Featured Research

from universities, journals, and other organizations

New Method Of Scoring IQ Tests Benefits Children With Intellectual Disabilities

Date:
December 15, 2008
Source:
University of California - Davis - Health System
Summary:
Parents of children with intellectual disabilities have long been frustrated by intelligence quotient testing that tells them little to nothing about the long-term learning potential of their children.

Parents of children with intellectual disabilities have long been frustrated by intelligence quotient (IQ) testing that tells them little to nothing about the long-term learning potential of their children.

That's because these tests are scored according to the mean performance of children without disabilities. The result is that the raw scores of many children with intellectual disabilities are converted into the lowest normalized score, typically a zero.

"We send back these reports that don't tell parents anything about their child," explained David Hessl, an associate professor of clinical psychiatry and a researcher at the UC Davis M.I.N.D. Institute.

Hessl and a team of collaborators have devised a new system of scoring IQ tests taken by children with fragile X syndrome, a genetic disorder that causes intellectual disabilities, including autism. The details of the new method are described in a study published online today by the Journal of Neurodevelopmental Disorders.

"If this new method becomes widely available, we will be able to tell parents something more useful and more accurately diagnose and treat young children who are learning disabled," said Hessl, a physician who cares for children at the M.I.N.D. Institute with fragile X syndrome.

According to Hessl, there is a lot of meaningful variability in the performance of these children on IQ tests.

"We believe that this variability is important information about the relative strengths and weaknesses that these children have," Hessl explained. Frustrated by the lack of sensitivity of IQ tests, Hessl set out to devise a scoring method that would reveal the strengths and weaknesses of each child.

"I knew a more accurate estimation of the potential of these children would make a big difference in their lives," he said.

Hessl worked with fragile X researchers at the M.I.N.D. Institute and Stanford University, as well as a statistician from Pennsylvania State University. The team came up with new normalized scores for 217 children with fragile X syndrome who had undergone IQ testing.

Many of these children had normalized scores of 0 on the Wechsler Intelligence Scale for Children, an intelligence test for children between the ages of 6 and 16 that can be completed without reading or writing.

On the new scale, children scored as low as minus 10 on 14 subtests. These included verbal, arithmetic, picture completion and object assembly.

Like normalized scores of children without disabilities, the frequency of the new normalized scores for children with fragile X syndrome followed an expected, bell-shaped distribution.

"These new scores tell us more precisely how a child with fragile x syndrome deviates from the normal population in every sub-test area," Hessl said.

Physicians and parents also need to know that these new scores reflect something about the biology of the children.

So, the research team went on to compare the new normalized scores to a measure of adaptive behavior and a biological measure of the severity of fragile X syndrome. Without a normal copy of the fragile X gene, a vital protein (FMR1 protein, or FMRP) is not made and the result is the onset of characteristic mental disorders, which can range from learning disabilities to severe cognitive or intellectual disabilities, such as autism.

Hessl and his colleagues compared the levels of FMRP in blood from the test subjects to their new scores and found a significant correlation. They found similarly significant correlations between the IQ test scores and scores on the Vineland Adaptive Behavior Composite, which measures personal and social skills used in everyday living.

Treatment of fragile X syndrome depends on its manifestations in the individual, and range from behavioral therapy to medication. Widespread use of new normalized scores would allow physicians to better treat their patients, Hessl said.

Psychological Corporation, the publishers of the Wexler IQ test, gave permission for their raw date to be used in the context of research.

"I think we've made a good case for the makers of this test and others to release raw data to researchers so that this method can be applied to other populations with intellectual disabilities," Hessl said.

He is also hopeful that someday soon he will get permission to use his new scoring method when treating his patients. In the future, the publishers of IQ tests should include lower-functioning individuals in their standardization studies, Hessl said.

"This might mean over-sampling those with intellectual disability in order to get more sensitivity, but it would help so many children," he said.

Additional UC Davis researchers include M.I.N.D. Institute medical director Randi Hagerman; M.I.N.D Institute researcher Andrea Schneider; biochemistry and molecular medicine associate researcher Flora Tassone; and Danh Nguyen, associate adjunct professor of public health sciences. Other investigators included Damla Senturk of Pennsylvania State University, and Amy Lightbody, Allan Reiss and Scott Hall, all of Stanford University.


Story Source:

The above story is based on materials provided by University of California - Davis - Health System. Note: Materials may be edited for content and length.


Journal Reference:

  1. Hessl et al. A solution to limitations of cognitive testing in children with intellectual disabilities: the case of fragile X syndrome. Journal of Neurodevelopmental Disorders, 2008; DOI: 10.1007/s11689-008-9001-8

Cite This Page:

University of California - Davis - Health System. "New Method Of Scoring IQ Tests Benefits Children With Intellectual Disabilities." ScienceDaily. ScienceDaily, 15 December 2008. <www.sciencedaily.com/releases/2008/12/081215112701.htm>.
University of California - Davis - Health System. (2008, December 15). New Method Of Scoring IQ Tests Benefits Children With Intellectual Disabilities. ScienceDaily. Retrieved September 17, 2014 from www.sciencedaily.com/releases/2008/12/081215112701.htm
University of California - Davis - Health System. "New Method Of Scoring IQ Tests Benefits Children With Intellectual Disabilities." ScienceDaily. www.sciencedaily.com/releases/2008/12/081215112701.htm (accessed September 17, 2014).

Share This



More Mind & Brain News

Wednesday, September 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Corporal Punishment on Decline, Debate Renews

Corporal Punishment on Decline, Debate Renews

AP (Sep. 16, 2014) Corporal punishment in the United States is on the decline, but there is renewed debate over its use after Minnesota Vikings running back Adrian Peterson was charged with child abuse. (Sept. 16) Video provided by AP
Powered by NewsLook.com
FDA Eyes Skin Shocks Used at Mass. School

FDA Eyes Skin Shocks Used at Mass. School

AP (Sep. 15, 2014) The FDA is considering whether to ban devices used by the Judge Rotenberg Educational Center in Canton, Massachusetts, the only place in the country known to use electrical skin shocks as aversive conditioning for aggressive patients. (Sept. 15) Video provided by AP
Powered by NewsLook.com
Shocker: Journalists Are Utterly Addicted To Coffee

Shocker: Journalists Are Utterly Addicted To Coffee

Newsy (Sep. 13, 2014) A U.K. survey found that journalists consumed the most amount of coffee, but that's only the tip of the coffee-related statistics iceberg. Video provided by Newsy
Powered by NewsLook.com
'Magic Mushrooms' Could Help Smokers Quit

'Magic Mushrooms' Could Help Smokers Quit

Newsy (Sep. 11, 2014) In a small study, researchers found that the majority of long-time smokers quit after taking psilocybin pills and undergoing therapy sessions. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins