Children

Children's learning & development

Children learn iconic signs more easily and quickly

December, 2012

A study of deaf toddlers suggests that we can support children’s acquisition of language by providing physical links to words, through the use of gestures, facial expressions, and tone.

The relative ease with which children acquire language has produced much debate and theory, mirroring the similar quantity of debate and theory over how we evolved language. One theory of language evolution is that it began with gesture. A recent study looking at how deaf children learn sign language might perhaps be taken as partial support for this theory, and may also have wider implications for how children acquire language and how we can best support them.

The study, involving 31 deaf toddlers, looked at 89 specific signs understood and produced by the children. It was found that both younger (11-20 months) and older (21-30 months) toddlers understood and produced more signs that were iconic than signs that were less iconic. This benefit seemed to be greater for the older toddlers, supporting the idea that a certain amount of experience and/or cognitive development is needed to make the link between action and meaning.

Surprisingly, the benefits of iconicity did not seem to depend on how familiar, phonologically complex, or imageable the words were.

In contrast to spoken language, a high proportion of signs are iconic, that is, related to the concept being expressed (such as, bringing the hand to the mouth to indicate ‘eat’). Nevertheless, if iconicity is important in sign language, it is surely also important in spoken languages. This is supported by the role of gesture in speech.

The researchers suggest that iconic links between our perceptual-motor experience of the world and the form of a sign may provide an imitation-based mechanism that supports early sign acquisition, and that this might also apply to spoken language — with gestures, tone of voice, inflection, and facial expression helping make the link between words and their meanings less arbitrary.

This suggests that we can support children’s acquisition of language by providing and emphasizing such ‘scaffolding’.

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Gender differences in effects of anxiety on performance

July, 2012

Two studies indicate that, while anxiety is present in both sexes, it only impairs performance in females.

A British study looking at possible gender differences in the effects of math anxiety involved 433 secondary school children (11-16 years old) completing customized (year appropriate) mental mathematics tests as well as questionnaires designed to assess math anxiety and (separately) test anxiety. These sources of anxiety are often confounded in research studies (and in real life!), and while they are indeed related, reported correlations are moderate, ranging from .30 to .50.

Previous research has been inconsistent as regards gender differences in math anxiety. While many studies have found significantly greater levels of math anxiety in females, many studies have found no difference, and some have even found higher levels in males. These inconsistencies may stem from differences in how math anxiety is defined or measured.

The present study looked at a rather more subtle question: does the connection between math anxiety and math performance differ by gender? Again, previous research has produced inconsistent findings.

Findings in this study were very clear: while there was no difference between boys and girls in math performance, there were marked differences in both math and test anxiety. Girls showed significantly greater levels of both. Both boys and girls showed a positive correlation between math anxiety and test anxiety, and a negative correlation between math anxiety and math performance, and test anxiety and performance. However, these relationships between anxiety and performance were stronger for girls than boys, with the correlation between test anxiety and performance being only marginally significant for boys (p<0.07), and the correlation between math anxiety and performance disappearing once test anxiety was controlled for.

In other words, greater math anxiety was linked to poorer math performance, but it was significant only for girls. Moreover, anxiety experienced by boys may simply reflect test anxiety, rather than specific math anxiety.

It is worth emphasizing that there was no gender difference in performance — that is, despite laboring under the burden of greater levels of anxiety, the girls did just as well as boys. This suggests that girls might do better than boys if they were free of anxiety. It is possible, however, that levels of anxiety didn’t actually differ between boys and girls — that the apparent difference stems from girls feeling more free to express their anxiety.

However, the finding that anxiety is greater in girls than boys is in line with evidence that anxiety (and worry in particular) is twice as prevalent in women as men, and more support for the idea that the girls are under-performing because of their anxiety comes from another recent study.

In this study, 149 college students performed a relatively simple task while their brain activity was measured. Specifically, they had to identify the middle letter in a series of five-letter groups. Sometimes the middle letter was the same as the other four ("FFFFF") while sometimes it was different ("EEFEE"). Afterward the students completed questionnaires about their anxiety and how much they worry (Penn State Worry Questionnaire and the Anxious Arousal subscale of the Mood and Anxiety Symptom Questionnaire).

Anxiety scores were significantly negatively correlated with accuracy on the task; worry scores were unrelated to performance.

Only girls who identified themselves as particularly anxious or big worriers recorded high brain activity when they made mistakes during the task (reflecting greater performance-monitoring). Although these women performed about the same as others on simple portions of the task, their brains had to work harder at it. Then, as the test became more difficult, the anxious females performed worse, suggesting worrying got in the way of completing the task.

Greater performance monitoring was not evident among anxious men.

[A reminder: these are group differences, and don't mean that all men or all women react in these ways.]

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Even babies benefit from music lessons

June, 2012

A six-month study comparing the effects of two types of infant music class shows that babies can be taught to become sensitive to musical pitch, and that musical activity can improve social and cognitive skills.

I’ve talked before about the benefits of music lessons for children — most recently, for example, how music-based training 'cartoons' improved preschoolers’ verbal IQ. Now a new study extends the findings to infants.

In the study, 6-month-old babies were randomly assigned to six months of one of two types of weekly music class. The classes lasted an hour and involved either an active or passive approach.

In the active classes, parents and infants worked together to learn to play percussion instruments and sing lullabies and action songs. The classes emphasized musical expression, listening in order to play or sing at the right time, repetition, and developing parents’ awareness of their babies’ responses. There was also a CD that they were encouraged to play at home.

In the passive classes, parents and infants listened to CDs from the Baby Einstein series while playing and interacting at art, book, ball, block, and stacking cup play stations. Parents were encouraged to take home different CDs from the collection each week.

At the end of the program, those babies attending the active classes showed an earlier sensitive to pitch. Unlike infants from the passive classes, they preferred to listen to a piano piece played in key rather than one that included notes played out of key (you can hear the two versions at http://www.psychology.mcmaster.ca/ljt/stimuli.htm). Their brains also showed larger and/or earlier responses to musical tones.

On the cognitive side, babies from the active classes also showed better early communication skills, like pointing at objects that are out of reach, or waving goodbye. Socially, these babies also smiled more, were easier to soothe, and showed less distress when things were unfamiliar or didn't go their way. It is presumed that these social skills are due to the development of better social interaction between parent and child.

The classes were run at two centers — one in a lower socioeconomic area, and one in a middle-class area. The teachers of the classes were unaware of the nature of the experiment. Before the classes began, all the babies had shown similar communication and social development and none had previously participated in other baby music classes. There was no interaction between socioeconomic status and intervention, and the results from both were then analyzed together. There were 38 families (out of an initial 49 at the beginning) who were still attending regularly at the end of the program, and 34 of these (of whom 16 were from the lower SES centre) completed the testing.

The exciting question is of course what long-term effects this ‘head-start’ will have on cognitive and social development. I hope the researchers will follow this up.

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How early environment impacts cognitive development

February, 2012

Follow-up on an early child-care program for low-income children finds long-term benefits for education and employment. A large study pinpoints the advantages children from higher-income families have over those from low-middle families. Norway shows how extending compulsory education is linked to higher IQ.

Benefits of high quality child care persist 30 years later

Back in the 1970s, some 111 infants from low-income families, of whom 98% were African-American, took part in an early childhood education program called the Abecedarian Project. From infancy until they entered kindergarten, the children attended a full-time child care facility that operated year-round. The program provided educational activities designed to support their language, cognitive, social and emotional development.

The latest data from that project, following up the participants at age 30, has found that these people had significantly more years of education than peers who were part of a control group (13.5 years vs 12.3), and were four times more likely to have earned college degrees (23% vs 6%).

They were also significantly more likely to have been consistently employed (75% had worked full time for at least 16 of the previous 24 months, compared to 53% of the control group) and less likely to have used public assistance (only 4% received benefits for at least 10% of the previous seven years, compared to 20% of the control group). However, income-to-needs ratios (income taken into account household size) didn’t vary significantly between the groups (mainly because of the wide variability; on the face of it, the means are very different, but the standard deviation is huge), and neither did criminal involvement (27% vs 28%).

See their website for more about this project.

Evidence that more time at school raises IQ

It would be interesting to see what the IQs of those groups are, particularly given that maternal IQ was around 85 for both treatment and control groups. A recent report analyzed the results of a natural experiment that occurred in Norway when compulsory schooling was increased from seven to nine years in the 1960s, meaning that students couldn’t leave until 16 rather than 14. Because all men eligible for the draft were given an IQ test at age 19, statisticians were able to look back and see what effect the increased schooling had on IQ.

They found that it had a substantial effect, with each additional year raising the average IQ by 3.7 points.

While we can’t be sure how far these results extend to other circumstances, they are clear evidence that it is possible to improve IQ through education.

Why children of higher-income parents start school with an advantage

Of course the driving idea behind improved child-care in the early years is all about the importance of getting off to a good start, and you’d expect that providing such care to children would have a greater long-term effect on IQ than simply extending time at school. Most such interventions have looked at the most deprived strata of society. An overlooked area is that of low to middle income families, who are far from having the risk factors of less fortunate families.

A British study involving 15,000 five-year-olds has found that, at the start of school, children from low to middle income families are five months behind children from higher income families in terms of vocabulary skills and have more behavior problems (they were also 8 months ahead of their lowest income peers in vocabulary).

Low-middle income (LMI) households are defined by the Resolution Foundation (who funded this research) as members of the working-age population in income deciles 2-5 who receive less than one-fifth of their gross household income from means-tested benefits (see their website for more detail on this).

Now the difference in home environment between LMI and higher income households is often not that great — particularly when you consider that it is often a difference rooted in timing. LMI households are more common in this group of families with children under five, because the parents are usually at an early stage of life. So what brings about this measurable difference in language and behavior development?

This is a tricky thing to derive from the data, and the findings must be taken with a grain of salt. And as always, interpretation is even trickier. But with this caveat, let’s see what we have. Let’s look at demographics first.

The first thing is the importance of parental education. Income plus education accounted for some 70-80% of the differences in development, with education more important for language development and income more important for behavior development. Maternal age then accounted for a further 10%. Parents in the higher-income group tended to be older and have better education (e.g., 18% of LMI mothers were under 25 at the child’s birth, compared to 6% of higher-income mothers; 30% of LMI parents had a degree compared to 67% of higher-income parents).

Interestingly, family size was equally important for language development (10%), but much less important for behavior development (in fact this was a little better in larger families). Differences in ethnicity, language, or immigration status accounted for only a small fraction of the vocabulary gap, and none of the behavior gap.

Now for the more interesting but much trickier analysis of environmental variables. The most important factor was home learning environment, accounting for around 20% of the difference. Here the researchers point to higher-income parents providing more stimulation. For example, higher-income parents were more likely to read to their 3-year-olds every day (75% vs 62%; 48% for the lowest-income group), to take them to the library at least once a month (42% vs 35% vs 26%), to take their 5-year-old to a play or concert (86% vs 75% vs 60%), to a museum/gallery (67% vs 48% vs 36%), to a sporting activity at least once a week (76% vs 57% vs 35%). Higher-income parents were also much less likely to allow their 3-year-olds to watch more than 3 hours of TV a day (7% vs 17% vs 25%). (I know the thrust of this research is the comparison between LMI and higher income, but I’ve thrown in the lowest-income figures to help provide context.)

Interestingly, the most important factor for vocabulary learning was being taken to a museum/gallery at age 5 (but remember, these correlations could go either way: it might well be that parents are more likely to take an articulate 5-year-old to such a place), with the second most important factor being reading to 3-year-old every day. These two factors accounted for most of the effects of home environment. For behavior, the most important factor was regular sport, followed by being to a play/concert, and being taken to a museum/gallery. Watching more than 3 hours of TV at age 3 did have a significant effect on both vocabulary and behavior development (a negative effect on vocabulary and a positive effect on behavior), while the same amount of TV at age 5 did not.

Differences in parenting style explained 10% of the vocabulary gap and 14% of the behavior gap, although such differences were generally small. The biggest contributors to the vocabulary gap were mother-child interaction score at age 3 and regular bedtimes at age 3. The biggest contributors to the behavior gap were regular bedtimes at age 5, regular mealtimes at age 3, child smacked at least once a month at age 5 (this factor also had a small but significant negative effect on vocabulary), and child put in timeout at least once a month at age 5.

Maternal well-being accounted for over a quarter of the behavior gap, but only a small proportion of the vocabulary gap (2% — almost all of this relates to social support score at 9 months). Half of the maternal well-being component of the behavior gap was down to psychological distress at age 5 (very much larger than the effect of psychological distress at age 3). Similarly, child and maternal health were important for behavior (18% in total), but not for vocabulary.

Material possessions, on the other hand, accounted for some 9% of the vocabulary gap, but none of the behavior gap. The most important factors here were no internet at home at age 5 (22% of LMIs vs 8% of higher-incomes), and no access to a car at age 3 (5% of LMIs had no car vs 1% of higher incomes).

As I’ve intimated, it’s hard to believe we can disentangle individual variables in the environment in an observational study, but the researchers believe the number of variables in the mix (158) and the different time points (many variables are assessed at two or more points) provided a good base for analysis.

Reference: 

[2676] Campbell, F. A., Pungello E. P., Burchinal M., Kainz K., Pan Y., Wasik B. H., et al.
(2012).  Adult outcomes as a function of an early childhood educational program: An Abecedarian Project follow-up.
Developmental Psychology;Developmental Psychology. No Pagination Specified - No Pagination Specified.

[2675] Brinch, C. N., & Galloway T A.
(2012).  Schooling in adolescence raises IQ scores.
Proceedings of the National Academy of Sciences. 109(2), 425 - 430.

Washbrook, E., & Waldfogel, J. (2011). On your marks : Measuring the school readiness of children in low-to-middle income families. Resolution Foundation, December 2011.

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How family circumstance impacts learning and memory in children

February, 2012

A large study shows the impact of having multiple family disadvantages on cognitive development. A brain scan study finds childhood maltreatment significantly reduces the size of the hippocampus, while another finds parental care can increase it.

Quarter of British children performing poorly due to family disadvantage

A British study involving over 18,000 very young children (aged 9 months to 5 years) has found that those exposed to two or more “disadvantages” (28% of the children) were significantly more likely to have impaired intellectual development, expressed in a significantly reduced vocabulary and behavioral problems.

These differences were significant at three, and for the most part tended to widen between ages three or five (cognitive development, hyperactivity, peer problems and prosocial behaviors; the gap didn’t change for emotional problems, and narrowed for conduct problems). However, only the narrowing of the conduct problem gap and the widening of the peer problem gap was statistically significant.

Ten disadvantages were identified: living in overcrowded housing; having a teenage mother; having one or more parents with depression, parent with a physical disability; parent with low basic skills; maternal smoking during pregnancy; excessive alcohol intake; financial stress, unemployment; domestic violence..

Around 41% of the children did not face any of these disadvantages, and 30% faced only one of these disadvantages. Of those facing two or more, half of those (14%) only had two, while 7% of the total group experienced three risk factors, and fewer than 2% had five or more.

There was no dominant combination of risks, but parental depression was the most common factor (19%), followed by parental disability (15%). Violence was present in only 4% of families, and both parents unemployed in only 5.5%. While there was some correlation between various risk factors, these correlations were relatively modest for the most part. The highest correlations were between unemployment and disability; violence and depression; unemployment and overcrowding.

There were ethnic differences in rate: at 48%, Bangladeshi children were most likely to be exposed to multiple disadvantages, followed by Pakistani families (34%), other (including mixed) (33%), black African (31%), black Caribbean (29%), white (28%) and Indian (20%).

There were also differences depending on family income. Among those in the lowest income band (below £10,400 pa) — into which 21% of the families fell, the same proportion as is found nationally — nearly half had at least two risk factors, compared to 27% of those in families above this threshold. Moreover, children in families with multiple risk factors plus low income showed the lowest cognitive development (as measured by vocabulary).

Childhood maltreatment reduces size of hippocampus

In this context, it is interesting to note a recent finding that three key areas of the hippocampus were significantly smaller in adults who had experienced maltreatment in childhood. In this study, brain scans were taken of nearly 200 young adults (18-25), of whom 46% reported no childhood adversity and 16% reported three or more forms of maltreatment. Maltreatment was most commonly physical and verbal abuse from parents, but also included corporal punishment, sexual abuse and witnessing domestic violence.

Reduced volume in specific hippocampus regions (dentate gyrus, cornu ammonis, presubiculum and subiculum) was still evident after such confounding factors as a history of depression or PTSD were taken into account. The findings support the theory that early stress affects the development of subregions in the hippocampus.

While mother’s nurturing grows the hippocampus

Supporting this, another study, involving 92 children aged 7 to 10 who had participated in an earlier study of preschool depression, has found that those children who received a lot of nurturing from their parent (generally mother) developed a larger hippocampus than those who didn’t.

‘Nurturing’ was assessed in a videotaped interaction at the time of the preschool study. In this interaction, the parent performed a task while the child waited for her to finish so they could open an attractive gift. How the parent dealt with this common scenario — the degree to which they helped the child through the stress — was evaluated by independent raters.

Brain scans revealed that children who had been nurtured had a significantly larger hippocampus than those whose mothers were not as nurturing, and (this was the surprising bit), this effect was greater among the healthy, non-depressed children. Among this group, those with a nurturing parent had hippocampi which were on average almost 10% larger than those whose parent had not been as nurturing.

Reference: 

First study:
Sabates, R., Dex, S., Sabates, R., & Dex, S. (2012). Multiple risk factors in young children’s development. CLS Cohort Studies Working paper 2012/1.
Full text available at http://www.cls.ioe.ac.uk/news.aspx?itemid=1661&itemTitle=More+than+one+i...

Second study:
[2741] Teicher, M. H., Anderson C. M., & Polcari A.
(2012).  Childhood maltreatment is associated with reduced volume in the hippocampal subfields CA3, dentate gyrus, and subiculum.
Proceedings of the National Academy of Sciences.
Full text available at http://www.pnas.org/content/early/2012/02/07/1115396109.abstract?sid=f73...

Third study:
[2734] Luby, J. L., Barch D. M., Belden A., Gaffrey M. S., Tillman R., Babb C., et al.
(2012).  Maternal support in early childhood predicts larger hippocampal volumes at school age.
Proceedings of the National Academy of Sciences.

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Myths about gender and math performance

January, 2012

Two new reviews debunk several theories for the reasons for gender gaps in math performance.

Is there, or is there not, a gender gap in mathematics performance? And if there is, is it biological or cultural?

Although the presence of a gender gap in the U.S. tends to be regarded as an obvious truth, evidence is rather more equivocal. One meta-analysis of studies published between 1990 and 2007, for example, found no gender differences in mean performance and nearly equal variability within each gender. Another meta-analysis, using 30 years of SAT and ACT scores, found a very large 13:1 ratio of middle school boys to girls at the highest levels of performance in the early 1980s, which declined to around 4:1 by 1991, where it has remained. A large longitudinal study found that males were doing better in math, across all socioeconomic classes, by the 3rd grade, with the ratio of boys to girls in the top 5% rising to 3:1 by 5th grade.

Regardless of the extent of any gender differences in the U.S., the more fundamental question is whether such differences are biological or cultural. The historical changes mentioned above certainly point to a large cultural component. Happily, because so many more countries now participate in the Trends in International Mathematics and Science Study (TIMSS) and the Programme in International Student Assessment (PISA), much better data is now available to answer this question. In 2007, for example, 4th graders from 38 countries and 8th graders from 52 countries participated in TIMSS. In 2009, 65 countries participated in PISA.

So what does all this new data reveal about the gender gap? Overall, there was no significant gender gap in the 2003 and 2007 TIMSS, with the exception of the 2007 8th graders, where girls outperformed boys.

There were, of course, significant gender gaps on a country basis. Researchers looked at several theories for what might underlie these.

Contradicting one theory, gender gaps did not correlate reliably with gender equity. In fact, both boys and girls tended to do better in math when raised in countries where females have better equality. The primary contributor to this appears to be women’s income and rates of participation in the work force. This is in keeping with the idea that maternal education and employment opportunities have benefits for their children’s learning regardless of gender.

The researchers also looked at the more specific hypothesis put forward by Steven Levitt, that gender inequity doesn’t hurt girls' math performance in Muslim countries, where most students attend single-sex schools. This theory was not borne out by the evidence. There was no consistent link between school type and math performance across countries.

However, math performance in the 29 wealthier countries could be predicted to a very high degree by three factors: economic participation and opportunity; GDP per capita; membership of one of three clusters — Middle Eastern (Bahrain, Kuwait, Oman, Qatar, Saudi Arabia); East Asian (Hong Kong, Japan, South Korea, Singapore, Taiwan); rest (Russia, Hungary, Czech Republic, England, Canada, US, Australia, Sweden, Norway, Scotland, Cyprus, Italy, Malta, Israel, Spain, Lithuania, Malaysia, Slovenia, Dubai). The Middle Eastern cluster scored lowest (note the exception of Dubai), and the East Asian the highest. While there are many cultural factors differentiating these clusters, it’s interesting to note that countries’ average performance tended to be higher when students attribute less importance to mastering math.

The investigators also looked at the male variability hypothesis — the idea that males are more variable in their performance, and their predominance at the top is balanced by their predominance at the bottom. The study found however that greater male variation in math achievement varies widely across countries, and is not found at all in some countries.

In sum, the cross-country variability in performance in regard to gender indicates that the most likely cause of any differences lies in country-specific social factors. These could include perception of abilities as fixed vs malleable, attitude toward math, gender beliefs.

Stereotype threat

A popular theory of women’s underachievement in math concerns stereotype threat (first proposed by Spencer, Steele, and Quinn in a 1999 paper). I have reported on this on several occasions. However, a recent review of this research claims that many of the studies were flawed in their methodology and statistical analysis.

Of the 141 studies that cited the original article and related to mathematics, only 23 met the criteria needed (in the reviewers’ opinion) to replicate the original study:

  • Both genders tested
  • Math test used
  • Subjects recruited regardless of preexisting beliefs about gender stereotypes
  • Subjects randomly assigned to experimental conditions

Of these 23, three involved younger participants (< 18 years) and were excluded. Of the remaining 20 studies, only 11 (55%) replicated the original effect (a significant interaction between gender and stereotype threat, and women performing significantly worse in the threat condition than in the threat condition compared to men).

Moreover, half the studies confounded the results by statistically adjusting preexisting math scores. That is, the researchers tried to adjust for any preexisting differences in math performance by using a previous math assessment measure such as SAT score to ‘tweak’ the baseline score. This practice has been the subject of some debate, and the reviewers come out firmly against it, arguing that “an important assumption of a covariate analysis is that the groups do not differ on the covariate. But that group difference is exactly what stereotype threat theory tries to explain!” Note, too, that the original study didn’t make such an adjustment.

So what happens if we exclude those studies that confounded the results? That leaves ten studies, of which only three found an effect (and one of these found the effect only in a subset of the math test). In other words, overwhelmingly, it was the studies that adjusted the scores that found an effect (8/10), while those that didn’t adjust them didn’t find the effect (7/10).

The power of the adjustment in producing the effect was confirmed in a meta-analysis.

Now these researchers aren’t saying that stereotype threat doesn’t exist, or that it doesn’t have an effect on women in this domain. Their point is that the size of the effect, and the evidence for the effect, has come to be regarded as greater and more robust than the research warrants.

At a practical level, this may have led to too much emphasis on tackling this problem at the expense of investigating other possible causes and designing other useful interventions.

Reference: 

Kane, J. M., & Mertz, J. E. (2012). Debunking Myths about Gender and Mathematics Performance. Notices of the AMS, 59(1), 10-21.

[2698] Stoet, G., & Geary D. C.
(2012).  Can stereotype threat explain the gender gap in mathematics performance and achievement?.
Review of General Psychology;Review of General Psychology. No Pagination Specified - No Pagination Specified.

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IQ can rise or fall significantly during adolescence

November, 2011

A small study of adolescents shows marked variability in IQ over a four-year period for many of them. This variability correlated with specific changes in the brain.

IQ has long been considered to be a fixed attribute, stable across our lifetimes. But in recent years, this assumption has come under fire, with evidence of the positive and negative effects education and experiences can have on people’s performance. Now a new (small) study provides a more direct challenge.

In 2004, 33 adolescents (aged 12-16) took IQ tests and had their brains scanned. These tests were repeated four years later. The teenagers varied considerably in their levels of ability (77-135 in 2004; 87-143 in 2008). While the average IQ score remained the same (112; 113), there were significant changes in the two IQ scores for some individuals, with some participants gaining as much as 21 points, and others falling as much as 18 points. Clear change in IQ occurred for a third of the participants, and there was no obvious connection to specific attributes (e.g., low performers didn’t get better while high performers got worse).

These changes in performance correlated with structural changes in the brain. An increase in verbal IQ score correlated with an increase in the density of grey matter in an area of the left motor cortex of the brain that is activated when articulating speech. An increase in non-verbal IQ score correlated with an increase in the density of grey matter in the anterior cerebellum, which is associated with movements of the hand. Changes in verbal IQ and changes in non-verbal IQ were independent.

While I’d really like to see this study repeated with a much larger sample, the findings are entirely consistent with research showing increases in grey matter density in specific brain regions subsequent to specific training. The novel part of this is the correlation with such large changes in IQ.

The findings add to growing evidence that teachers shouldn’t be locked into beliefs about a student’s future academic success on the basis of past performance.

Postscript: I should perhaps clarify that IQ performance at each of these time points was age-normed - this is not a case of children just becoming 'smarter with age'.

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Lead

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

Children

School-age lead exposures most harmful to IQ

A number of studies have connected higher blood concentration of lead in toddlers with reduced IQ at school age. Now data from two points — children in Cincinnati during the early 1980s; children Rochester, N.Y., during the mid-1990s — has revealed confirmed earlier indications that IQ losses are most predictable from comparisons of a child’s blood-lead level at age 6 compared to the level at age 2, and that the level at age 5-6 is more important than that at age 2 (although that is when most testing is done). Lead-level at age 6 also correlated with reduced brain tissue in certain brain regions in adulthood, especially in those regions relating to judgment, self-control, and mood (and an increased level of criminal behavior).

[509] Hornung, R. W., Lanphear B. P., & Dietrich K. N.
(2009).  Age of Greatest Susceptibility to Childhood Lead Exposure: A New Statistical Approach.
Environmental Health Perspectives.

http://www.sciencenews.org/view/generic/id/43795/title/School-age_lead_exposures_most_harmful_to_IQ

Children more vulnerable to harmful effects of lead

A study has found that children are more vulnerable to the harmful effects of lead at age 6 than they at younger ages. The study found that children's average blood lead concentrations peaked at 13.9 micrograms of lead per deciliter of blood at age 2, then declined to an average of 7.3 micrograms per deciliter by age 6. For children with the same average blood lead levels through age 6, however, those who received more of their exposure at age 6 had substantially greater decrements in intellectual ability (with lower IQ and reduced volume of gray matter in the prefrontal cortex) than those more heavily exposed at age 2. The Centers for Disease Control and Prevention recommends public health actions be initiated at blood lead levels greater than 10 micrograms per deciliter, despite lower levels being consistently shown to be associated with adverse effects.

The Cincinnati Children's Hospital Medical Center study was presented May 4, 2008, at the annual meeting of the Pediatric Academic Societies in Honolulu.

http://www.physorg.com/news129129066.html
http://www.eurekalert.org/pub_releases/2008-05/cchm-cmv050108.php

Early lead exposure impedes later recovery from brain injury

We know that lead exposure in early years can affect the brain. We also know that it increases the risk of various disorders later in life. Now a rat study reveals that animals exposed to lead earlier in life were significantly less able to recover from an induced stroke than those not so exposed. The study only looked at a short time-frame, so it is not yet known if the lead-exposed animals would catch up in their recovery in a longer period of time. There was some recovery in the lead group, but then it leveled off. The control group continued to get better. The findings support the suggestion that lead poisoning impairs neural plasticity.

[698] Schneider, J. S., & Decamp E.
(2007).  Postnatal lead poisoning impairs behavioral recovery following brain damage.
Neurotoxicology. 28(6), 1153 - 1157.

http://www.eurekalert.org/pub_releases/2007-12/tju-jnf120307.php

ADHD linked to genetic and environmental interactions

A study of 172 children who were enrolled in a community-based study of low levels of lead exposure has found evidence that increasing lead exposure is linked to impairment on a number of executive functions (impaired in those with ADHD), but that certain genetic and biological factors seemed to predispose an individual to the negative effects of lead exposure. For instance, only children with certain variations of the DRD4 gene seemed vulnerable to lead's adverse effects on attentional flexibility. Boys were more vulnerable to this effect than girls.

The study was presented on May 1, 2006, at the annual Pediatric Academic Societies meeting in San Francisco.

http://www.eurekalert.org/pub_releases/2006-05/cchm-sla042606.php

Lead exposure may affect recovery from brain injury

Lead exposure at a young age can hurt the brain's development and cause learning and behavioral problems. Now it seems that it might also affect a child’s ability to recover from brain injury. A new study found young rats exposed to low levels of lead took significantly longer to recover from a brain injury than those animals that weren't lead-exposed, as well as recovering less well.

Dr. Schneider presented the findings Oct. 25, 2004, at the Society for Neuroscience's annual meeting in San Diego.

http://www.eurekalert.org/pub_releases/2004-10/tju-jnf102404.php

Environmental damage to brains of children

A new report suggests that the brains of children in many parts of Europe are suffering greater damage from environmental risks than previously recognized. A meeting in Malta of European delegates preparing for a ministerial conference on environment and health, being held in Budapest in June, were given preliminary results from a comprehensive study on environmental threats to children's health, being conducted by the WHO and the University of Udine, Italy. The full report is to be published at the Budapest conference. The findings suggest lead is the single most important damaging chemical for children. In 2001, the estimated percentage of European children in urban areas with elevated blood levels (above 10 micrograms per decilitre) ranged from 0.1% to 30.2%.

http://news.bbc.co.uk/1/hi/sci/tech/3568939.stm

Pros and cons of therapy for lead exposure

Lead chelation therapy is widely used to treat lead-exposed children, and is increasingly being used for the treatment of autism in children. However, a rat study has now found that, although the treatment can indeed significantly reduce learning and behavioral problems that result from lead exposure, when rats with no lead in their systems were treated, they showed declines in their learning and behavior that were similar to the rats that were exposed to lead. The findings suggest that lead chelation therapy should only be used, as recommended, for children with at least moderate lead exposure.

[429] Stangle, D. E., Smith D. R., Beaudin S. A., Strawderman M. S., Levitsky D. A., & Strupp B. J.
(2006).  Succimer Chelation Improves Learning, Attention, and Arousal Regulation in Lead-Exposed Rats but Produces Lasting Cognitive Impairment in the Absence of Lead Exposure.
Environmental Health Perspectives. 115(2), 201 - 209.

http://www.eurekalert.org/pub_releases/2006-12/cuns-csr121306.php

Adults

Workers exposed to lead show more cognitive problems later in life

A follow-up of the 1982 Lead Occupational Study, which assessed the cognitive abilities of 288 lead-exposed and 181 non-exposed male workers in eastern Pennsylvania, has found that among the lead-exposed workers, those with higher cumulative lead had significantly lower cognitive scores. The clearest inverse relationships were between cumulative lead and spatial ability, learning and memory, and overall cognitive score. This linkage was more significant in the older lead-exposed men (55 years and older). Their cognitive scores were significantly different from those of younger lead-exposed men even when the researchers controlled for current blood levels of lead. In other words, even when men no longer worked at the battery plants, their earlier prolonged exposure was enough to matter.

[406] Khalil, N., Morrow L. A., Needleman H., Talbott E. O., Wilson J. W., & Cauley J. A.
(2009).  Association of cumulative lead and neurocognitive function in an occupational cohort.
Neuropsychology. 23(1), 10 - 19.

Full text available at http://www.apa.org/journals/releases/neu23110.pdf
http://www.eurekalert.org/pub_releases/2009-01/apa-wet010709.php

Reading ability protects brain from lead exposure

Cognitive reserve is a concept that has been chiefly discussed in terms of protecting against age-related cognitive decline and Alzheimer’s, but a new study has found evidence that it can also protect against long-term lead exposure. The study of 112 smelter workers found that the cognitive effects of lead were 2.5 times greater in workers with low reading ability, compared to those with high reading ability (defined as a reading level of 12th grade or higher). Motor speed, however, was comparable in both groups — demonstrating that the nervous system was impaired similarly in both groups.

[258] Bleecker, M. L., Ford D. P., Celio M. A., Vaughan C. G., & Lindgren K. N.
(2007).  Impact of cognitive reserve on the relationship of lead exposure and neurobehavioral performance.
Neurology. 69(5), 470 - 476.

http://www.eurekalert.org/pub_releases/2007-07/aaon-rap072407.php

Long-term lead exposure linked to cognitive decline in older adults

A study of nearly a thousand randomly selected Baltimore residents, all between 50 and 70 years old and consequently exposed to higher levels of lead prior to the 1980s when lead was used extensively in commercial products, has revealed higher lead levels in the bone were consistently associated with worse cognitive performance on tests, equivalent to two to six years of aging. Blood lead levels were not associated with a difference in cognitive performance. The study also found bone lead levels were significantly higher in African Americans compared to Caucasians.

[845] Shih, R. A., Glass T. A., Bandeen-Roche K., Carlson M. C., Bolla K. I., Todd A. C., et al.
(2006).  Environmental lead exposure and cognitive function in community-dwelling older adults.
Neurology. 67(9), 1556 - 1562.

http://www.eurekalert.org/pub_releases/2006-09/aaon-lle091306.php

Lead exposure leads to brain cell loss and damage years later

A study of 532 former employees of a chemical manufacturing plant who had not been exposed to lead for an average of 18 years has found that the higher their lead levels were, the more likely they were to have smaller brain volumes and greater amounts of brain damage. 36% had white matter lesions. The results confirm earlier findings in this same population that people with occupational lead exposure experience declines in their thinking and memory skills years after their exposure.

[514] Youssem, D., Stewart W. F., Schwartz B. S., Davatzikos C., Shen D., Liu D., et al.
(2006).  Past adult lead exposure is linked to neurodegeneration measured by brain MRI.
Neurology. 66(10), 1476 - 1484.

http://www.eurekalert.org/pub_releases/2006-05/aaon-lel051806.php

tags lifestyle: 

Autism

Additional brief reports

Genes for autism and schizophrenia only active in developing brains

February 11, 2013

Genes linked to autism and schizophrenia are only switched on during the early stages of brain development, according to a study in mice.

It has been suspected for a long time that if the development of the cortex is disrupted by genetic abnormalities or environmental stress (such as prematurity) this would have long-lasting adverse effects on brain development and could lead to problems like ADHD or autism. This study defines genes that are important in mice at this critical period and this does indeed seem to include genes known to predispose to autism and schizophrenia.

http://medicalxpress.com/news/2013-02-genes-autism-schizophrenia-brains.html

Scientists investigate inherited causes of autism

February 4, 2013

Two new studies investigate the role recessive genes play in ASD. These genes can be passed on through generations, but their effects are seen only if an individual inherits two identical copies of the gene – one from each parent.

One study found that approximately 5% of autism cases could be linked to inherited, recessive mutations that completely disrupt gene function. A second study found that autism risk could also be attributed to inherited mutations that resulted in only a partial loss of gene function.

The number of different genetic mutations uncovered by the two studies supports the long-held theory that autism is a heterogeneous condition with many different genetic causes.

http://medicalxpress.com/news/2013-02-scientists-inherited-autism.html

Gene target shows promise for autism

January 3, 2013

Mouse study found that chemically normalizing excessive levels of protein synthesis induced by a variant of the EIF4E gene, whose mutation is associated with autism, significantly reduced autistic-like behaviors. The mice were less likely to engage in repetitive behaviors, more likely to interact with other mice, and were successful in navigating mazes that differed from those they previously solved.

http://www.futurity.org/health-medicine/gene-target-shows-promise-for-autism/

Air pollution drives up autism risk

Exposure to traffic-related air pollution during pregnancy and the first year of life was associated with a more than two-fold risk of autism. Exposure to regional pollution was also associated with autism even if the mother did not live near a busy road.

http://www.futurity.org/health-medicine/air-pollution-drives-up-autism-risk/

note criticism of the study: http://www.forbes.com/sites/emilywillingham/2012/11/27/5-caveats-about-the-autism-and-air-pollution-study/

Autism risk test is 70% accurate

September 12, 2012

A new genetic test predicted a person’s risk of developing an autism spectrum disorder with over 70% accuracy. Participants were all of central European descent. The test uses 237 genetic markers (SNPs) in 146 genes and related cellular pathways.

http://www.futurity.org/health-medicine/autism-risk-test-is-70-percent-accurate/

Unreliable neural response in autistic adults

September 20, 2012

A small study shows that autistic adults have unreliable neural sensory responses to visual, auditory, and somatosensory, or touch, stimuli. This poor response reliability appears to be a fundamental neural characteristic of autism. Non-autistic individuals showed reliably consistent brain activity to sensory information, while autistic individuals showed marked trial-by-trial variability. It’s suggested that such unreliable activity might be what’s limiting the development of social and language abilities.

http://www.futurity.org/health-medicine/unreliable-neural-response-in-autistic-adults/

Electrical Activity in the Brain Can Distinguish Children With Autism

June 27, 2012

A large study found that patterns of electrical activity in the brain can distinguish children with autism from children with typical brains as early as age 2. In general, autistic children showed reduced connectivity.

http://blogs.edweek.org/edweek/speced/2012/06/electrical_activity_in_the_brain_can.html

Autism and schizophrenia may share root cause

July 3, 2012

The risk of an autism spectrum disorder may be higher among people whose parents or siblings have been diagnosed with schizophrenia or bipolar disorder.

The presence of schizophrenia in parents was associated with an almost three times increased risk for autism spectrum disorders in Swedish groups. Schizophrenia in a sibling also was associated with roughly two and a half times the risk for autism in the Swedish national group and a 12 times greater risk in a sample of Israeli military conscripts (perhaps because of individuals with earlier onset schizophrenia, “which has a higher sibling recurrence”).

Bipolar disorder showed a similar pattern of association but of a lesser magnitude, study results indicate.

http://www.futurity.org/health-medicine/autism-and-schizophrenia-may-share-root-cause/

The ‘autism epidemic’ and diagnostic substitution

Excellent article on the question of why there’s been such an increase in autism diagnoses. The researcher makes a strong case that it is because of changes in diagnosis rather than a true increase.

http://deevybee.blogspot.com/2012/06/autism-epidemic-and-diagnostic.html

Oxytocin improves brain function in children with autism

Preliminary results from an ongoing, large-scale study shows that oxytocin increased brain function in regions that are known to process social information in children and adolescents with autism spectrum disorders.

http://www.eurekalert.org/pub_releases/2012-05/yu-oib051812.php

Research shows how PCBs promote dendrite growth, may increase autism risk

New research shows that PCBs, or polychlorinated biphenyls, launch a cellular chain of events that leads to an overabundance of dendrites and disrupts normal patterns of neuronal connections in the brain. "Impaired neuronal connectivity is a common feature of a number of conditions, including autism spectrum disorders." It’s suggested that PCB exposure "may increase the likelihood of autism in children whose genetic makeup already compromises the processes by which neurons form connections."

http://www.eurekalert.org/pub_releases/2012-04/uoc--rsh042512.php

http://www.futurity.org/health-medicine/toxic-pcbs-scramble-brain-connections/

Full text available at http://ehp03.niehs.nih.gov/article/info%3Adoi%2F10.1289%2Fehp.1104833

Protein in overdrive links to autism

March 21, 2012

A mouse study suggests that early disruptions in serotonin signaling in the brain may contribute to autism spectrum disorder. It has long been known that many children with autism have elevated blood levels of serotonin (hyperserotonemia).

http://www.futurity.org/health-medicine/serotonin-in-overdrive-links-to-autism/

People with autism possess greater ability to process information, study suggests

A small study suggests that people with autism spectrum disorders have a greater than normal capacity for processing perceptual information even from rapid presentations and are better able to detect information defined as 'critical'.

http://www.eurekalert.org/pub_releases/2012-03/wt-pwa032212.php

Autism mutations, scattered across many genes, merge into common network of interactions

A large study looking at the genes of children with sporadic autism" (no family history) has found that many mutations related to modifying chromatin (the tightly coiled spools of DNA in the cell), changing the way DNA is packaged. They also found that new mutations were overwhelming paternal in origin (in a ratio of 4:1), that the new mutations occurred at a rate that correlated with the age of the father.

What is also very clear from this and other recent studies is that autism risk mutations are scattered across many genes. It’s suggested that although no single gene will account for more than 1% of autism cases, collectively all of these rare mutations will account for much of the genetic basis of the disease.

http://www.eurekalert.org/pub_releases/2012-04/uow-ams040212.php

Evolution's gift may also be at the root of a form of autism

May 10th, 2012

A study has identified the evolutionary changes that led the NOS1 gene to become active specifically in the parts of the developing human brain that form the adult centers for speech and language and decision-making. This pattern of NOS1 activity is controlled by a protein called FMRP and is missing in Fragile X syndrome. Fragile X syndrome, the leading inherited form of intellectual disability, is also the most common single-gene cause of autism.

http://medicalxpress.com/news/2012-05-evolution-gift-root-autism.html

Researchers discover new genes contributing to autism, links to psychiatric disorders

April 19th, 2012

A new approach to investigating hard-to-find chromosomal abnormalities has identified 33 genes associated with autism and related disorders, 22 for the first time. Several of these genes also appear to be altered in different ways in individuals with psychiatric disorders such as schizophrenia.

http://medicalxpress.com/news/2012-04-genes-contributing-autism-links-psychiatric.html

RNA discovery offers clue in autism puzzle

April 5, 2012

Scientists have discovered the first gene associated with autism that has genome-wide significance. Expression of MSNP1AS was increased 12-fold in the brains of people with autism. This gene controls expression of a protein called moesin, which influences brain development and immune response.

http://www.futurity.org/health-medicine/rna-discovery-offers-clue-in-autism-puzzle/

Study identifies gene expression abnormalities in autism

March 22nd, 2012

Following previous research showing a link between autism and excess brain cells in the prefrontal cortex, a study has showed that genetic mechanisms that normally regulate the number of cortical neurons are abnormal in such cases. This abnormality may not only result in too many neurons in some regions, but not enough in others.

Moreover, while the adolescent prefrontal cortex showed dysregulation in the pathways that govern cell number, cortical patterning and cell differentiation, adults showed dysregulation of signaling and repair pathways — indicating that gene expression abnormalities change across the lifespan in autism.

http://medicalxpress.com/news/2012-03-gene-abnormalities-autism.html

With autism, altered white matter in brain

March 7, 2012

Brain imaging and computer modeling shows how autistic brains tend to have poor quality white matter tracts connecting the frontal and posterior regions of the brain. This may explain social and language impairments.

This may mean that appropriate training could improve the white matter — compromised white matter in children with reading difficulties has been shown to be reparable with extensive behavioral therapy.

http://www.futurity.org/health-medicine/with-autism-altered-white-matter-in-brain/

Autism can be detected in babies, say scientists

A study involving six- to 10-month-old babies who had an older brother or sister with autism found that brain activity while the infants were shown faces that switched between looking at them or away from them was indicative of later diagnoses of autism.

http://www.guardian.co.uk/society/2012/jan/27/autism-detected-babies-say-scientists

http://www.eurekalert.org/pub_releases/2012-01/cp-itb012012.php

Neuroscientists find that two rare autism-related disorders are caused by opposing malfunctions in the brain

November 24, 2011

Most cases of autism are not caused by a single genetic mutation. However, several disorders with autism-like symptoms, including the rare Fragile X syndrome, can be traced to a specific mutation that leads to overproduction of proteins found in brain synapses. A new study shows that tuberous sclerosis, another rare disease characterized by autism and mental retardation, is caused by the opposite malfunction — too little synthesis of those synaptic proteins.

The findings fit into the theory that autism can be caused by a wide range of brain-synapse glitches. “The general concept is that appropriate brain function occurs within a very narrow physiological range that is tightly maintained. If you exceed that range in either direction, you have an impairment that can manifest as this constellation of symptoms, which very frequently go together — autism spectrum disorder, intellectual disability and epilepsy.”

The findings also show that not all cases of autism spectrum disorder will respond to the same kind of treatment.

http://medicalxpress.com/news/2011-11-neuroscientists-rare-autism-related-disorders-opposing.html

Research reveals autistic individuals are in fact superior in multiple areas

Articles about neurocentrism etc

http://medicalxpress.com/news/2011-11-reveals-autistic-individuals-fact-superior.html

http://www.nature.com/nature/journal/v479/n7371/full/479033a.html

http://www.nature.com/nature/journal/v479/n7371/full/479005a.html

http://www.guardian.co.uk/science/neurophilosophy/2011/oct/07/1

http://www.scientificamerican.com/article.cfm?id=the-hidden-potential-of-autistic-kids

Researchers find alterations of a single gene associated with intellectual disability, epilepsy and autistic features

October 7, 2011

A study has identified the gene MBD5 as the sole causative gene for 2q23.1 deletion syndrome. MBD5 functions in regulating the expression of many genes and is responsible for the core clinical features in these individuals, including intellectual disability, epilepsy and autism spectrum disorder. They have also shown that there is an association between autism and MBD5.

http://medicalxpress.com/news/2011-10-gene-intellectual-disability-epilepsy-autistic.html

New evidence for genetic basis of autism found

October 3, 2011

Some children with autism have a small deletion on chromosome 16, affecting 27 genes in a region of our genomes referred to as 16p11.2. The deletion -- which causes children to inherit only a single copy of the 27-gene cluster -- is one of the most common copy number variations (CNVs) associated with autism. A new study has found that deleting this set of genes in mice produces autistic-like behaviors: hyperactivity, difficulty adapting to a new environment, sleeping deficits, and restricted, repetitive behaviors.

http://medicalxpress.com/news/2011-10-evidence-genetic-basis-autism.html

Prenatal SSRI Exposure Linked to Autism Spectrum Disorder

A study suggests that use of selective serotonin reuptake inhibitors (SSRIs) during pregnancy increases the risk of autism spectrum disorder.

http://dx.doi.org/10.1001/archgenpsychiatry.2011.73

Inflexibility may give pupils with autism problems in multitasking

A study finds that young people with autism are inflexible when given multiple tasks, sticking rigidly to tasks in the order they are given to them, even when changing the order could save them time. They also had more difficulty remembering all the tasks they had to do.

http://www.eurekalert.org/pub_releases/2011-08/uos-img081511.php

The Risk of Aging Fathers

August 30, 2011

A mouse study has found that older males sire offspring with more copy number mutations in gene regions associated with developmental disorders, perhaps explaining why the children of older men have higher rates of schizophrenia and autism than those with younger fathers.

http://the-scientist.com/2011/08/30/the-risk-of-aging-fathers/

Diagnosed autism is more common in an IT-rich region

June 20, 2011

A Dutch study comparing prevalence of autism spectrum disorders in three geographical regions has found that diagnosed autism was significantly higher conditions in the IT-intensive region of Eindhoven (229 per 10,000, vs 84 per 10,000 and 57 per 10,000 in IT-lower regions — Haarlem and Utrecht).

http://medicalxpress.com/news/2011-06-autism-common-it-rich-region.html

Balance tips toward environment as heritability ebbs in autism?

July 4, 2011

A large twin study found that shared environmental factors accounted for 55% of strict autism and 58% of more broadly defined autism spectrum disorders (ASD). Genetic heritability accounted for 37% of autism and 38% of ASD. This dramatically reduces previous estimates of genetic heritability of autism from twin studies.

http://medicalxpress.com/news/2011-07-environment-heritability-ebbs-autism.html

Gene linked to severity of autism's social dysfunction

April 6, 2011

Variants in the gene GRIP1 (glutamate receptor interacting protein 1) have been found to contribute to the severity of social interaction deficits in autistic individuals. This gene regulates how fast receptors travel to a cell's surface, where they are activated by a brain-signaling chemical called glutamate, allowing neurons to communicate with one another. The finding lends support to a prevailing theory that autism spectrum disorders reflect an imbalance between inhibitory and excitatory signaling at synapses.

http://www.physorg.com/news/2011-04-gene-linked-severity-autism-social.html

Why Autism Strikes More Boys Than Girls

July 19, 2011

The marked gender imbalance in autism may related to a gene called retinoic acid–related orphan receptor-alpha (RORA), which interacts with certain types of estrogen and testosterone found in the brain. Autistic individuals tend to have low levels of RORA protein and the enzyme it produces (arom­a­tase). This enzyme converts testosterone to estrogen, but RORA is less active in the presence of tes­tosterone made RORA, and more active in the presence of estrogen. While the balance of sex hormones usually regulates RORA activity, an imbalance can be exacerbated by this feedback loop.

It’s suggested that low levels of RORA protein and enzyme result in an excess of testosterone, while most females are protected by their higher levels of estrogen.

http://www.scientificamerican.com/article.cfm?id=why-autism-strikes-more-boys-than-girls

'Most adults with autism go undiagnosed' -- new findings

The first ever general population survey of autism in adulthood has found that 9.8 per thousand adults in England meet official diagnostic criteria for autism spectrum disorder. Moreover, none of the cases with autism found knew that they were autistic or had received an official diagnosis of autism or asperger syndrome. The findings add support to the theory that autism is not increasing, diagnosis is just more common.

http://www.eurekalert.org/pub_releases/2011-05/uol-aw050411.php

Autism linked to hundreds of spontaneous genetic mutations

June 9. 2011

The most comprehensive search yet for spontaneous genetic mutations associated with autism spectrum disorders suggests that hundreds may play a part. It also finds that girls with autism tend to have many more mutated genes than boys with the disorder, suggesting that it generally takes a larger genomic change to cause autism in girls.

A particularly interesting finding was that, while deletion of a segment of chromosome 7 (specifically, 7q11.23) is associated with Williams Syndrome (marked by hypersocial behavior), duplication of this region is associated with autism.

http://www.nature.com/news/2011/110609/full/news.2011.359.html

http://medicalxpress.com/news/2011-06-genetic-keys-autism.html

http://www.scientificamerican.com/article.cfm?id=autism-genetic-mutations

How common is autism?

Great discussion of why prevalence estimates can be so different, and why diagnosing autism spectrum disorders is so difficult.

http://www.guardian.co.uk/science/blog/2011/jun/07/how-common-autism-diagnosis

Mapping data shows enhanced activity in the 'perception' part of the brain

Brain scans have determined that people with autism concentrate more brain resources in the areas associated with visual detection and identification (temporal, occipital, and parietal lobes), and conversely, have less activity in the areas used to plan and control thoughts and actions (frontal lobe).

http://www.eurekalert.org/pub_releases/2011-04/uom-nre032811.php

An autism brain signature?

May 25, 2011

A genome-wide analysis of the RNA in the brains of individuals with autism has revealed that, while gene expression in the frontal lobe normally varies significantly from that in the temporal lobe due to their different functions, this tended not to be true of autistic brains. Instead, in more than 2/3 autistic individuals, the levels of gene expression between the two lobes were homogenized, as if they had similar functions.
http://www.the-scientist.com/?articles.view/articleNo/29713/title/An-autism-brain-signature-/

New Genetics Work Challenges Basic Ideas about Mental Illness

May 17, 2011

Some background on genetic mutations — explaining single-nucleotide polymorphisms (SNPs), copy-number variants (CNVs), genome-wide association studies (GWAS), and how they’re being used in research into the causes of various disorders.

http://www.scientificamerican.com/article.cfm?id=new-genetics-work-challenges-basic-ideas-about-mental-illness

Researchers link spontaneous gene mutations to autism

May 16, 2011

Preliminary results suggest that as many as % of sporadic autism cases can be explained by spontaneous gene mutations. The findings are also consistent with other studies suggesting that ASDs are more likely in children born to older parents, and in particular, older fathers.

http://medicalxpress.com/news/2011-05-link-spontaneous-gene-mutations-autism.html

Children conceived in winter have a greater risk of autism, study finds

May 5, 2011

An examination of the birth records of children born in California during the 1990s and early 2000s has found a clear link between the month in which a child is conceived and the risk of that child later receiving a diagnosis of autism, with those conceived during winter having a significantly greater risk of autism.

Earlier studies (all much smaller) have found inconsistent results in linking autism risk to month of conception.

http://medicalxpress.com/news/2011-05-children-winter-greater-autism.html

The mirror neuron system in autism: Broken or just slowly developing?

May 3, 2011

It’s been suggested that the mirror neuron system (neurons that activate in similar ways whether we perform actions or watch other people perform the same actions) is broken in autistic individuals, but a new study suggests that it just develops more slowly.

http://medicalxpress.com/news/2011-05-mirror-neuron-autism-broken-slowly.html

An interview with mirror neuron guru Vilayanur S. Ramachandran about autism and mirror neurons.

http://scienceblogs.com/neurophilosophy/2011/03/ramachandran_broken_mirror.php

A world first: The discovery of a common genetic cause of autism and epilepsy

April 8, 2011

Researchers have identified a new gene that predisposes people to both autism and epilepsy. The synapsin gene (SYN1) plays a crucial role in the development of the membrane surrounding neurotransmitters (the synaptic vesicles), affecting communication between neurons.

http://www.physorg.com/news/2011-04-world-discovery-common-genetic-autism.html

Knowing Me, Knowing You: How Social Intuition Goes Awry in Autism

March 7, 2011 

It’s suggested that the social impairment characteristic of autism spectrum disorders may be related to a lack of a type of spindle neurons called Von Economo neurons. These neurons are only found in very social species, such as the great apes, elephants, and whales and ­dolphins, and are found only in the frontoinsular and anterior cingulate cortex.

http://www.scientificamerican.com/article.cfm?id=knowing-me-knowing-you

Cognitive skills in children with autism vary and improve, study finds

September 15, 2010

A three year study looking at how the cognitive skills of children with ASD change over time has found that most of the children (aged 5-6 at the beginning of the study) developed better appreciation of others' thoughts and feelings, and improved ability to plan, regulate, and control their thoughts and actions. However, their ability to construct patterns from wooden blocks and search for shapes hidden in pictures did not improve over time.

www.physorg.com/news203744311.html

Too Much, Too Young: Brain Overgrowth Correlates with the Severity of Autism Symptoms

July 27, 2010

Excess brain growth may be the first sign of autism, starting in the first year of life, if not sooner.

http://www.scientificamerican.com/article.cfm?id=too-much-too-young

Scientists have the genetic causes of autism in their sights

The Autism Genome Project has identified rare genetic mutations (copy number variations (CNVs)), that were 20% more frequent in children with autism than in children without the disorder.

http://www.guardian.co.uk/science/2010/jun/09/autism-study-genetic-causes

http://www.eurekalert.org/pub_releases/2010-06/uoc--wld060710.php

Alternative Biomedical Treatments for Autism: How Good Is the Evidence?

October 7, 2010

Review of alternative autism treatments.

http://www.scientificamerican.com/article.cfm?id=alternative-biomedical-treatments

A Crack in the Mirror Neuron Hypothesis of Autism

May 12, 2010

A new test of mirror neuron activity suggests that autistic individuals’ mirror neurons may behave normally. However, they showed more variable activity in brain regions that process visual images and execute movements. The researchers suggest that it may be faulty signaling, rather than mirror neuron problems, that underlies some of their social difficulties.

The researchers’ tests and interpretations are controversial.

http://news.sciencemag.org/sciencenow/2010/05/a-crack-in-the-mirror-neuron-hyp.html?etoc

Video Q&A: What is autism? - A personal view

http://www.biomedcentral.com/1741-7007/8/42

Stem cells restore cognitive abilities impaired by brain tumor treatment

A rat study has found that transplanted stem cells restored learning and memory to normal levels four months after radiotherapy. This compares with a greater than 50% decline in cognitive function in those rats that didn’t receive the therapy. Cranial irradiation is a common treatment for brain tumors.

[803] Acharya, M. M., Christie L. - A., Lan M. L., Donovan P. J., Cotman C. W., Fike J. R., et al.
(2009).  Rescue of radiation-induced cognitive impairment through cranial transplantation of human embryonic stem cells.
Proceedings of the National Academy of Sciences. 106(45), 19150 - 19155.

http://www.eurekalert.org/pub_releases/2009-11/uoc--scr110509.php

Childhood brain tumors permanently impact cognition & lifestyle

A survey involving 785 CNS cancer survivors, 5,870 survivors of non-CNS cancers (such as leukemia, Hodgkin's disease, and bone tumors), and 379 siblings of CNS cancer survivors, sent at least 16 years after diagnosis, has found that CNS cancer survivors reported significantly greater neurocognitive dysfunction than their siblings and survivors of other types of cancer. Moreover, these problems were linked to lower achievement in education and in full-time employment and income, as well as less chance of being married. The worst problems were found in those who had tumors in the cortex, and those who had cranial radiation treatment.

Ellenberg, L. et al. 2009. Neurocognitive Status in Long-Term Survivors of Childhood CNS Malignancies: A Report From the Childhood Cancer Survivor Study. Neuropsychology, 23 (6), 705-717.

http://www.eurekalert.org/pub_releases/2009-11/apa-bti102709.php

Therapy program has significant effect on autistic toddlers

A randomized controlled trial involving autistic toddlers aged 18 to 30 months has found that those who participated for two years in an intensive program of behavioral therapy known as the Early Start Denver Model improved 17.6 standard score points in IQ, on average, compared with 7 points in the group who received standard community intervention. They were also more likely to be re-diagnosed from autism to pervasive developmental disorder.

[1499] Dawson, G., Rogers S., Munson J., Smith M., Winter J., Greenson J., et al.
(2010).  Randomized, Controlled Trial of an Intervention for Toddlers With Autism: The Early Start Denver Model.
Pediatrics. 125(1), e17-23 - e17-23.

http://www.newscientist.com/article/dn18221-treating-toddlers-for-autism-boosts-iq-later.html

Study finds autistics better at problem-solving

A study involving 15 autistics and 18 non-autistics, aged 14 to 36 and IQ-matched, has found that while both groups completed patterns in a complex problem-solving test (the widely-used Raven's Standard Progressive Matrices) with equal accuracy, the autistics responded significantly faster, and showed a different pattern of brain activity. Specifically, they showed increased activity in extrastriate areas, and decreased activity in the lateral prefrontal cortex and the medial posterior parietal cortex — suggesting visual processing mechanisms may play a more prominent role in reasoning in autistics. The differences between groups did not appear when participants performed a simpler pattern-matching task.

[555] Soulières, I., Dawson M., Samson F., Barbeau E. B., Sahyoun C. P., Strangman G. E., et al.
(2009).  Enhanced visual processing contributes to matrix reasoning in autism.
Human Brain Mapping. 30(12), 4082 - 4107.

http://www.eurekalert.org/pub_releases/2009-06/uom-sfa061609.php

New genes implicated in autism; support new theory of cause

Research involving 104 large Middle Eastern families has implicated half a dozen new genes in autism, and more importantly, strongly supports the emerging idea that autism stems from disruptions in the brain's ability to form new connections in response to experience – consistent with autism's onset during the first year of life, when many of these connections are normally made. Just over 6% of the 88 families with autistic members showed rare, inherited deletions within DNA regions linked to autism. These affected DNA regions varied among families, further indication of autism's large variety of genetic causes. In all, the technique identified five chromosome deletions affecting at least six identifiable genes. Although the genes discovered are diverse in function, all seem to be part of a fundamental network that orchestrates the refinement and maturation of synapses in response to input from the outside world. The network itself is already known to activate at least 300 genes, so it’s no surprise that there are many ways it can be disrupted, explaining why there might be myriad genetic causes of autism, even though in essence it might be all the same problem: a disruption of the brain's ability to modify its synaptic connections in response to experience. The good news is that in all but one case the chromosome deletions didn’t actually remove a gene, they just turned it off — suggesting a possible ‘cure’ if researchers can figure out how to turn them back on.

