News reports of research into memory September 2007

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September 2007

Insufficient sleep in early childhood associated with developmental delay

A long-term study of nearly 1500 young children (from 5 months to six years) found four sleep duration patterns; 6% slept less than 10 hours per night throughout early childhood, and 4.8% did so until around 41 months, when it increased. Short sleep duration was found to significantly increase the risk of low performance on the Peabody Picture Vocabulary Test–Revised (given at 5 years), suggesting that language acquisition and the consolidation of new words into memory could be significantly impeded by chronically shortened sleep duration throughout childhood. An increased risk of poorer performance on the Block Design subtest (given at 6 years) was also evident even among those who had increased their sleep duration, suggesting that there is a critical period in early childhood where the lack of sleep is particularly detrimental on various aspects of development even if the sleep duration normalizes later on.
The study was published in the September 1 issue of SLEEP. Full reference
http://www.eurekalert.org/pub_releases/2007-09/aaos-jsl082407.php

Right breakfast bread keeps blood sugar in check all day

A doctoral study has found that those given low glycemic index breakfasts could concentrate better and had a better working memory. Moreover, healthy individuals with low glucose tolerance (higher than average rises in blood sugar following a meal) generally performed less well. The study also found that eating the right whole-grains for breakfast didn’t simply regulate blood-sugar levels all morning, but all day — some ten hours. Experiments also showed that the blood sugar increase following breakfast can be moderated in a similar way by eating the right grain products the night before. Great variations in levels of blood sugar are being associated more and more with the risk of old-age diabetes, obesity, and cardiovascular diseases. Full reference
http://www.eurekalert.org/pub_releases/2007-09/src-rbb090507.php

Eye movement can affect problem-solving

Following on from a 2003 study that found that certain patterns of eye movement occurred as participants got closer to solving a problem, researchers have influenced the chances of success at solving a problem by occasionally guiding the eye movements of participants with an unrelated tracking task, suggesting that not only does eye movement reflect thought, but that what you’re thinking can be affected by how you move your eyes. The researchers speculate that initiating these eye movements triggers a perceptual simulation of how to solve the problem.
The report appeared in the August issue of Psychonomic Bulletin and Review. Full reference
http://www.eurekalert.org/pub_releases/2007-09/uoia-rfe092407.php

Possible genetic risk for fetal alcohol disorders

In partial explanation of why children who are exposed to alcohol because their mothers drank during pregnancy are differently affected, new research with rhesus monkeys has found evidence of a gene variant that appears to make the carrier more susceptible to the effects of fetal alcohol exposure. The gene involved is the serotonin transporter gene promoter, and this variant has previously been implicated in increased depression risk.
The findings were reported online September 21 in Biological Psychiatry. Full reference
http://www.eurekalert.org/pub_releases/2007-09/uow-srp092107.php

Fundamental defect in fragile X syndrome identified and corrected

In an exciting new cell study, scientists have not only discovered the fundamental defect that causes fragile X syndrome (the most common inherited form of mental retardation), but also how to correct the problem. It is hoped that this will eventually lead to the development of human therapies for this previously untreatable condition.
The findings were reported online September 19 in the Proceedings of the National Academy of Sciences. Full reference
http://www.eurekalert.org/pub_releases/2007-09/eu-sif091307.php

Memory tasks require more coordinated brain blood flow for people with high blood pressure

Previous studies have found an association between high blood pressure and cognitive decline in older adults, but the evidence hasn’t been entirely consistent. Now a new study helps explain why the situation is not entirely straightforward. It appears that people with high blood pressure required more blood flow to the parts of the brain that support memory function than those with normal blood pressure. Moreover, and surprisingly, it turned out that antihypertensive medication actually made it worse, increasing the inefficiency of the brain’s work during memory tasks.
The findings were reported at the American Heart Association’s 61st Annual Fall Conference of the Council for High Blood Pressure Research.
http://www.eurekalert.org/pub_releases/2007-09/aha-mtr092707.php

Combined hormone therapy doesn't boost memory

A study of 180 recently menopausal women found no effect of hormone therapy (a combination of estrogen and progesterone) on cognitive function. Previous research has indicated a positive benefit of estrogen on cognition, so it is speculated that progestin may counteract these positive effects.
The study appeared in the September 25 issue of Neurology. Full reference
http://www.eurekalert.org/pub_releases/2007-09/aaon-hti091807.php

