December 10, 2009

Brain Structure and Reading Ability and IQ

Intensive reading programs can produce measurable changes in the structure of a child's brain, according to a study in the journal Neuron. The study found that several different programs improved the integrity of fibers that carry information from one part of the brain to another.

They used a special type of MRI to look at the brains of several dozen children from 8 to 12 years old, including poor readers and those with typical reading skills. The MRI scans allowed the scientists to study the network of fibers that carries information around the brain, which lives in the brain's so-called white matter.

Children with poor reading skills had white matter with "lower structural quality" than typical children, Just says.

So during the next school year, Just and Keller enrolled some of the poor readers in programs that provided a total of 100 hours of intensive remedial instruction. The programs had the kids practice reading words and sentences over and over again.

When they were done, a second set of MRI scans showed that the training changed "not just their reading ability, but the tissues in their brain," Just says. The integrity of their white matter improved, while it was unchanged for children in standard classes.

Equally striking, Just says: "The amount of improvement in the white matter in an individual was correlated with that individual's improvement in his reading ability."

Having a good understanding of how brain structure effects learning and IQ could lead to improved training and possible pathways to transhuman cognitive enhancement or at least cognitive optimization.

Prior Brain Structure and IQ Studies

Research suggests that the layer of insulation coating neural wiring in the brain plays a critical role in determining intelligence. In addition, the quality of this insulation appears to be largely genetically determined, providing further support for the idea that IQ is partly inherited.

The neural wires that transmit electrical messages from cell to cell in the brain are coated with a fatty layer called myelin. Much like the insulation on an electrical wire, myelin stops current from leaking out of the wire and boosts the speed with which messages travel through the brain--the higher quality the myelin, the faster the messages travel. These myelin-coated tracts make up the brain's white matter, while the bodies of neural cells are called grey matter

Neuroanotomy and IQ at wikipedia

In 2004, Richard Haier, professor of psychology in the Department of Pediatrics and colleagues at University of California, Irvine and the University of New Mexico used MRI to obtain structural images of the brain in 47 normal adults who also took standard IQ tests. The study demonstrated that general human intelligence appears to be correlated with the volume and location of gray matter tissue in the brain. Although the regional distribution of gray matter in humans may have a genetic basis, structural changes can also occur in response to environmental stimulation. The study also demonstrated that, of the brain's gray matter, only about 6 percent appeared to be related to IQ.

A study involving 307 children (age between six to nineteen) measuring the size of brain structures using magnetic resonance imaging (MRI) and measuring verbal and non-verbal abilities has been conducted (Shaw et al. 2006). The study has indicated that there is a relationship between IQ and the structure of the cortex—the characteristic change being the group with the superior IQ scores starts with thinner cortex in the early age then becomes thicker than average by the late teens

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