Children

Children's learning & development

Mathematics

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Dyscalculia

Older news items (pre-2010) brought over from the old website

Factors influencing math performance

Early math skills best predict school success

A review of data from six studies of close to 36,000 preschoolers has revealed that the single most important factor in predicting later academic achievement is that children begin school with a mastery of early math and literacy concepts. This was true even if they have various social and emotional problems. Children's attention-related skills also mattered. The very strongest predictor of future academic success was beginning school with a knowledge of numbers, number order and other rudimentary math concepts. The study controlled for IQ, family income, gender, temperament, type of previous educational experience, and whether children came from single or two parent families. Mastery of early math skills predicted future reading achievement as well as future math achievement. The opposite was not true.

Duncan, G.J. et al. 2007. School Readiness and Later Achievement. Developmental Psychology, 43 (6), 1428–1446. 

http://www.sciencedaily.com/releases/2007/11/071112182442.htm

Gesturing helps grade-schoolers solve math problems

Two studies of children in late third and early fourth grade, who made mistakes in solving math problems, have found that children told to move their hands when explaining how they’d solve a problem were four times as likely as kids given no instructions to manually express correct new ways to solve problems. Even though they didn’t give the right answer, their gestures revealed an implicit knowledge of mathematical ideas, and the second study showed that gesturing set them up to benefit from subsequent instruction. The findings extend previous research that body movement not only helps people to express things they may not be able to verbally articulate, but actually to think better.

Broaders, S.C., Cook, S.W., Mitchell, Z. & Goldin-Meadow, S. 2007. Making Children Gesture Brings Out Implicit Knowledge and Leads to Learning. Journal of Experimental Psychology: General, 136 (4).

http://www.eurekalert.org/pub_releases/2007-11/apa-ghg102907.php

Young children can add and subtract without arithmetic

We knew infants can judge simple mathematical relationships, such as being able to tell when there are more objects in one group compared to another. Now a new study shows that children can apply that ability to Arabic numerals after learning to count but before they learned to add and subtract. When given such problems as, "Sarah has 15 candies and she gets 19 more; John has 51 candies. Who has more?", five- and six-year-old children answered correctly 64—73% of the time. The research suggests ways to improve children’s engagement with formal arithmetic.

Gilmore, C.K., McCarthy, S.E. & Spelke, E.S. 2007. Symbolic arithmetic knowledge without instruction. Nature, 447, 589-591.

Executive function as important as IQ for math success

A study of 141 preschoolers from low-income homes has found that a child whose IQ and executive functioning were both above average was three times more likely to succeed in math than a child who simply had a high IQ. The parts of executive function that appear to be particularly linked to math ability in preschoolers are working memory and inhibitory control. In this context, working memory may be thought of as the ability to keep information or rules in mind while performing mental tasks. Inhibitory control is the ability to halt automatic impulses and focus on the problem at hand. Inhibitory control was also important for reading ability. The finding offers the hope that training to improve executive function will improve academic performance

Blair, C. & Razza, R.P. 2007. Relating Effortful Control, Executive Function, and False Belief Understanding to Emerging Math and Literacy Ability in Kindergarten. Child Development, 78 (2), 647–663.

Language affects how math is done?

A comparison of activity in the brains of Chinese and English participants doing simple arithmetic using Arabic numbers has found that, although both groups utilised the inferior parietal cortex (an area connected to quantity representation and reading), English speakers displayed more activity in the language processing area of the brain, while Chinese speakers used the area of the brain that deals with processing visual information. There was no significant difference in the reaction time and accuracy of the Chinese and English-speaking volunteers. However, an earlier study comparing Canadian and Chinese students found that the latter were better at complex maths. The findings suggest that our native language, or different teaching methods, may influence the way we solve equations.

Tang, Y. et al. 2006. Arithmetic processing in the brain shaped by cultures. Proc. Natl. Acad. Sci. USA, Published online before print June 30, 2006.

 http://www.newscientist.com/article/dn9422?DCMP=NLC-nletter&nsref=dn9422

Preschool storytelling ability linked to later mathematical ability

A new study suggests that preschool children's early storytelling abilities are predictive of their mathematical ability two years later. In the study, three-and four-year-old children were shown a book that contained only pictures and were asked to tell the story to a puppet. Their abilities were measured in a variety of ways. Two years later, the children were given a number of tests of academic achievement, including a test of mathematical achievement. It was found was that those children who scored highly on the mathematics test had also scored highly on certain measures of their storytelling ability two years earlier. "Most strongly predictive of children's mathematical performance was their ability to relate all the different events in the story, to shift clearly from the actions of one character to another, and to adopt the perspective of different characters and talk about what they were feeling or thinking." This study suggests that building strong storytelling skills early in the preschool years may be helpful in preparing children for learning mathematics when they enter school.

O’Neill, D.K. et al. 2004. Preschool children's narratives and performance on the Peabody Individualized Achievement Test - Revised: Evidence of a relation between early narrative and later mathematical ability. First Language, 24 (2), 149-184.

http://www.eurekalert.org/pub_releases/2004-07/nsae-url072904.php

Factors impairing math ability

Gender gap in math is culture-based

Data from the Trends in International Mathematics and Science Study and the Programme for International Student Assessment, representing 493,495 students ages 14-16 from 69 countries, have revealed only very small gender differences overall, but marked variation when nations are compared. For example, there are more girls in the top tier in countries such as Iceland, Thailand, and the United Kingdom–and even in certain U.S. populations, such as Asian-Americans. However, despite overall similarities in math skills, boys felt significantly more confident in their abilities than girls did and were more motivated to do well. Furthermore, although some studies have found more males than females scoring above the 95th or 99th percentile, this gender gap has significantly narrowed over time in the U.S. and is not found among some ethnic groups and in some nations. Greater male variability with respect to mathematics, where it exists, correlates with several measures of gender inequality.

Hyde, J. S., & Mertz, J. E. (2009). Gender, culture, and mathematics performance. Proceedings of the National Academy of Sciences, 106(22), 8801-8807.

Else-Quest, N.M., Hyde, J.S. & Linn, M.C. 2010. Cross-national patterns of gender differences in mathematics: A meta-analysis. Psychological Bulletin, 136(1), 103-127.

http://spectrum.ieee.org/at-work/education/math-quiz-why-do-men-predominate 
http://www.physorg.com/news181915640.html

Iron deficiency may affect maths achievement in children and teens

A U.S. national study of 5,398 children aged 6 to 16 found iron deficiency in 3% of the children overall, and 8.7% of girls aged 12 to 16 (7% without anemia). Average math scores for iron-deficient children with or without anemia were about six points lower than those with normal iron levels. Among adolescent girls, the difference in scores was more than eight points. Previous research has linked iron-deficiency anemia with lower developmental test scores in young children, but there is less information on older children and on iron deficiency without anemia. It is suggested that this finding may help explain why the female superiority in maths at younger ages reverses itself in adolescence.

Halterman, J.S., Kaczorowski, J.M., Aligne, C.A., Auinger, P. & Szilagyi, P.G. 2001. Iron Deficiency and Cognitive Achievement Among School-Aged Children and Adolescents in the United States. Pediatrics, 107 (6), 1381-1386.

Math Anxiety

Positive stereotypes can offset negative stereotype effect

A number of studies have now shown that negative stereotypes can impair cognitive performance, mainly through adding to working memory load. A new study has now shown that this effect can be mitigated by the activation of a positive stereotype. The research takes advantage of the fact that we all belong to several social groups. In this case, the relevant groups were ‘female’ and ‘college student’. As usual, when (subtly) reminded of negative stereotypes for women and math, women performed worse. The interesting thing was that this didn’t happen if women were also made aware that college students performed better at math than non-college students. Moreover, this was reflected in working memory capacity. It seems that, when both a positive and a negative stereotype are offered, people will tend to choose the positive stereotype, and the effects of this will cancel out the negative stereotype. It’s also worth noting how easily these stereotypes are activated: effects could be manipulated simply by subtly changing demographic questions asked before the test (and it is not uncommon that test-takers are first required to answer some demographic questions).

Rydell, R.J., McConnell, A.R. & Beilock, S.L. 2009. Multiple social identities and stereotype threat: Imbalance, accessibility, and working memory. Journal of Personality and Social Psychology, 96(5), 949-966.

http://www.eurekalert.org/pub_releases/2009-05/iu-pob050109.php

Stereotype-induced math anxiety robs women's working memory

Another study finds evidence that being told men are better at mathematics undermines women's math performance, and extends it by demonstrating that the anxiety induced by the stereotype mainly reduced the verbal part of working memory, and that this carried over to subsequent (non-math-related) tasks. The accuracy of women exposed to the stereotype was reduced from nearly 90% in a pretest to about 80% after being told men do better in mathematics.

Beilock, S.L., Rydell, R.J. & McConnell, A.R. 2007. Stereotype threat and working memory: Mechanisms, alleviation, and spillover. Journal of Experimental Psychology: General, 136(2), 256-276.

http://www.physorg.com/news99239898.html
http://www.eurekalert.org/pub_releases/2007-05/uoc-sma052107.php

Implicit stereotypes and gender identification may affect female math performance

Relatedly, another study has come out showing that women enrolled in an introductory calculus course who possessed strong implicit gender stereotypes, (for example, automatically associating "male" more than "female" with math ability and math professions) and were likely to identify themselves as feminine, performed worse relative to their female counterparts who did not possess such stereotypes and who were less likely to identify with traditionally female characteristics. Strikingly, a majority of the women participating in the study explicitly expressed disagreement with the idea that men have superior math ability, suggesting that even when consciously disavowing stereotypes, female math students are still susceptible to negative perceptions of their ability.

Kiefer, A.K., & Sekaquaptewa, D. 2007. Implicit stereotypes, gender identification, and math performance: a prospective study of female math students. Psychological Science, 18(1), 13-18.

http://www.eurekalert.org/pub_releases/2007-01/afps-isa012407.php

Women's math performance affected by theories on sex differences

In a salutary reminder to all researchers into gender and race differences, researchers found that women who received a genetic explanation for female underachievement in math or were reminded of the stereotype about female math underachievement, performed more poorly on math tests than those who received an experiential explanation (such as math teachers treating boys preferentially during the first years of math education) or were led to believe there are no sex differences in math.

Dar-Nimrod, I. & Heine, S.J. 2006. Exposure to Scientific Theories Affects Women's Math Performance. Science, 314 (5798), 435.

http://www.eurekalert.org/pub_releases/2006-10/uobc-wmp101306.php

Anxiety over maths blocks learning

The so-called "maths block" is notorious - why do we have such a term? Do we talk about a "geography block", or a "physics block"? But we do talk of a reading block. Perhaps the reason for both is the same.
The amount of information you can work with at one time has clear limits, defined by your working memory capacity. When we are anxious, part of our working memory is taken up with our awareness of these fears and worries, leaving less capacity available for processing (which is why students who are very anxious during exams usually perform well below their capabilities). Processes such as reading and working with numbers are very sensitive to working memory capacity because they place such demands on it.
A recently reported study by Mark H. Ashcraft and Elizabeth P. Kirk, both psychologists at Cleveland (Ohio) State University, provides the first solid evidence that, indeed, math-anxious people have working memory problems as they do maths.

Ashcraft, M. H., & Kirk, E. P. (2001). The relationships among working memory, math anxiety, and performance. Journal of Experimental Psychology: General, 130(2), 224–237. doi:10.1037/0096-3445.130.2.224

Neural substrate of mathematics

Where math takes place normally and in children with fetal alcohol spectrum disorder

An imaging study involving 21 children with fetal alcohol spectrum disorder confirms the importance of the left parietal area for mathematical tasks. Children with FASD are particularly impaired in mathematical ability. Brain activity patterns also revealed that the involvement of regions in the left cerebellum and the brainstem in math processing may be specific to children with FASD.

Lebel, C., Rasmussen, C., Wyper, K., Andrew, G., & Beaulieu, C. (2009). Brain Microstructure Is Related to Math Ability in Children With Fetal Alcohol Spectrum Disorder. Alcoholism: Clinical and Experimental Research, 9999(9999). doi: 10.1111/j.1530-0277.2009.01097.x.

http://www.eurekalert.org/pub_releases/2009-11/ace-ema111209.php

Are language and math processed separately by the brain?

Challenging the view that mathematics and language use common cognitive resources, a recent study provides support for the view that the functions of math and language are separate in the human brain. The study involved three men with severe agrammatic aphasia, which means they're unable to understand or form sentences due to brain damage. They didn't understand a reversible sentence - for example, the difference between 'John kissed Kate' and 'Kate kissed John', but they were able to understand that 5 - 2 is different from 2 – 5 (but not when it was expressed in words: two minus five). The researcher takes the results as a demonstration that we can have cognition without language, however, because the men were all normal until they sustained brain damage, it doesn’t answer the question of whether sophisticated cognition could arise without language.

Varley, R.A., Klessinger, N.J.C., Romanowski, C.A.J. & Siegal, M. 2005. Agrammatic but numerate. Proceedings of the National Academy of Sciences, 102 (9), 3519-3524.

http://education.guardian.co.uk/egweekly/story/0,,1427167,00.html
http://news.bbc.co.uk/1/hi/sci/tech/4265763.stm
http://www.nature.com/news/2005/050214/full/050214-3.html

tags study: 

Self-regulation

Older news items (pre-2010) brought over from the old website

Pointers for better learning

One of the crucial aspects to learning efficiently is being able to accurately assess your own learning process. Research has shown that in general people are not very accurate at judging how well they have learned complex materials. A review of recent research into how to improve judgment accuracy has concluded that rereading or summarizing text can help, as well as techniques that focus people’s attention on just the most important details of a text, such as trying to recall the key ideas from memory.

Dunlosky, J. & Lipko, A.R. 2007. Metacomprehension: A Brief History and How to Improve Its Accuracy. Current Directions in Psychological Science, 16 (4), 228–232.

http://www.eurekalert.org/pub_releases/2007-08/afps-rpt082307.php
http://www.sciencedaily.com/releases/2007/08/070823142827.htm

tags study: 

Environment

Older news items (pre-2010) brought over from the old website

Aircraft noise may affect children's reading and memory

A large study involving 2844 children aged 9-10 has found exposure to aircraft noise impaired reading comprehension. The children were selected from primary schools located near three major airports — Schiphol in the Netherlands, Barajas in Spain, and Heathrow in the UK. Reading age in children exposed to high levels of aircraft noise was delayed by up to 2 months in the UK and by up to 1 month in the Netherlands for each 5 decibel change in noise exposure. On the other hand, road traffic noise did not have an effect on reading and indeed was unexpectedly found to improve recall memory. An earlier German study found children attending schools near the old Munich airport improved their reading scores and cognitive memory performance when the airport shut down, while children going to school near the new airport experienced a decrease in testing scores.

Stansfield, S.A., Berglund, B., Clark, C., Lopez-Barrio, I., Fischer, P., Öhrstrom, E., Haines, M.M., Head, J., Hygge, S., van Kamp, I. & Berry, B.F. 2005. Aircraft and road traffic noise and children's cognition and health: a cross-national study. The Lancet, 365, 1942-1949.

http://www.eurekalert.org/pub_releases/2005-06/l-eta060105.php

TV & Video Games

There is no doubt that video games and television have an impact on cognition. Whether this impact is positive or negative depends on the content and the individual. Strategic video games have been found to improve cognitive skills in older adults (so has searching the internet); video games have been found to improve mental rotation skills, visual and spatial memory, and multitasking skills. Playing the game Dance Revolution was found in one study to affect emotional arousal, and through that, creativity. More negatively, violent video games also can affect emotional arousal and attention.

But amount is also important, particularly for television, which is a far more passive activity. Active mental stimulation supports cognition, especially in older adults, and too many hours spent watching TV means less time available to engage in activities which truly stimulate your mind. You don't have to do crosswords -- even talking to other people is a far more stimulating activity than watching television.

Older news items (pre-2010) brought over from the old website

Video games may help visuospatial processing and multitasking

Another study has come out showing that expert video gamers have improved mental rotation skills, visual and spatial memory, and multitasking skills. The researchers conclude that training with video games may serve to reduce gender differences in visual and spatial processing, and some of the cognitive declines that come with aging.

[366] Dye, M. W. G., Green S. C., & Bavelier D.
(2009).  Increasing Speed of Processing With Action Video Games.
Current Directions in Psychological Science. 18(6), 321 - 326.

http://www.eurekalert.org/pub_releases/2009-12/afps-rsa121709.php

Strategic video game improves critical cognitive skills in older adults

In the first study into the effects of playing video games for adults in their 60s and 70s, it’s been found that playing a strategic video game that rewards nation-building and territorial expansion can have pronounced effects on cognitive skills not directly related to the skills learned in the video game. The finding is also exciting as a rare demonstration of a training program that improves more than simply the task being practiced. The game "Rise of Nations" was selected because of its emphasis on resource management and planning. The researchers hoped it would benefit executive function, which is one of the cognitive functions particularly impacted by age and includes things like scheduling, planning, working memory, multitasking and dealing with ambiguity. Half of the 40 older adults in the study received 23.5 hours of training in the game. As a group, the gamers became significantly better and faster at switching between tasks as compared to the comparison group. Their working memory and their reasoning ability was also significantly improved. To a lesser extent, their short-term memory of visual cues and their ability to identify rotated objects was also improved. Training had no effect on ability to recall a list of words in order, enumeration ability or ability to inhibit certain responses. The amount of improvement was linked to performance on the game.

[813] Basak, C., Boot W. R., Voss M. W., & Kramer A. F.
(2008).  Can training in a real-time strategy video game attenuate cognitive decline in older adults?.
Psychology and Aging. 23(4), 765 - 777.

http://www.eurekalert.org/pub_releases/2008-12/uoia-svg120808.php

Frequent TV viewing during adolescence linked with risk of attention and learning difficulties

A long-running study of 678 families in upstate New York, surveyed children at 14, 16 and 22 years old (averages), and again when the children in the study had reached an average age of 33. At age 14, 225 (33.2%) of the teens reported that they watched three or more hours of television per day. Those who watched 1 or more hours of television per day at mean age 14 years were at higher risk of poor homework completion, negative attitudes toward school, poor grades, and long-term academic failure. Those who watched 3 or more hours of television per day were most likely to experience these outcomes, and moreover were at higher risk of subsequent attention problems and were the least likely to receive postsecondary education. Analysis of the data also indicated that television watching contributes to learning difficulties and not vice versa.

Johnson, J.G., Cohen, P., Kasen, S. & Brook, J.S. 2007. Extensive Television Viewing and the Development of Attention and Learning Difficulties During Adolescence. Archives of Pediatrics & Adolescent Medicine, 161 (5), 480-486.

http://www.eurekalert.org/pub_releases/2007-05/jaaj-ftv050307.php

TV has negative impact on very young children's learning abilities

Analysis of data involving some 1800 children from The National Longitudinal Survey of Youth 1979 (NLSY-Child) compared scores in mathematics, reading recognition and reading comprehension with the level of television watching before age three and from ages three to five. The analysis revealed a consistent pattern of negative associations between television viewing before age three years and adverse cognitive outcomes at ages six and seven years. Television viewing at ages three to five years, on the other hand, had a more beneficial effect, for reading recognition and short-term memory, although not mathematics or reading comprehension.

Another study in the same issue reported on a New Zealand study that compared television viewing in some 1000 people born in 1972-73 with their educational achievements at 26 years of age. The study found mean time spent watching television during childhood and adolescence was significantly associated with leaving school without qualifications and negatively associated with attaining a university degree. Television viewing during childhood (ages 5-11 years) and adolescence (ages 13 and 15 years) had adverse associations with later educational achievement. However, adolescent viewing was a stronger predictor of leaving school without qualifications, whereas childhood viewing was a stronger predictor of nonattainment of a university degree.

Zimmerman, F.J. & Christakis, D.A. 2005. Children’s Television Viewing and Cognitive Outcomes: A Longitudinal Analysis of National Data. Archives of Pediatrics & Adolescent Medicine, 159, 619-625.

Hancox, R.J., Milne, B.J. & Poulton, R. 2005. Association of Television Viewing During Childhood With Poor Educational Achievement. Archives of Pediatrics & Adolescent Medicine, 159, 614-618.

http://www.eurekalert.org/pub_releases/2005-07/jaaj-thn062905.php

The reports below are taken from my previous blog, and lack references

Effect on the brain

Emotional effect of video games can help creativity

As part of the search for ways to use video games educationally, a study of around 100 students has found that those who scored highly on a creativity test after playing the game Dance Dance Revolution fell into two groups: those who had a high degree of emotional arousal (measured by skin conductance) after playing and a positive mood, and (this is the weird part), those in the completely opposite camp — low arousal and negative mood.
The explanation for these somewhat paradoxical findings rests on there being two aspects to creativity — diffused attention (presumably where the happy people score), and a certain analytical ability (which is where the sad people are presumed to score).
It still seems weird, but the take-home point I guess is that being angry (high arousal, negative mood) is not conducive to creativity, and neither is medium arousal. On the other hand, I’m wondering about individual differences. I think some people probably are creative when angry, and I’d like to know about personality characteristics that might have distinguished the students who were creative when happy from those who were creative when sad. Still, interesting study.

Watching violence begets violence?

There’s lots of argument about whether watching violence on TV and in movies makes people more violent. Some studies have found a correlation, but correlational studies can always be attacked.  But now a brain imaging study has found that watching violent movie clips (but not ones with scenes of horror or physical activity) can cause the parts of your brain that suppress behaviors like inappropriate or unwarranted aggression (such as the right lateral orbitofrontal cortex, and the amygdala) to become less active. Less activation in this network is characteristic of people reporting an above average tendency to behave aggressively.

http://www.physorg.com/news116155534.html

Violent video games leave teenagers emotionally aroused

An imaging study of 44 adolescents playing either a violent or a nonviolent video game for 30 minutes has found that the group that played the violent video game demonstrated less activation in the prefrontal portions of the brain, which are involved in inhibition, concentration and self-control, and more activation in the amygdala, which is involved in emotional arousal.

http://www.eurekalert.org/pub_releases/2006-11/rson-vvg112206.php

Violent games desensitize players to violence

In a study in which 257 college students played one of eight randomly assigned violent or non-violent video games for 20 minutes, followed by a 10-minute videotape of actual violent episodes taken from TV programs and movies, has found that the real violence produced significantly lower physiological arousal (measured by galvanic skin response and heart rate) in those who had played a violent video game. There was no difference in arousal between the two groups after playing the games, and before seeing the videotape, showing that the effect was to desensitize individuals to real-life violence.

http://www.sciencedaily.com/releases/2006/07/060727162108.htm

Effect on children

Most Middle-school Boys And Many Girls Play Violent Video Games

A survey of over 1200 American middle-school kids (12-14 years) has found that almost all of them, boys and girls both, play video games, and most of them regularly play violent ones. Even girls rated the notorious Grand Theft Auto as the second most popular series (it was the top pick for boys). Boys do play more than girls — a third of the boys played almost every day, compared to only 10% of girls. But on the bright side, the games aren’t as anti-social as commonly portrayed — the kids often play in groups, either in the same room or over the internet, and boys’ friendships often center around games (I have to concur with this — a lot of the bonding between my sons occurs through the playing together and endlessly conversing about, games). The study also found that many children were playing video games to manage their feelings (although it seems to me as an observer that games are great for creating intense frustration in susceptible people!).

http://www.sciencedaily.com/releases/2007/07/070703172538.htm

Effect Of Removing TV, Games Consoles And Computers On Young Children

The BBC filmed 23 7 and 8-year-old children in school, and in some cases at home, over a five-week period, which included two weeks when half of them had their TV sets, PCs and portable game consoles removed or disabled. Even after just two weeks, families found they began to interact more, even to `rediscover' their pleasure in each other's company. Some parents admitted the experiment had shown up how they had allowed themselves to rely too much on on-screen entertainment to keep children amused while they got on with their own business. They also found children tired from an active evening were more liable to go to bed early and wake up refreshed and alert the next day. Although there was no conclusive evidence that the temporary absence of TV and game consoles resulted in changed behaviour in school (it was after all only for 2 weeks), but many of the children showed more enthusiasm for doing homework.

I have to say, my family do a lot of talking, and sometimes go through bursts of card-playing, even though we have a TV, computers, and Playstation — but we only got the TV and Playstation a couple of years ago, when the boys were in their mid-teens (similarly, before that time, computer games were all of the ‘educational’ variety, and time limits imposed). I think the important thing is to keep strict control during the earlier years.

http://www.sciencedaily.com/releases/2007/06/070619172711.htm

Watching TV reduces pain, anxiety

Here’s an interesting, and for a mother somewhat worrying, study: 69 7-12 year-old children in hospital were asked to rate their pain when they were stuck with needle to take a blood sample. Those watching TV cartoons reported half the pain as those who were being soothed by their mother, and a third the pain of those who just sat in a hospital room with mothers who didn't try to soothe them. Does this point to the power of TV, or just the limitations of a mother? Other studies have found that the mothers and fathers attempts at comforting often backfire because it makes the children feel that "something must really be bad".

http://www.medscape.com/viewarticle/548718

 

Prematurity

Older news items (pre-2010) brought over from the old website

Intake of certain fatty acid appears to improve neurodevelopment for preterm girls, but not boys

A large randomized trial of infants born at less than 33 weeks' gestation from five Australian hospitals has found that girls who received a high supplementary daily dose of DHA (an omega-3 fatty acid) in either their breast milk or infant formula until their expected delivery date performed significantly better on a mental development test when they were 18 months old than girls who received a low dose. However, bafflingly, boys showed no effect.

Makrides, M. et al. 2009. Neurodevelopmental Outcomes of Preterm Infants Fed High-Dose Docosahexaenoic Acid: A Randomized Controlled Trial. JAMA, 301(2), 175-182.

http://www.eurekalert.org/pub_releases/2009-01/jaaj-ioc010809.php

Early cognitive tests of premature predict later development

A number of studies have shown that premature birth increases a child's risk of learning and other cognitive disabilities, including lower IQ, language delay, poorer school achievement and learning disabilities. A new study has now found that early cognitive deficits apparent at 7 months (such as poorer attention, slower processing speed and poorer recognition memory) fully account for lower cognitive scores of 2- and 3-year-olds. This suggests that cognitive difficulties can be identified early, with the hope of successful intervention.

Rose, S.A., Feldman, J.F., Jankowski, J.J. & Van Rossem, R. 2005. Pathways From Prematurity and Infant Abilities to Later Cognition. Child Development, 76 (6), 1172

http://www.eurekalert.org/pub_releases/2005-11/sfri-ort110805.php

Why premature brains improve over time

A new study explains why premature babies often develop better than expected. A mouse study has found that infants born prematurely and with hypoxia (inadequate oxygen to the blood) are able to recover some cells, volume and weight in the brain after oxygen supply is restored, by a process of neurogenesis.

Fagel, D.M., Ganat, Y., Silbereis, J., Ebbitt, T., Stewart, W., Zhang, H., Ment, L.R. & Vaccarino, F.M. 2005. Cortical neurogenesis enhanced by chronic perinatal hypoxia. Experimental Neurology, In Press.

http://www.eurekalert.org/pub_releases/2005-06/yu-gsh062705.php

Interestingly, another recent study, following up an earlier study when premature infants with respiratory distress syndrome were given inhaled nitric oxide (decreasing the risk of death or chronic lung disease), has found that the treatment also improve neurodevelopmental outcomes. 24% of those given nitric oxide had abnormal neurodevelopmental outcomes at two years of age compared to 46% in the placebo group.

Mestan, K.K.L., Marks, J.D., Hecox, K., Huo, D. & Schreiber, M.D. 2005. Neurodevelopmental Outcomes of Premature Infants Treated with Inhaled Nitric Oxide. NEJM, 353 (1), 23-32.

Effect of prematurity on brain worse for boys

A comparison of the brain volumes of 65 8-year-olds born prematurely to 31 children born full-term has found significantly smaller areas in the cerebral cortex, especially in parts responsible for reading, language, emotion and behavior. However, significant gender differences were found. Only the preterm boys showed significant reductions in white matter volume. Only the preterm girls showed a positive correlation between gray matter volume and cognitive outcome. The study suggests that the gender of the preterm child affects the way in which the developing brain is affected, and also suggests that boys are more negatively affected by prematurity. Previous studies have indicated more adverse cognitive outcomes for preterm boys than preterm girls. This latest study suggests that an approach to stimulate white matter growth in preterm boys would be promising.

Reiss, A.L., Kesler, S.R., Vohr, B., Duncan, C.C., Katz, K.H., Pajot, S., Schneider, K.C., Makuch, R.W., Ment, L.R. 2004. Sex differences in cerebral volumes of 8-year-olds born preterm. The Journal of Pediatrics, 145 (2), 242-9.

More evidence of long-lasting cognitive deficits in pre-term babies

298 children born during 1991-1992 with birth weights less than 1000g or born earlier than 28 weeks'gestation were compared with 262 randomly selected children with birthweights of more than 2499 g.The premature children scored significantly below the control group onIQ (an average drop of 9.4 points) and indices of verbalcomprehension, perceptual organization, freedomfrom distractibility, and processing speed. They also performed significantly worseon tests of reading, spelling,and arithmetic. Attentional difficulties, internalizing behavior problems, and immature adaptive skills were also more prevalent in the group.

Anderson, P., Doyle, L.W. & the Victorian Infant Collaborative Study Group. 2003. Neurobehavioral Outcomes of School-age Children Born Extremely Low Birth Weight or Very Preterm in the 1990s. JAMA, 289,3264-3272.

Low birth weight still impacting exam scores 16 years on

A study of 334 16-year-olds found that those who weighed 1,500 grams or less at birth, scored an average of 32.33 on their GCSEs (the researchers gave a numerical score to each GCSE grade, starting with eight for A*), compared to an average score of 36.78 for those with a normal birth weight. The difference was greatest for maths and statistics. There was no difference in results for geography and history, and the normal birth weight group achieved better results in general science and English. The participants were closely matched for school and several social variables.

Pharoah, P.O.D., Stevenson, C.J. & West, C.R. 2003. General Certificate of Secondary Education performance in very low birthweight infants. Archives of Disease in Childhood, 88, 295-298.

http://news.bbc.co.uk/1/hi/health/2880627.stm

Cognitive abilities increase with time in most premature children

Many studies have found that children born prematurely with very low birthweight have an increased risk of many neurological problems, including cognitive handicaps. New research shows that most of these children improve significantly on tests of cognitive function during early childhood and score within the normal range on tests of verbal comprehension and intelligence by age 8.

Ment, L.R., Vohr, B., Allan, W., Katz, K.H., Schneider, K.C., Westerveld, M., Duncan, C.C., Makuch, R.W. 2003. Change in Cognitive Function Over Time in Very Low-Birth-Weight Infants. Journal of the American Medical Association, 289 (6), 705-711.

http://www.eurekalert.org/pub_releases/2003-02/nion-cai020503.php

Pre-term infants' slowness in processing information still evident at 12 months

Pre-term infants tend to be slower at processing information than babies born full term. New research shows this deficit in processing speed (which can be shown, for example, in slower learning of new faces) is present at five months, and still evident at twelve months. Previous research has also indicated that a number of the medical risks suffered by pre-terms (such as respiratory distress syndrome)have an effect on processing speed. A deficit in processing speed has implications for measures of intelligence, language and academic achievement, such as reading, arithmetic and spelling.

Rose, S.A., Feldman, J.F. & Jankowski, J.J. 2002. Processing Speed in the 1st Year of Life: A Longitudinal Study of Preterm and Full-Term Infants. Developmental Psychology, 38 (6), 895–902.

http://www.eurekalert.org/pub_releases/2002-11/apa-pis110402.php

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.

Isaacs, E.B., Edmonds, C.J., Lucas, A. & Gadian, D.G. (2001). Calculation difficulties in children of very low birthweight: A neural correlate. Brain, 124 (9, 1701-1707.

http://news.bbc.co.uk/hi/english/sci/tech/newsid_1512000/1512664.stm

Fragile X

Older news items (pre-2010) brought over from the old website

New method of scoring IQ tests for fragile X children

IQ tests can tell us little about the learning abilities of children with intellectual disabilities, as parents of such children know only too well. So it’s exciting to learn that a new system of scoring IQ tests has been devised for children with fragile X syndrome. This new test reflects the variability evident among learning disabled children, and tells parents, teachers and doctors how a child with fragile x syndrome deviates from the normal population in every sub-test area. The researchers also found a significant correlation between the scores and the level of FMR1 protein in the blood (the protein expressed by the normal variant of the so-called fragile X gene), and between the IQ test scores and scores on the Vineland Adaptive Behavior Composite, which measures personal and social skills used in everyday living.

[886] Reiss, A. L., Hall S., Hessl D., Nguyen D. V., Green C., Chavez A., et al.
(2009).  A solution to limitations of cognitive testing in children with intellectual disabilities: the case of fragile X syndrome.
Journal of Neurodevelopmental Disorders. 1(1), 33 - 45.

http://www.physorg.com/news148642082.html

Acne drug may help those with Fragile X syndrome

A new mouse study has found that a readily available drug called minocycline, used widely to treat acne and skin infections, helps Fragile X syndrome. Human trials have already been approved. The study has revealed that dendritic spine development is impaired in mice with Fragile X, and that this drug reduces levels of the enzymes interfering with their healthy development. The mice showed healthier dendritic spines, reduced anxiety, and improved cognition.

[863] Bilousova, T. V., Dansie L., Ngo M., Aye J., Charles J. R., Ethell D. W., et al.
(2009).  Minocycline promotes dendritic spine maturation and improves behavioural performance in the fragile X mouse model.
Journal of Medical Genetics. 46(2), 94 - 102.

http://www.eurekalert.org/pub_releases/2008-10/uoc--urp100308.php

Fragile X retardation syndrome corrected in mice

In another study targeting the glutamate receptor mGluR5, researchers have fixed multiple defects in fragile X mice by reducing these receptors by 50%. They achieved this through genetic engineering, but drugs blocking mGluR5 receptors are now entering human clinical trials. Fragile X is the most common form of inherited mental retardation and a leading identified genetic cause of autism.

[1306] Dölen, Gül, Osterweil E., Rao S. B. S., Smith G. B., Auerbach B. D., Chattarji S., et al.
(2007).  Correction of Fragile X Syndrome in Mice.
Neuron. 56(6), 955 - 962.

http://www.eurekalert.org/pub_releases/2007-12/cp-fxr121407.php
http://www.eurekalert.org/pub_releases/2007-12/miot-mci121407.php

Mouse study points to new therapy for Fragile X sufferers

A mouse study has found evidence that fragile X mutation produces a highly selective impairment to long-term potentiation in hippocampal cells, and that adding brain-derived neurotrophic factor (BNDF) proteins to the hippocampus restored it.

[1064] Lauterborn, J. C., Rex C. S., Kramar E., Chen L. Y., Pandyarajan V., Lynch G., et al.
(2007).  Brain-Derived Neurotrophic Factor Rescues Synaptic Plasticity in a Mouse Model of Fragile X Syndrome.
J. Neurosci.. 27(40), 10685 - 10694.

http://www.eurekalert.org/pub_releases/2007-10/uoc--urr100507.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.

[647] Nakamoto, M., Nalavadi V., Epstein M. P., Narayanan U., Bassell G. J., & Warren S. T.
(2007).  Fragile X mental retardation protein deficiency leads to excessive mGluR5-dependent internalization of AMPA receptors.
Proceedings of the National Academy of Sciences. 104(39), 15537 - 15542.

http://www.eurekalert.org/pub_releases/2007-09/eu-sif091307.php

Fragile X syndrome -- A stimulating environment restores neuronal function in mice

Mice in which the gene that causes Fragile X syndrome —- the most common form of inherited mental retardation — in humans had been knocked out, showed reduced long-term potentiation in neurons due to abnormalities in the channels that regulate the flow of calcium into neurons. Excitingly, exposure to an enriched environment restored normal neuronal plasticity, suggesting that mechanisms for synaptic plasticity are in place, they just require stronger neuronal activity to be triggered.

[638] Meredith, R. M., Holmgren C. D., Weidum M., Burnashev N., & Mansvelder H. D.
(2007).  Increased Threshold for Spike-Timing-Dependent Plasticity Is Caused by Unreliable Calcium Signaling in Mice Lacking Fragile X Gene Fmr1.
Neuron. 54(4), 627 - 638.

http://www.physorg.com/news99144459.html
http://www.eurekalert.org/pub_releases/2007-05/cp-fxs051807.php

tags problems: 

Dyslexia Therapy

Older news items (pre-2010) brought over from the old website

Remedial reading program improves brain wiring in children

An imaging study involving 72 children aged 8 to 10 has provided the first evidence that intensive instruction to improve reading skills in young children causes the brain to physically rewire itself. The study found that the ability of white matter tracts to transmit signals efficiently improved substantially after the children received six months (100 hours) of remedial training. Moreover, those who showed the most white matter change also showed the most improvement in reading ability. Previous research has found that both children and adults with reading difficulty display areas of compromised white matter.

[963] Keller, T. A., & Just M A.
(2009).  Altering Cortical Connectivity: Remediation-Induced Changes in the White Matter of Poor Readers.
Neuron. 64(5), 624 - 631.

http://www.physorg.com/news179584529.html
http://www.npr.org/templates/story/story.php?storyId=121253104

Pre-school exercises can prevent dyslexia

A study comparing 107 children with either parent dyslexic and a control group of children without a hereditary predisposition to dyslexia has found that half the children with a dyslexic parent found learning to read more challenging than children in the control group. The predictors of reading and writing difficulties were evident primarily in two contexts: as a delayed ability to perceive and mentally process the subtleties of speech sound, and as a sluggishness in naming familiar, visually presented objects. The difficulties children experience when learning to read can be significantly reduced through training, and the CoE in Learning and Motivation Research has developed computer game-like learning environments to aid preventive training, and made them available on the internet free of charge. It’s recommended that the child start these exercises before school, if possible.  The exercises and tools are all available at www.lukimat.fi.

The results were presented at the Academy of Finland's science breakfast on 21 August.

http://www.eurekalert.org/pub_releases/2008-08/aof-pae082708.php

Remedial instruction can close gap between good, poor readers

A brain imaging study of poor readers has found that 100 hours of remedial instruction not only improved the skills of struggling readers, but also changed the way their brains activated when they comprehended written sentences. 25 fifth-graders who were poor readers worked in groups of three for an hour a day with a reading "personal trainer," a teacher specialized in administering a remedial reading program. The training included both word decoding exercises in which students were asked to recognize the word in its written form and tasks in using reading comprehension strategies. Brain scans while the children were reading revealed that the parietotemporal region — responsible for decoding the sounds of written language and assembling them into words and phrases that make up a sentence — was significantly less activated among the poor readers than in the control group. The increases in activation seen as a result of training were still evident, and even greater, a year later.
Although dyslexia is generally thought of as caused by difficulties in the visual perception of letters, leading to confusions between letters like "p" and "d", such difficulties occur in only about 10% of the cases. Most commonly, the problem lies in relating the visual form of a letter to its sound.

[702] Meyler, A., Keller T. A., Cherkassky V. L., Gabrieli J. D. E., & Just M A.
(2008).  Modifying the brain activation of poor readers during sentence comprehension with extended remedial instruction: A longitudinal study of neuroplasticity.
Neuropsychologia. 46(10), 2580 - 2592.

http://www.eurekalert.org/pub_releases/2008-06/cmu-cmb061108.php

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.

[844] Richards, T. L., & Berninger V. W.
(2008).  Abnormal fMRI Connectivity in Children with Dyslexia During a Phoneme Task: Before But Not After Treatment.
Journal of neurolinguistics. 21(4), 294 - 304.

http://www.eurekalert.org/pub_releases/2007-09/uow-hrt090407.php
http://www.sciencedirect.com/science/journal/09116044

New insight into brain and speech promises help for learning disabilities

Following a new understanding of the nature of certain language dysfunctions, researchers have devised a new non-invasive diagnostic tool called BioMAP that can quickly identify children with a subset of learning disabilities that results from a dysfunction in the way the brainstem encodes certain basic sounds of speech. Such children accounted for nearly a third of the language-disordered children the researchers studied. BioMAP measures whether a child's nervous system can accurately translate a sound wave into a brain wave. If it cannot, the affected individual demonstrates problems in discriminating speech sounds that interfere with normal learning. Once identified, children with these problems will be able to improve their speech discrimination skills through auditory training.

[789] Kraus, N., & Nicol T.
(2005).  Brainstem origins for cortical 'what' and 'where' pathways in the auditory system.
Trends in Neurosciences. 28(4), 176 - 181.

http://www.eurekalert.org/pub_releases/2005-04/nu-nii040405.php

Promise for helping adults with dyslexia

Recent studies have demonstrated that children with dyslexia can benefit from programs aimed at “retraining” the brain. Now a new study shows that adults with dyslexia can also benefit from tutoring in processing words, and their brains show changes that indicate neural modifications due to the training.

[454] Eden, G. F., Jones K. M., Cappell K., Gareau L., Wood F. B., Zeffiro T. A., et al.
(2004).  Neural Changes following Remediation in Adult Developmental Dyslexia.
Neuron. 44(3), 411 - 422.

http://www.eurekalert.org/pub_releases/2004-10/cp-pfh102204.php

Immature motion pathways in the brain associated with poor reading skills

An interactive computer game called MovingToRead (MTR) has significantly improved reading skills in poor second-grade readers within three months by practicing left-right movement discrimination for 5 to 10 minutes once or twice a week. It has been suggested that immature motion pathways — the circuit of neurons that helps readers determine the location of letters of a word and words on a page — may be related to reading problems in children. The therapy appears to be most effective with second-graders (age 7).

http://www.eurekalert.org/pub_releases/2003-11/sfn-ssb111103.php

Short-term dyslexia treatment strengthens key brain regions

A group of dyslexic children and a group of good readers of the same age underwent functional magnetic resonance imaging (fMRI) to map their brain activation patterns during two types of reading tests. Both groups of children were found to use the same specific parts of their brains to perform the reading tasks, however, the activation of these regions was much weaker in the dyslexic children. The children with dyslexia then received a three-week training program based on principles outlined by the National Reading Panel (http://www.nationalreadingpanel.org). After this program the levels of brain activation were found to be essentially the same in the two groups.

[261] Aylward, E. H., Richards T. L., Berninger V. W., Nagy W. E., Field K. M., Grimme A. C., et al.
(2003).  Instructional treatment associated with changes in brain activation in children with dyslexia.
Neurology. 61(2), 212 - 219.

http://www.eurekalert.org/pub_releases/2003-07/aaon-sdt071503.php
More background on dyslexia including initial steps toward identifying it in a child, how it may be treated, and additional resources can be found in Neurology's "Patient Page" at http://www.neurology.org.

tags problems: 

Spacing Effect

See also

Practice

Testing

Older news items (pre-2010) brought over from the old website

The smart way to study

A large internet study has clarified the optimal timing for spacing out your learning. The very systematic study found much larger benefits to spacing your review of material than has been seen in earlier research when shorter intervals have been used. Given a fixed amount of study time, the optimal gap improved recall by 64% and recognition by 26%. Basically, the study found that if you want to remember just for a week, the optimal gap was one day; for remembering for a month, it was 11 days; for 2 months (70 days) it was 3 weeks, and similarly for remembering for a year. Extrapolating, it seems likely that if you’re wanting to remember information for several years, you should review it over several months. (You can read more about this study in my article on the most effective way of spacing your learning).

[872] Cepeda, N. J., Vul E., Rohrer D., Wixted J. T., & Pashler H.
(2008).  Spacing effects in learning: a temporal ridgeline of optimal retention.
Psychological Science: A Journal of the American Psychological Society / APS. 19(11), 1095 - 1102.

http://www.eurekalert.org/pub_releases/2008-11/uoc--tsw111808.php

Cramming doesn't work in the long term

Thinking back on how much you remember from your schooldays, it’s apparent to most of us that despite all the time spent in school, we’ve forgotten most of what we learned. A new study points to what we were doing wrong. The study looked at overlearning, which is the term for continuing to study after you’ve apparently learned it. Students went through a list of new words either five times (getting a perfect score no more than once) or ten times (getting it perfect at least three times). A week later, students who did the extra drilling performed better when tested, but four weeks later there was no difference. The results suggest that overlearning in a single session is wasted effort. However, when the material was studied in two separate sessions, and the break between sessions was at least a month, students did much better. Although the experiments involved rote learning, the researchers have also found similar effects with more abstract learning, like math.

[878] Rohrer, D., & Pashler H.
(2007).  Increasing Retention Without Increasing Study Time.
Current Directions in Psychological Science. 16(4), 183 - 186.

http://www.eurekalert.org/pub_releases/2007-08/afps-bts082907.php

Practicing skills in concentrated blocks not the most efficient way

While practicing several different skills in separate, concentrated blocks leads to better performance during practice, it appears that this approach is not the best method of learning for long-term retention. The temporary improvement in performance that results from blocked practice hinders learning because it allows people to overestimate how well they have learned a skill. For long-term retention, it appears that contextual-interference practice (practicing skills that are mixed with other tasks) results in better learning. This may be because such practice requires people to repeatedly retrieve the motor program corresponding to each task (repeated retrieval is a major factor in making stored memories easier to access). Such practice also requires the person to differentiate the skills in terms of their similarities and differences, which may be assumed to result in a better mental conceptualization of those skills. The fact that blocked practice leads to better short-term performance but poorer long-term learning "has great potential to fool teachers, trainers and instructors as well as students and trainees themselves."

[1167] Simon, D. A., & Bjork R. A.
(2001).  Metacognition in Motor Learning.
Journal of Experimental Psychology: Learning, Memory, and Cognition. 27(4), 907 - 912.

http://www.apa.org/releases/retention.html

tags strategies: 

Plastics

Older news items (pre-2010) brought over from the old website

Pollutants affect babies' brains

It appears that exposure to polychlorinated biphenyls (PCBs) in a mother's blood and breast milk can hinder the development of a baby's brain before and after birth. Although PCBs are now banned, these chemicals were once widely used in industry as coolants and lubricants and are still being leaked into the environment from old electrical equipment.

[591] Walkowiak, J., Wiener J. A., Fastabend A., Heinzow B., Krämer U., Schmidt E., et al.
(2001).  Environmental exposure to polychlorinated biphenyls and quality of the home environment: effects on psychodevelopment in early childhood.
Lancet. 358(9293), 1602 - 1607.

http://news.bbc.co.uk/hi/english/health/newsid_1644000/1644446.stm

PCB-laden fish may affect adult verbal memory

The dangers of PCBs (once widely used as electrical insulators and lubricants and in paints and varnishes) have long been known, and assumed to apply chiefly to children and developing fetuses. A long-term study of those who eat the PCB-laden fish from Lake Michigan suggests for the first time that high levels of PCB may cause problems learning and remembering new verbal information in adults. In particular, those with high blood PCB levels had difficulties recalling a story told just 30 minutes earlier, and were less likely than their less-exposed peers to cluster words given orally into categories based on their meaning to boost recall.

Schantz, S.L., Gasior, D.M., Polverejan, E., McCaffrey, R.J., Sweeney, A.M., Humphrey, H.E.B. & Gardiner, J.C. 2001. Impairments of Memory and Learning in Older Adults Exposed to Polychlorinated Biphenyls via Consumption of Great Lakes Fish. Environmental Health Perspectives, 109 (6), 605.

http://www.eurekalert.org/pub_releases/2001-06/UoIa-Hcot-0406101.php
http://ehpnet1.niehs.nih.gov/docs/2001/109-6/toc.html

How chronic exposure to solvents can impair the brain

Chronic occupational exposure to organic solvents, found in materials such as paints, printing and dry cleaning agents, has been linked to long-term cognitive impairment, but chronic solvent-induced encephalopathy (CSE) is still a controversial diagnosis. An imaging study of 10 CSE patients who had been exposed to solvents and had mild to severe cognitive impairment, 10 participants who had been exposed to solvents but had no CSE symptoms, and 11 participants who were not exposed to solvents and had no symptoms, has now found impairment in the frontal-striatal-thalamic (FST) circuitry of CSE patients. The disturbances are predictive of the clinical findings — impaired psychomotor speed and attention — and were also linked to exposure severity.

[989] van Dijk, F. J. H., Schene A. H., Heeten G D. J., Visser I., Lavini C., Booij J., et al.
(2008).  Cerebral impairment in chronic solvent-induced encephalopathy.
Annals of Neurology. 63(5), 572 - 580.

http://www.eurekalert.org/pub_releases/2008-04/w-dib041508.php

Chemical in clear plastics can impair learning

A rat study has found that low doses of the environmental contaminant bisphenol–A (BPA), widely used to make many plastics found in food storage containers (including feeding bottles for infants), inhibit estrogen–induction of synaptic connections in the hippocampus, suggesting implications for children's learning ability. Also, when the ability to make estrogen is impaired, as in old age, exposure to BPA could adversely affect hippocampal function and contribute to age–related neurodegenerative diseases such as Alzheimer's disease, in which hippocampal function is impaired. The doses were below the current U.S. Environmental Protection Agency reference daily limit for human exposure.

[740] MacLusky, N. J., Hajszan T., & Leranth C.
(2005).  The Environmental Estrogen Bisphenol A Inhibits Estradiol-Induced Hippocampal Synaptogenesis.
Environmental Health Perspectives. 113(6), 675 - 679.

http://www.eurekalert.org/pub_releases/2005-04/yu-cpi041205.php

 

tags lifestyle: 

Iron

A number of studies have found that iron deficiency in children and adolescents is associated with lower scores of cognitive tests. Moreover, there is some evidence that iron deficiency during infancy has persistent effects on cognition that are still evident in adolescence. This may be exacerbated for those with poor family conditions.

While iron deficiency was once presumed to exert most of its deleterious effects only if it reached the level of anemia, it has more recently become recognized that many organs show negative changes in functioning before there is any drop in iron hemoglobin concentration. A large U.S. national study found iron deficiency in 3% of children (6-16), and 8.7% of girls aged 12 to 16.

There has been less research done on the effects of iron deficiency on cognition in adults, but there are indications that iron deficiency is associated with poorer attention and working memory in both young and older women.

Older news items (pre-2010) brought over from the old website

Iron supplements might harm infants who have enough

U.S. infant formulas typically come fortified with 12 mg/L of iron to prevent iron-deficiency anemia, although Europe generally uses a lower amount. A study of 494 Chilean children has now showed that those who received iron fortified formula in infancy at the 12 mg level used in the U.S. lagged behind those who received low-iron formula in cognitive and visual-motor development by age 10 years. While most children who received the higher level formula did not show lower scores, the 5% with the highest hemoglobin levels at 6 months showed the poorest outcome. Adversely affected children scored 11 points lower in IQ and 12 points lower in visual-motor integration. This suggests that those who are not deficient in iron are adversely affected by giving them too much. It seems likely that more than 5% of U.S. infants will have high hemoglobin levels. More research is needed to confirm this finding.

Castillo, M. & Smith, J.B. 2008. Poorer developmental outcome at 10 years with 12 mg/L iron-fortified formula in infancy. Paper presented May 5 at the Pediatric Academic Societies annual meeting in Honolulu.

http://www.eurekalert.org/pub_releases/2008-05/uom-ism043008.php

Iron-deficient infants have lower cognitive scores at 19, especially in lower socioeconomic levels

Another study has come out finding that teenagers who were iron-deficient as infants continue to lag behind their peers in cognitive test scores, with a wider gap for children at lower socioeconomic levels. The study of 185 children from an urban area in Costa Rica, found that among children from middle-class families, initial scores on cognitive tests were eight points apart, 101.2 for those with iron deficiency and 109.3 for those with sufficient iron levels, and this gap remained at eight or nine points through 19 years. However, for those in lower socio-economic classes, initial scores that were ten points apart (93.1 for iron-deficient infants and 102.8 for those with normal iron levels) had widened by 19 years to 25 points (70.4 vs. 95.3). The finding points to the snowball effect of early failure.

[1145] Lozoff, B., Jimenez E., & Smith J. B.
(2006).  Double Burden of Iron Deficiency in Infancy and Low Socioeconomic Status: A Longitudinal Analysis of Cognitive Test Scores to Age 19 Years.
Arch Pediatr Adolesc Med. 160(11), 1108 - 1113.

http://www.eurekalert.org/pub_releases/2006-11/jaaj-idi110206.php

Impact of iron deficiency in infancy continues into adolescence

A new study has found that teens who suffered iron deficiency as infants are likely to score lower on cognitive and motor tests, even if that iron deficiency was identified and treated in infancy. The study followed 191 children. Those who were diagnosed with severe, chronic iron deficiency when they were 12-23 months old and were treated with iron supplements, lagged behind their peers in both motor and mental measures. The difference, moreover, actually increased over time. The iron-deficient infants scored about six points lower on cognitive tests at age 1-2 years, and 11 points lower at age 15-18 years. The gap was even more pronounced for children of families with low socioeconomic status, lower stimulation in the home or mothers lower in IQ. For children with good iron status, family conditions did not seem to affect their cognitive test scores. The researcher stressed that the children were not generally malnourished. Moreover, it must be emphasized that these children received treatment for their iron deficiency, yet still showed continuing ill effects, pointing to the need to prevent the deficiency occurring in the first place.

Lozoff, B. 2004. Longitudinal Analysis of Cognitive and Motor Effects of Iron Deficiency in Infancy. Presented at the Pediatric Academic Societies' annual meeting in San Francisco May 3.

http://www.eurekalert.org/pub_releases/2004-05/uom-iis050404.htm

American Academy of Pediatrics information on iron intake for infants: http://aappolicy.aappublications.org/cgi/content/full/pediatrics;104/1/119

Even moderate iron deficiency affects cognitive performance

A new study involving 149 young women (aged 18 to 35, average age 21), has found that iron supplementation significantly improved attention, short-term and long-term memory, and performance on cognitive tasks in those who were deficient in iron, even if not classified as anemic. On the baseline test, women who were iron deficient but not anemic completed the tasks in the same amount of time as iron sufficient women of the same age, but they performed significantly worse. Women who were anemic both performed significantly worse and took longer, with length of time increasing with degree of anemia. However, 16 weeks of iron supplementation markedly improved both scores and time to complete the task.
While iron deficiency was once presumed to exert most of its deleterious effects only if it had reached the level of anemia, it has more recently become recognized that many organs show negative changes in functioning before there is any drop in iron hemoglobin concentration. Iron deficiency is thought to occur in 9 – 11% of women of reproductive age and 25% of pregnant women. In non-industrialized countries, the prevalence of anemia is over 40% in non-pregnant women and over 50% for pregnant women and children aged five to 14.

Murray-Kolb, L., Beard, J. & Whitfield, K. 2004. presented at Experimental Biology 2004, in the American Society of Nutritional Sciences' scientific program.

http://www.eurekalert.org/pub_releases/2004-04/foas-mid040404.php

U.N. prescribes nutrient-fortified foods

A new U.N. survey says the brainpower of many developing countries has diminished because of a shortage of the right vitamins. To fight the problem, the United Nations is prescribing artificially fortified foods: soy sauce laced with zinc, "super salt" spiked with iron, cooking oil fortified with vitamin A. The report claimed a lack of iron lowered children's IQs by an average five to seven points, while a deficiency in iodine cuts it 13 more points. The report was produced by the Micronutrient Initiative and the United Nations Children's Fund.
http://www.micronutrient.org/

Iron deficiency may affect maths achievement in children and teens

A U.S. national study of 5,398 children aged 6 to 16 found iron deficiency in 3% of the children overall, and 8.7% of girls aged 12 to 16 (7% without anemia). Average math scores for iron-deficient children with or without anemia were about six points lower than those with normal iron levels. Among adolescent girls, the difference in scores was more than eight points. Previous research has linked iron-deficiency anemia with lower developmental test scores in young children, but there is less information on older children and on iron deficiency without anemia. It is suggested that this finding may help explain why the female superiority in maths at younger ages reverses itself in adolescence.

Halterman, J.S., Kaczorowski, J.M., Aligne, C.A., Auinger, P. & Szilagyi, P.G. 2001. Iron Deficiency and Cognitive Achievement Among School-Aged Children and Adolescents in the United States. Pediatrics, 107 (6), 1381-1386.

http://www.pediatrics.org/cgi/content/abstract/107/6/1381

Anemia linked to impaired thinking in older adults

For older adults, anemia has long been linked to fatigue, muscle weakness and other physical ailments. But a new study suggests it may also be an independent risk factor for executive-function impairment. The study examined 364 women between 70 and 80 years old, of whom some 10% had mild anemia. Those with anemia were four to five times more likely to perform worst on the executive function tests.

[708] Chaves, P. H. M., Carlson M. C., Ferrucci L., Guralnik J. M., Semba R., & Fried L. P.
(2006).  Association Between Mild Anemia and Executive Function Impairment in Community-Dwelling Older Women: The Women's Health and Aging Study II.
Journal of the American Geriatrics Society. 54(9), 1429 - 1435.

http://www.eurekalert.org/pub_releases/2006-09/jhmi-aab091306.php

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