Obesity in old age not associated with memory problems

A six-year study involving 3,885 older adults (over 65) found that, despite obesity contributing to high blood pressure, heart disease and diabetes, it was not associated with memory problems. In fact, participants who were underweight had more cognitive decline over time. Previous studies have found suggestions that losing weight is correlated with developing Alzheimer’s (but obesity in middle age is associated with an increased risk of dementia). Of the participants, nearly 25% were obese, and 37% overweight.
The study was published online September 19 in Neurology. Full reference
http://www.eurekalert.org/pub_releases/2007-09/aaon-dbo091807.php

Playing video games reduces sex differences in spatial skills

A new study has pinpointed one factor in why women tend to be poorer than men at spatial tasks — they tend not to be quite as good at rapidly switching attention among different objects. But ten hours of playing action video games virtually eliminated this gender difference (there was no improvement in those playing a non-action game), and also improved the women’s mental rotation skills. Moreover, this improvement was still there five months later.
The research was published in the October issue of Psychological Science. Full reference
http://www.physorg.com/news110203374.html

Brain network related to intelligence identified

A review of 37 imaging studies may have finally answered an age-old question: where is intelligence. Following on from recent evidence suggesting that intelligence is related to how well information travels throughout the brain, the researchers believe they have identified the stations along the routes intelligent information processing takes. These stations primarily involve areas in the frontal and the parietal lobes, many of which are involved in attention and memory, and more complex functions such as language. Basically, the researchers theorize that your level of intelligence is a function of how well these areas communicate with each other. It’s particularly interesting to note that these various imaging studies had remarkably consistent results despite the different definitions of intelligence used in them.
The review appeared in Behavioral and Brain Sciences. Full reference
http://www.physorg.com/news108722746.html
http://www.eurekalert.org/pub_releases/2007-09/uoc--bnr091007.php
http://www.livescience.com/health/070911_intel_network.html

Having right timing 'connections' in brain is key to overcoming dyslexia

New research has found that key areas for language and working memory involved in reading are connected differently in dyslexics than in children who are good readers and spellers. But, after the children with dyslexia went through a three-week instructional program, their patterns of functional brain connectivity normalized and were similar to those of good readers. The study looked specifically at activity in the left and right inferior front gyrus. The left inferior front gyrus may control the communication between the different areas involved in language, especially spoken language, while the right is thought to be involved in controlling the processing of letters in written words. Prior to the treatment these two areas were overconnected in the dyslexics, and the left inferior frontal gyrus also was overconnected to the middle frontal gyrus, which is involved in working memory that requires temporal coordination. It is not yet known how long the improvement in connectivity is maintained.
The study was published online August 17 in the Journal of Neurolinguistics. Full reference
http://www.eurekalert.org/pub_releases/2007-09/uow-hrt090407.php
http://www.sciencedirect.com/science/journal/09116044

Why music training helps language

Several studies have come out in recent years suggesting that giving children music training can improve their language skills. A new study supports these findings by showing how. The latest study shows that music triggers changes in the brain stem, a very early stage in the processing pathway for both music and language. It has previously been thought that the automatic processing occurring at this level was not particularly malleable, and the strength of neuron connections there was fixed.

And in another study, researchers have found evidence for more commonality in the brain networks involved in music and language. One network, based in the temporal lobes, helps us memorize information in both language and music— for example, words and meanings in language and familiar melodies in music. The other network, based in the frontal lobes, helps us unconsciously learn and use the rules that underlie both language and music, such as the rules of syntax in sentences, and the rules of harmony in music.

The first report appeared online September 24 in Proceedings of the National Academy of Sciences USA. Full reference
The second appeared online ahead of print in NeuroImage. Full reference
http://www.sciam.com/article.cfm?chanID=sa003&articleID=39568C58-E7F2-99DF-32A49429C2B356CD&sc=WR_20071002 (1^st)
http://www.sciencedaily.com/releases/2007/09/070926123908.htm (1^st)
http://www.eurekalert.org/pub_releases/2007-09/gumc-tat092707.php (2^nd)