Featured Research

from universities, journals, and other organizations

Cortex Matures Faster In Youth With Highest IQ

Date:
March 30, 2006
Source:
NIH/National Institute Of Mental Health
Summary:
Youth with superior IQ are distinguished by how fast the thinking part of their brains thickens and thins as they grow up, researchers at the National Institutes of Health's (NIH) National Institute of Mental Health (NIMH) have discovered. Magnetic resonance imaging (MRI) scans showed that their brain's outer mantle, or cortex, thickens more rapidly during childhood, reaching its peak later than in their peers -- perhaps reflecting a longer developmental window for high-level thinking circuitry.

The developmental trajectory of waxing and waning in cortex thickness differs as the brain matures in different IQ groups. Thickness of the area at the top/front/center, highlighted in MRI brain maps at left, peaks relatively late, at age 12 (blue arrow), in youth with superior intelligence, perhaps reflecting an extended critical period for development of high-level cognitive circuits. (Source: NIMH Child Psychiatry Branch)

Youth with superior IQ are distinguished by how fast the thinking part of their brains thickens and thins as they grow up, researchers at the National Institutes of Health's (NIH) National Institute of Mental Health (NIMH) have discovered. Magnetic resonance imaging (MRI) scans showed that their brain's outer mantle, or cortex, thickens more rapidly during childhood, reaching its peak later than in their peers — perhaps reflecting a longer developmental window for high-level thinking circuitry. It also thins faster during the late teens, likely due to the withering of unused neural connections as the brain streamlines its operations. Drs. Philip Shaw, Judith Rapoport, Jay Giedd and colleagues at NIMH and McGill University report on their findings in the March 30, 2006 issue of Nature.

"Studies of brains have taught us that people with higher IQs do not have larger brains. Thanks to brain imaging technology, we can now see that the difference may be in the way the brain develops," said NIH Director Elias A. Zerhouni, M.D.

While most previous MRI studies of brain development compared data from different children at different ages, the NIMH study sought to control for individual variation in brain structure by following the same 307 children and teens, ages 5-19, as they grew up. Most were scanned two or more times, at two-year intervals. The resulting scans were divided into three equal groups and analyzed based on IQ test scores: superior (121-145), high (109-120), and average (83-108).

The researchers found that the relationship between cortex thickness and IQ varied with age, particularly in the prefrontal cortex, seat of abstract reasoning, planning, and other "executive" functions. The smartest 7-year-olds tended to start out with a relatively thinner cortex that thickened rapidly, peaking by age 11 or 12 before thinning. In their peers with average IQ, an initially thicker cortex peaked by age 8, with gradual thinning thereafter. Those in the high range showed an intermediate trajectory (see below). While the cortex was thinning in all groups by the teen years, the superior group showed the highest rates of change.

"Brainy children are not cleverer solely by virtue of having more or less gray matter at any one age," explained Rapoport. "Rather, IQ is related to the dynamics of cortex maturation."

The observed differences are consistent with findings from functional magnetic resonance imaging, showing that levels of activation in prefrontal areas correlates with IQ, note the researchers. They suggest that the prolonged thickening of prefrontal cortex in children with superior IQs might reflect an "extended critical period for development of high-level cognitive circuits." Although it's not known for certain what underlies the thinning phase, evidence suggests it likely reflects "use-it-or-lose-it" pruning of brain cells, neurons, and their connections as the brain matures and becomes more efficient during the teen years.

"People with very agile minds tend to have a very agile cortex," said Shaw. The NIMH researchers are following-up with a search for gene variants that might be linked to the newly discovered trajectories. However, Shaw notes mounting evidence suggesting that the effects of genes often depends on interactions with environmental events, so the determinants of intelligence will likely prove to be a very complex mix of nature and nurture.

Also participating in the study were Drs. Dede Greenstein, Liv Clasen, Rhoshel Lenroot, and Nitin Gogtay, Child Psychiatry Branch, NIMH; and Drs. Jason Lerch and Alan Evans, Montreal Neurological Institute, McGill University.


Story Source:

The above story is based on materials provided by NIH/National Institute Of Mental Health. Note: Materials may be edited for content and length.


Cite This Page:

NIH/National Institute Of Mental Health. "Cortex Matures Faster In Youth With Highest IQ." ScienceDaily. ScienceDaily, 30 March 2006. <www.sciencedaily.com/releases/2006/03/060330083935.htm>.
NIH/National Institute Of Mental Health. (2006, March 30). Cortex Matures Faster In Youth With Highest IQ. ScienceDaily. Retrieved September 18, 2014 from www.sciencedaily.com/releases/2006/03/060330083935.htm
NIH/National Institute Of Mental Health. "Cortex Matures Faster In Youth With Highest IQ." ScienceDaily. www.sciencedaily.com/releases/2006/03/060330083935.htm (accessed September 18, 2014).

Share This



More Mind & Brain News

Thursday, September 18, 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