Navigation Links
New evidence confirms link between IQ and brain cortex
Date:3/4/2014

Rate of change in the thickness of the brain's cortex is an important factor associated with a person's change in IQ, according to a collaborative study by scientists in five countries including researchers at the Montreal Neurological Institute and Hospital The Neuro, at McGill University and the McGill University Health Centre. The study has potentially wide-ranging implications for the pedagogical world and for judicial cases in which the defendant's IQ score could play a role in determining the severity of the sentence.

The cortex is the thin, outermost layer of nerve cell tissue of the brain, typically measuring a few millimeters in thickness. The cortex contains nerve cell bodies and is critical for cognitive functions such as perception, language, memory and consciousness.

"Often, small differences in IQ scores are observed when people's IQs are tested twice over a period of time. However, in some instances, dramatic changes in IQ scores are observed," said Dr. Sherif Karama, assistant professor of psychiatry at McGill University, psychiatrist at Douglas Mental Health University Institute and affiliate at The Neuro where he conducted the study published in the scientific journal, Neuro Image. "These dramatic changes are generally attributed to measurement errors rather than assumed to reflect real changes in general cognitive ability."

The cortex begins to thin after the age of five or six as part of the normal aging process. This study by Professor Karama and his colleagues involved 188 children and adolescents over a period of two years. MRIs of the study participants were taken at six sites across the US. This study is the first to show the association between cortical thickness and development in full scale IQ. They found that within a relatively short period of 2 years:

  • people with a significant increase in IQ did not have the expected cortical thinning,
  • people whose IQ stayed the same had the normal expected cortical thinning,
  • people with a significant decrease in IQ had exaggerated cortical thinning.

"Finding that IQ is not fixed and correlates to changes in brain anatomy has important implications as it shows that some of the changes in IQ are real and not merely due to measurement error. This finding should make people wary of sticking to an early IQ assessment given the role it plays in school entrance criteria, detection of the gifted, as well as in eligibility for social security disability income or even the death penalty. In some US states, people with an IQ below 70 are not eligible for the death penalty."

The reasons behind the changes in IQ are not clear at this point. Some of these may be due to programmed developmental trajectories or other factors such as nutrition and education, noted Professor Karama.


'/>"/>

Contact: Anita Kar
anita.kar@mcgill.ca
514-398-3376
McGill University
Source:Eurekalert

Related biology news :

1. Research reveals first evidence of hunting by prehistoric Ohioans
2. Strong scientific evidence that eating berries benefits the brain
3. UNH research adds to mounting evidence against popular pavement sealcoat
4. NIST/UMass study finds evidence nanoparticles may increase plant DNA damage
5. Evidence shows that anti-depressants likely do more harm than good, researchers find
6. Evidence of familial vulnerability for epilepsy and psychosis
7. New evidence that many genes of small effect influence economic decisions and political attitudes
8. DNA evidence shows that marine reserves help to sustain fisheries
9. New evidence in fructose debate: Could it be healthy for us?
10. Study provides first evidence of coevolution between invasive, native species
11. First direct evidence that elemental fluorine occurs in nature
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:2/2/2016)... RESTON, Va. , Feb. 2, 2016 /PRNewswire/ ... contract award from the U.S. Army Research Office ... extend the range and sensitivity of the company,s ... DoD,s Past Accounting Mission and, more generally, defense-related ... its DNA phenotyping capabilities (predicting appearance and ancestry ...
(Date:2/1/2016)... NEW YORK , Feb. 1, 2016  Today, ... Heart Association (AHA) announced plans to develop a first ... cognitive computing power of IBM Watson. In the first ... disease, AHA, IBM (NYSE: IBM ), and Welltok ... metrics and health assessments with cognitive analytics, delivered on ...
(Date:1/27/2016)... 2016  Rite Track, Inc. a leading semiconductor equipment ... Chester, Ohio announced today the acquisition of PLUS ... in Austin, Texas , will significantly ... modifications, installations and technical support offerings for TEL Track ... commented, "PLUS has provided world class service including refurbishment, ...
Breaking Biology News(10 mins):
(Date:2/12/2016)... , February 12, 2016 ... Efforts by Enabling Scientific Understanding of Complex Diseases ... Rare Diseases --> ... diagnostics in South Asia and a leading provider of ... contribute $10 million to the GenomeAsia 100K consortium ...
(Date:2/11/2016)... Germany and GERMANTOWN, ... QGEN ; Frankfurt Prime Standard: QIA) today announced ... RNA Panels for gene expression profiling, expanding QIAGEN,s portfolio ... The panels enable researchers to select from over 20,000 ... and discover interactions between genes, cellular phenotypes and disease ...
(Date:2/11/2016)... ... February 11, 2016 , ... ... cutting-edge information focused on the development and manufacture of biopharmaceuticals and therapeutics, ... sponsor of the 2016 BioProcess International Awards – Recognizing Excellence in the ...
(Date:2/11/2016)... ... February 11, 2016 , ... ... than 150 years, continues today to pursue the highest level of accuracy and ... instruments: the AR9 Refractometer and the AR5 Refractometer. Accurate, reliable and tough ...
Breaking Biology Technology: