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Down Syndrome: The Measure of Intelligence

20 Aug

What is considered intelligent varies with culture. For example, when asked to sort, the Kpelle people (a tribal ethnic group in Liberia and southern Guinea ) take a functional approach. A Kpelle participant stated “the knife goes with the orange because it cuts it.” When asked how a fool would sort, they sorted linguistically, putting the knife with other implements and the orange with other foods, which is the style considered intelligent in other cultures.

            Credit: Wikipedia: Glick (1975) reported in Resnick, L. (1976). The Nature of Intelligence. Hillsdale, New Jersey: Lawrence Erlbaum Associates. 

Here’s what this has to do with my 4-year-old son with Down syndrome:

Because of his genetic anomaly, Trisomy 21, which means possessing three copies of the 21st chromosome instead of two, my son and others like him have been deemed “intellectually disabled.” Or, a term that is thankfully falling out of favor even in medical circles, mentally retarded.

To come to this conclusion, researchers and psychologists have administered IQ tests that by and large are incapable of accurately determining the true abilities of people with Down syndrome. There are a number of reasons why they aren’t completely accurate, even though they may be the best tools available. But the most obvious is that they fail to take into account that people with Down syndrome cannot often easily express to others all that they know, either linguistically or through other means of communication. Their receptive language skills (the ability to receive and process information) are typically much stronger than their expressive language skills (their ability to give back).


Copyright © jaya vijayan, via Flickr

So if my son were to be given a similar sorting test to the one described in the opening, and if he were, say, to put an Elmo doll next to an Elephant because those are two of his most favorite things in the world, a researcher might deduct points. You see, Elmo goes with Big Bird and the Big Elephant goes with the Baby Elephant and that’s all there is to it. And anyway my son would not be able to explain about Elmos and Elephants being his favorites unless you were to ask directly, to which he would reply an enthusiastic “YES!”

So who is the fool in this scenario? (In one case, it was me. For proof, please check out this short post of mine, an all-time favorite.)

What if people whose brains differ from the norm aren’t deficient in intelligence, but they simply have a different kind of intelligence? What if they are just part of a different “tribe,” that adapts its intelligence to the world it is functioning within?

Why is this lady asking fanciful questions that cannot be resolved? Well, I do at least have an answer for that one.

You see, I have been inspired by a fellow blogger, Rebecca, over at The Bates Motel. She hosted a very well received blog hop last month asking writers and readers what they would like to see revealed, medically and scientifically speaking, about Down syndrome during their child’s lifetime.

My answer is two-fold:

First, I would like to see our culture become more open-minded about traditional intelligence, and to realize that there is beauty in the variability of intelligence. And to stop correlating the quality of a person’s “output” to his understanding of the world and to his essential worth. Some of the most fascinating people I have met are non-verbal or struggle with communication. My son is quite a talker, but he still falls into the latter category.

Second, I would like to see the development of cognitive tests that more accurately measure the strengths of people with Down syndrome. There will probably always be a need for testing, at least if a person with Down syndrome is going to be part of the school system or receive therapies or other interventions. Our son is not yet 5, so we haven’t been subjected to school-based IQ testing, but I am not looking forward to that day. I hate skill-based tests of any kind, because mostly they show how my son does not “measure up.” Testers often talk to parents with sternly sad eyes, peering down at you with all of their knowledge to deliver the “news” that your child’s scores are below what is normal for his age.

More to the point, these tests – any tests — fail to take into account our son’s quite sophisticated sense of humor and incredible memory for stories and songs. But I do realize that tests can have value, especially if they can measure whether a certain teaching approach or therapy is working to help him learn or to improve his memory. Like any parent, I want all of my children to learn how wonderful and complex the world is, and to retain that knowledge so they can add to it as they grow.

My wish for better testing, at least, may become a reality in my son’s lifetime. And even if he doesn’t benefit much from it, just the thought that it is happening, that dedicated scientists even care about this, makes me feel euphoric.

Through the magic of Google, I discovered that the Down Syndrome Research Group at the University of Arizona  is working on this very thing: cutting edge cognitive assessments. The research began a few years ago, and it was big news at that time, so I’m not the first to write about it. But I was curious about the status of the tests, so I contacted Professor Jamie Edgin, a developmental psychologist and one of the group’s lead researchers, and she agreed to an interview.

Basically, her group is developing tests that will piece together a “cognitive profile” specifically for Down syndrome, assessing skills across various domains like receptive and expressive language, memory, executive function and flexible thinking.  This can help us, Dr. Edgin said, look at “the peaks and valleys of where skills lie.” In general, she said, the problem with an IQ score is that it represents “an average score that doesn’t mean much.” So if specific skills can be more accurately measured, I asked her, then what does this mean, say, to a parent whose child with Down syndrome is in the school system?

“The idea is that IQ provides only a score that qualifies a student for services,” Dr. Edgin said. ”it does not help plan those services. To do so, an assessment must be made of individual skills in language, reading, numerical skills and ‘learning’ skills such as the ability to form associations between information and problem solving. Assessments that cover this range of outcomes will help teachers to discover strengths and areas of weakness. For instance, while a number of children with Down syndrome may have difficulty with expressive language, their receptive skills or problem solving ability might be stronger. If a teacher knows this information, the teaching plan could capitalize on the child’s problem solving strengths. An overall IQ score can’t tell you that. “

Down's Syndrome - school

© Richard Bailey, via Flickr

Collectively called the Arizona Cognitive Test Battery, these tests are administered to people with Down syndrome ages 11 to adulthood using a touch screen. The tests probably won’t be ready to use in school systems for several years, said Dr. Edgin, and that is assuming an agreement could be reached with a major testing company that would distribute them in schools. Right now, the tests are still in their first year of a five-year review process.

But the beauty of these tests is that they can be administered to people who are non-verbal or have limited verbal skills. Right there, this is a major departure and improvement upon traditional intelligence tests for school-age children, which rely heavily on verbal feedback. Dr. Edgin told me that some children who are non-verbal have completed the tests on the Arizona Cognitive Test Battery. “We’ve been able to tell that they can make connections between information and can show us this using a touch-screen computer,” she said, and the researchers are able to get a better understanding of their abilities without needing language.

Dr. Edgin also told me that some colleagues at the UC Davis Mind Institute in Sacramento, led by the institute’s director, Dr. Leonard Abbeduto, are working concurrently on assessments for people with Down syndrome ages 6 to 23 that analyze the structure and syntax of language but are conversational in nature and based around the lives and interests of the person taking the test. For instance, the interviewer will ask about pets and hobbies and other situations that are fresh in mind, Dr. Edgin said.

Traditional language assessments, for instance, “are not very well suited to individuals with intellectual disabilities,” Dr. Edgin said, because they require the test-taker to process a lot of information in a very short period of time and repeat back what someone else has said, which can be hard for people with Down syndrome because of working memory constraints.  People with Down syndrome are very sensitive to failure, Dr. Edgin said, and they often get stressed out on more traditional language assessments because they really want to do well but they may not understand what is being asked and cannot produce language quickly.

Dr. Edgin also made sure to point out that “IQ is just one measure” of functioning and that there are lots of different things that people with Down syndrome can do very well. Many, she said, “end up doing functionally really well and being integrated into the community” despite a lower IQ.

This resonated with me; I have always worked hardest on functional skills with our son, like teaching him to dress himself and use the potty, rather than on academics. Of course, now that summer is winding down, I’m realizing we might need to hit the books a little harder!

The Arizona test battery from Dr. Edgin’s group is currently being used in clinical research to help scientists understand the effectiveness of drug therapies to improve cognition. For instance, she said, Roche has a drug currently in adult clinical trials that lessons neural inhibition in the brains of people with Down syndrome, and the Arizona Cognitive Test Battery is being used there. (Neural inhibition prevents neural activity and the formation of new connections.)

The test battery is also being used in the Down Syndrome Cognition Project, a multi-site investigation of the genetic basis for the high degree of variation in cognitive ability among people with Down syndrome and alongside neuroimaging studies by Dr. Julie Korenberg  at the University of Utah.

What is striking about all of this, Dr. Edgin said, is that even five years ago, “there were lots of people who were hesitant to start work with this group,” meaning Down syndrome research, “because they were worried that many of the cognitive tests wouldn’t generate good data.”

“What we’re really proud of,” Dr. Edgin said, “is that our Arizona Battery tests show that you can in fact do this type of research, that there are ways to do it,” and measure progress. “We spent a lot of time putting out that message,” Dr. Edgin said, ”and now new people are starting to work in this field.”

Research into Down syndrome is a really “up-and-coming” area now, Dr. Edgin said. When she was in graduate school she began by studying autism but was very surprised by the lack of inquiry into the cognitive psychology of Down syndrome, so she switched her focus. Now, she said, the research that she and her colleagues nationwide are doing regarding cognitive testing has the potential to answer important questions that can have an immediate impact on people’s lives.

In fact, she said, this has already happened: data from the Arizona Test Battery helped a testing company that supplies some of the Arizona Battery measures to refine its methods to be targeted more effectively for people with Trisomy 21 and other intellectual disabilities.

“You don’t always have that kind of immediate impact in science,” she said. “It’s very rewarding.” She said that in refining testing procedures, her group has learned – and taught other clinicians – not only how to use the tests more effectively, but how to best work with people who have Down syndrome. In Dr. Edgin’s lab, the battery of tests is also being used to measure patterns of cognitive performance in relation to factors like obstructive sleep apnea, which occurs in at least 50 percent of people with Down syndrome and as many as 100 percent according to the National Down Syndrome Society.

Dr. Edgin’s team is also applying for a grant from the National Institutes of Health to fund an Arizona Memory Assessment for Preschoolers™ that would allow teachers to assess short- and long-term memory of students with Down syndrome using real objects and manipulatives. This would be at least six or seven years away from being put into use if the grant is awarded.

Throughout our conversation I got the very distinct sense that here was a person who truly cared about the “subjects” of her tests. She took great care to explain how the new tests would play to the strengths of people with Down syndrome and give a broader, more nuanced picture of their abilities. I never got the sense that she thought people with Down syndrome were in need of fixing, which is what we parents often worry that science wants to do to our children: either “fix” them, or eliminate others like them from the future population.

So I felt comfortable asking her a few philosophical questions about the scope and purpose of drug research. (For instance, Research Down Syndrome, which is supporting the work that Dr. Edgin’s group is doing, also finances inquiry into drug therapies to improve cognition and memory.) Questions about this have nagged at me, and I know they have for others too. Of course no one has definitive answers to such heavy questions, but I wanted an insight into the thinking of this particular scientist, who is on the front lines.

Parents worry, I told her, that all of this research into medicine to alter the brain functioning of people with Down syndrome is somehow aimed at changing them, because we worry that society does not appreciate them for who they already are.

“I can understand why they would worry about that,” Dr. Edgin said, “but at the end of the day, the drugs are unlikely to change who people with Down syndrome are, but they are trying to give them a boost. While findings from animals models show dramatic changes, in humans it is less likely we will see a radical change.” She compares this to parents she knows whose children take medication for ADHD. They were terrified at first, but found that it has simply given them a little help at school. “That’s probably what we’ll see with Down syndrome,” she said. “The drugs will give them a boost and allow them to take better advantage of therapies and other treatments.”

It’s one of those things, she went on, “that if a drug were to go through and be marketed, parents would have the option to try it. It may give their kid a boost, it may not. But we’ll never know if that boost is available to some children unless we go through the trial.” For example, some parents give their children a cocktail of vitamins in the hopes it will improve memory or cognitive functioning, and anecdotal success is reported but these supplements have not undergone clinical trials. Going through the whole process to get a drug that is regulated by the FDA, she said, is much more effective than having lots of different supplements that are not tested for efficacy or unregulated.

As for me, I’m not sure I’d be jumping up and down at the chance to give my son a medicine that may provide a “brain boost.” As things stand right now, he’s doing great, but I’m aware that his need for complex thinking will only grow as he gets older. I imagine by the time such drugs are thoroughly tested and approved for use, my son will be a teenager or nearly so, and we’ll have a family discussion about it then. But all this is not about me, or him. It’s about the entire Down syndrome population, and some families may welcome this option, so I am heartened to know this is an avenue of research.

One other thing I was curious about: Is Dr. Edgin concerned that the recent development of prenatal tests to screen for Down syndrome at very early stages of pregnancy, thus potentially making it easier for women to choose abortion, will make the need for Down syndrome research obsolete?

“At the end of the day, it takes a while for these things to be implemented,” she said, meaning the rollout and usage of the new prenatal tests, the effects of which it is still too early to determine.

“It is possible that the population will be less,” she said, “but it’s not a rare disorder. And anyway, there are all the people now who have Down syndrome and we have an obligation to help them.”

“I can see why people might be concerned,” she said, “but from my perspective, it’s not an issue I’m worried about. There will be work to do and I’m going to do it.”


Thoroughly Modern Messy receives nothing in exchange for talking about Dr. Edgin’s work; this post is meant only to inform. Funding for the Arizona Cognitive Test Battery is provided by the Down Syndrome Research and Treatment Foundation, Research Down Syndrome, the Arizona Alzheimer’s Research Consortium and the Anna and John J. Sie Foundation. “But, we are seeking funds at the University of Arizona for our work, including the gift of a chaired professorship for me so I might be able to build our research and training program in Arizona and see many of these projects through to completion,“ Dr. Edgin said. For more information on what her group is working on, click here.