Gray matter: Research reports

news items

Changes in gray matter induced by learning

Three months of training in three-ball cascade juggling was found to be associated with a transient and highly selective increase in gray matter in the occipito-temporal cortex. A follow-up study involving 20 adults confirmed this finding and found that the change in grey matter occurred after only 7 days of training. Neither performance nor exercise alone could explain these changes, and the increase receded when training stopped. The researchers suggest that learning a new task is more critical for the brain to change its structure than continued training of an already-learned task.
The report appeared July 23 in the open access journal PLoS One.  Full reference
http://www.plosone.org/article/info:doi/10.1371/journal.pone.0002669

IQ-related brain areas may differ in men and women

An imaging study of 48 men and women between 18 and 84 years old found that, although men and women performed equally on the IQ tests, the brain structures involved in intelligence appeared distinct. Compared with women, men had more than six times the amount of intelligence-related gray matter, while women had about nine times more white matter involved in intelligence than men did. Women also had a large proportion of their IQ-related brain matter (86% of white and 84% of gray) concentrated in the frontal lobes, while men had 90% of their IQ-related gray matter distributed equally between the frontal lobes and the parietal lobes, and 82% of their IQ-related white matter in the temporal lobes. The implications of all this are not clear, but it is worth noting that the volume of gray matter can increase with learning, and is thus a product of environment as well as genes. The findings also demonstrate that no single neuroanatomical structure determines general intelligence and that different types of brain designs are capable of producing equivalent intellectual performance.
The study was published online January 16 in NeuroImage. Full reference
http://health.yahoo.com/news/57792
http://www.eurekalert.org/pub_releases/2005-01/uoc--iim012005.htm
http://www.sciencedaily.com/releases/2005/01/050121100142.htm

Chronic back pain shrinks 'thinking parts' of the brain

A new study has found chronic back pain shrinks the brain by as much as 11% — equivalent to the amount of gray matter lost in 10 to 20 years of normal aging. Loss in brain density is related to pain duration, indicating that 1.3 cubic centimeters of gray matter are lost for every year of chronic pain. The study compared 26 participants with chronic back pain for more than a year with matched normal subjects.
The study was published in the November 17 issue of The Journal of Neuroscience. Full reference
http://www.eurekalert.org/pub_releases/2004-11/nu-cbp111504.htm

Intelligence based on the volume of gray matter in certain brain regions

Confirming earlier suggestions, the most comprehensive structural brain-scan study of intelligence to date supports an association between general intelligence and the volume of gray matter tissue in certain regions of the brain. Because these regions are located throughout the brain, a single "intelligence center" is unlikely. It is likely that a person's mental strengths and weaknesses depend in large part on the individual pattern of gray matter across his or her brain. Although gray matter amounts are vital to intelligence levels, only about 6% of the brain’s gray matter appears related to IQ — intelligence seems related to an efficient use of relatively few structures. The structures that are important for intelligence are the same ones implicated in memory, attention and language. There are also age differences: in middle age, more of the frontal and parietal lobes are related to IQ; less frontal and more temporal areas are related to IQ in the younger adults. Previous research has shown the regional distribution of gray matter in humans is highly heritable. The findings also challenge the recent view that intelligence may be a reflection of more subtle characteristics of the brain, such as the speed at which nerve impulses travel in the brain, or the number of neuronal connections present. It may of course be that all of these are factors.
The study appears in the online edition of NeuroImage. Full reference
http://www.sciencedaily.com/releases/2004/07/040720090419.htm
http://www.eurekalert.org/pub_releases/2004-07/uoc--hid071904.htm

Growing evidence cerebellum involved in language

An imaging study of children with selective problems in short term phonological memory and others diagnosed with specific language impairment (and matched controls) found that those with selective STPM deficits and those with SLI had less gray matter in both sides of the cerebellum compared to the children in the control groups. This supports growing evidence that the cerebellum, an area of the brain once thought to be involved only in the control of movement, also plays a role in processing speech and language.
http://www.eurekalert.org/pub_releases/2003-11/sfn-ssb111103.htm

Maturation of the human brain mapped

The progressive maturation of the human brain in childhood and adolescence has now been mapped. The initial overproduction of synapses in the gray matter that occurs after birth, is followed, for the most part just before puberty, with their systematic pruning. The mapping has confirmed that this maturation process occurs in different regions at different times, and has found that the normal gray matter loss begins first in the motor and sensory parts of the brain, and then slowly spreads downwards and forwards, to areas involved in spatial orientation, speech and language development, and attention (upper and lower parietal lobes), then to the areas involved in executive functioning, attention or motor coordination (frontal lobes), and finally to the areas that integrate these functions (temporal lobe). "The surprising thing is that the sequence in which the cortex matures appears to agree with regionally relevant milestones in cognitive development, and also reflects the evolutionary sequence in which brain regions were formed."
http://www.eurekalert.org/pub_releases/2003-11/sfn-smm110803.htm

Imaging study confirms link between exercise and cognitive function

A number of studies have suggested a link between exercise and cognitive function in older adults, but now an imaging study shows that there are actual anatomical differences in the brains of physically fit versus less fit older adults (over 55). Specifically, they found very distinct differences in the gray and white matter in the frontal, temporal, and parietal cortexes. With aging, these tissues shrink, a reduction closely matched by declines in cognitive performance. Fitness, it appears, slows that decline. A related study, published in March, suggests that women may benefit more from exercise than men.
The report appeared in the February issue of the Journal of Gerontology: Medical Sciences. Full reference
http://www.eurekalert.org/pub_releases/2003-01/uoia-sif012703.htm

More grey matter in the auditory cortex of musicians' brains

New research augments earlier findings concerning the amount and distribution of gray matter in the brains of professional musicians. It now appears that musicians also have an increased volume of grey matter in the Broca's area, an area of the brain involved in the production of language. A critical factor appears to be the number of years devoted to musical training - at least for musicians under the age of 50. The research supports recent suggestions that musicians process music like an additional language.
The findings were published in the November issue of NeuroImage. Full reference
http://news.bmn.com/news/story?day=021031&story=1

Significant brain differences between professional musicians trained at an early age and non-musicians

Research has revealed significant differences in the gray matter distribution between professional musicians trained at an early age and non-musicians. It is most likely that this is due to intensive musical training at an early age, although it is also possible that the musicians were born with these differences, which led them to pursue musical training.
The study was presented at the American Academy of Neurology's 53rd Annual Meeting in Philadelphia, PA Reference
http://www.eurekalert.org/pub_releases/2001-05/AAoN-Mtdc-0705101.htm

Calculation difficulties in children of very low birthweight

Learning difficulties, including problems with numeracy, are common in Western populations. Many children with learning difficulty are survivors of preterm birth. Although some of these children have neurological disabilities, many are neurologically normal. A neuroimaging study of neurologically normal adolescent children who had been born preterm at 30 weeks gestation or less found an area in the left parietal lobe where children without a deficit in calculation ability have more grey matter than those who do have this deficit.
The study appeared in Brain. Full reference
http://brain.oupjournals.org/cgi/content/abstract/124/9/1701
http://news.bbc.co.uk/hi/english/sci/tech/newsid_1512000/1512664.stm
http://www.independent.co.uk/story.jsp?story=90945 http://www.independent.co.uk/story.jsp?story=90945 http://www.independent.co.uk/story.jsp?story=90945

Gray matter may decline from adolescence, but white matter keeps growing until our late forties

Brain scans of 70 men, ages 19 to 76 confirms that the brain's gray matter, the cell bodies of nerve cells, declines steadily from adolescence. But surprisingly, the white matter, the fatty material that insulates the long extending branches of the nerve cells and makes nerve signals move faster, in the frontal parts of the brain appears to grow at least until the late 40's, before beginning to decline. The growth of white matter may improve the brain's ability to process information.
The study, from the Department of Veterans Affairs, appears in the May issue of The Archives of General Psychiatry. Full reference
http://www.nytimes.com/2001/05/22/health/22VITA-3.html

A large-scale study of mental abilities in adults found that mental faculties were unchanged until the mid-40s, when a marked decline began and continued at a constant rate. The ability to remember words after a delay was especially affected. Accuracy did not seem to be affected, only speed.
The paper was presented to a British Psychological Society conference in London.
Guardian report