" for having a child on the autism spectrum! Especially since no report of the "norm" they used for *saying* it's so "rare"; Plus they admit the differences were so subtle that they would only show up with "very sensitive lab tests". So how normed can it be, if most folks wouldn't have had the tests as part of normal screening or tests in a medical setting? What years are we norming this "rare" difference on? Current populations or some small study long ago with a few added when they matched the suspected norm, say every decade or so? What percent of the world population is included in this "norm"? What "special populations" were the norm including or ignoring? I'd agree the study suggests more testing to see what comes of a broader base. However, it also seems that this article includes some pretty broad statements & proposed bad use of a very small study's results to me! And just as an additional show of eye contact non-norms, since my hearing is gotten worse as I aged, I watch folks lips to help lipread more than watching the eyes now, does that mean I've developed an eye tracking problem? LOL
Reply | Report Abuse | Link to thisDo the articles author(s) ever respond with more info to the comments and questions made here? I've seen responses in some "paper" magazines to reader comments. Does anyone know about online at Scientific American?
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