[942] Hashmi, A., Al-Saad S., Ware J., Joseph R. M., Greenblatt R., Gleason D., et al.
(2008).  Identifying Autism Loci and Genes by Tracing Recent Shared Ancestry.
Science. 321(5886), 218 - 223.

http://www.eurekalert.org/pub_releases/2008-07/chb-mef070808.php

Autism's social struggles due to disrupted communication networks in brain

And a timely imaging study has now provided the clearest evidence to date that synchronization in what might be termed the Theory of Mind network is impaired in autistic people. The Theory of Mind network (which includes the medial frontal gyrus, the anterior paracingulate, and the right temporoparietal junction) is responsible for processing the intentions and thoughts of others. In the study 12 high-functioning autistic adults and 12 controls viewed animated interacting geometric figures, and then asked to select the word from several choices that best described the interaction. The control subjects were consistently better at inferring the intention from the action than the participants with autism were. Brain scans revealed that synchronization between the frontal and posterior regions in the network was reliably lower in the group with autism. The autistic participants' brains also showed much lower activation levels in the frontal regions, and an independent assessment of their Theory of Mind abilities found these reliably correlated with activation in the right temporoparietal junction. The findings point to the need to develop interventions that could target this problem, and also indicate a way to measure an intervention’s effectiveness.

[782] Kana, R. K., Keller T. A., Cherkassky V. L., Minshew N. J., & Just M A.
(2009).  Atypical frontal-posterior synchronization of Theory of Mind regions in autism during mental state attribution.
Social Neuroscience. 4(2), 135 - 152.

http://www.eurekalert.org/pub_releases/2008-07/cmu-ass072308.php

New genetic link to autism identified

Three new studies, using different methods, have all implicated the same gene in the development of autism. The research follows earlier findings implicating a specific region of Chromosome 7 called 7q35. The gene — contactin-associated protein-like 2 (CNTNAP2) — is a gene in this region. The research not only points to this gene predisposing an individual to autism, it also may explain the association with late language onset, a characteristic of most autistic children. The gene was most active in developing brain structures involved in language and thought. The finding may also help explain why autism is so much more common among boys. Statistical evidence for the gene was strongest in families with autistic boys. Less of an association appeared in families with autistic boys and girls, or in families with autistic girls only.

[902] Ledbetter, D. H., Alarcón M., Abrahams B. S., Stone J. L., Duvall J. A., Perederiy J. V., et al.
(2008).  Linkage, Association, and Gene-Expression Analyses Identify CNTNAP2 as an Autism-Susceptibility Gene.
The American Journal of Human Genetics. 82(1), 150 - 159.

[538] Cook Jr., E. H., Arking D. E., Cutler D. J., Brune C. W., Teslovich T. M., West K., et al.
(2008).  A Common Genetic Variant in the Neurexin Superfamily Member CNTNAP2 Increases Familial Risk of Autism.
The American Journal of Human Genetics. 82(1), 160 - 164.

[857] Stillman, A. A., Bakkaloglu B., O'Roak B. J., Louvi A., Gupta A. R., Abelson J. F., et al.
(2008).  Molecular Cytogenetic Analysis and Resequencing of Contactin Associated Protein-Like 2 in Autism Spectrum Disorders.
The American Journal of Human Genetics. 82(1), 165 - 173.

http://www.eurekalert.org/pub_releases/2008-01/uoc--usi010808.php

Autism non-verbal not unintelligent

New findings suggest that the association of autism with low intelligence is a product of their language difficulties. Testing autistic kids and normal kids on two popular IQ tests — the WISC (which relies heavily on language) and Raven's Progressive Matrices (considered the best test of "fluid intelligence", and a test that doesn't require much language) found that while not a single autistic child scored in the "high intelligence" range of the WISC, a third did on the Raven's. A third of the autistics had WISC scores in the mentally retarded range, but only one in 20 scored that low on the Raven's test. The non-autistic children scored similarly on both tests. The same results occurred when the experiment was run on autistic and normal adults.

[580] Dawson, M., Soulières I., Gernsbacher M A., & Mottron L.
(2007).  The level and nature of autistic intelligence.
Psychological Science: A Journal of the American Psychological Society / APS. 18(8), 657 - 662.

http://www.physorg.com/news105376203.html
http://www.eurekalert.org/pub_releases/2007-08/afps-tmo080307.php

Monkeys can reflect on their thoughts

A study involving two rhesus macaque monkeys has shown that a monkey can reflect on its own thoughts and assess its performance. The experiment trained the monkeys to play a video game that tested their ability to remember a particular photograph while also allowing them to make a large or a small bet on how likely they were to be right. The monkeys could also request hints for problems that would otherwise have to be solved by trial and error. Not only did the results provide clear evidence of their ability to engage in metacognition, but the study also points to a means of testing nonverbal humans, such an infants and autistic children.

[1315] Kornell, N., Son L. K., & Terrace H. S.
(2007).  Transfer of metacognitive skills and hint seeking in monkeys.
Psychological Science: A Journal of the American Psychological Society / APS. 18(1), 64 - 71.

http://www.eurekalert.org/pub_releases/2007-04/afps-mat042007.php

Oxytocin may help treat two core autism symptoms

In a pilot study, researchers have found administration of oxytocin has beneficial effects on repetitive behaviors and aspects of social cognition in high-functioning autistic adults.

The research was presented at the American College of Neuropsychopharmacology's Annual Meeting.

http://www.eurekalert.org/pub_releases/2006-12/g-nrs120106.php

A gene for autism

A study has found that those with two copies of a specific variant of a gene within chromosome 7, that regulates production of a protein that influences cell proliferation in various parts of the body, are substantially more likely to be autistic. The link between the MET variant and autism appears primarily in families with two or more affected children. The gene variant is not rare — roughly 47% of the population carry at least one copy of it. It may be that it is affected by prenatal environmental factors or that it interacts with other genes to derail brain formation. It is likely that there are a number of genes associated with autism. But this particular gene variant would explain controversial reports that people with autism often have immune and gastrointestinal problems.

[692] Sacco, R., Persico A. M., Levitt P., Campbell D. B., Sutcliffe J. S., Ebert P. J., et al.
(2006).  A genetic variant that disrupts MET transcription is associated with autism.
Proceedings of the National Academy of Sciences. 103(45), 16834 - 16839.

http://www.sciencenews.org/articles/20061021/fob1.asp

Brain enlargement may be characteristic of autism

Comparison of 164 children with autism and 214 control children (all younger than 3 years) has found significant enlargement in the volume of the cerebral cortex, in both white and grey matter, and generalized throughout the cortex. Head circumference was not significantly different at birth — an increased rate of growth occurred from around 12 months.

[315] Hazlett, H C., Poe M., Gerig G., Smith R G., Provenzale J., Ross A., et al.
(2005).  Magnetic Resonance Imaging and Head Circumference Study of Brain Size in Autism: Birth Through Age 2 Years.
Arch Gen Psychiatry. 62(12), 1366 - 1376.

http://www.eurekalert.org/pub_releases/2005-12/jaaj-bem120105.php

Breakdown of myelin insulation in brain's wiring implicated in childhood developmental disorders

Previous research has suggested that the production of myelin (a fatty insulation coating the brain's internal wiring) is a key component of brain development through childhood and well into middle age, when development peaks and deterioration begins, and that midlife breakdown of myelin is implicated to onset of Alzheimer's disease later in life. Now new research suggests the disruption of myelination is a key neurobiological component behind childhood developmental disorders, such as autism and attention deficit/hyperactivity disorder, and addictive behaviors. The analysis also suggests that alcohol and other drugs of abuse have toxic effects on the myelination process in some adolescents.

Bartzokis, G. 2005. Adolescent Psychiatry. Hillsdale, N.J.: The Analytic Press Inc.

http://www.eurekalert.org/pub_releases/2005-11/uoc--bom111405.php

Why autism is associated with executive function problems

A new imaging study has revealed that autistic boys have less activation in the parts of the brain responsible for executive function (attention, reasoning and problem solving) — specifically, in the caudate nucleus, a critical part of circuits that link the prefrontal cortex of the brain. The researchers have noted similarities in the impairment of specific executive function in children with ADHD and autism.

[2574] Silk, T., Rinehart N., Bradshaw J., Tonge B., Egan G., O’Boyle M., et al.
(Submitted).  Visuospatial Processing and the Function of Prefrontal-Parietal Networks in Autism Spectrum Disorders: A Functional MRI Study.
American Journal of Psychiatry. 163(8), 1440 - 1443.

http://www.eurekalert.org/pub_releases/2005-10/ra-ape102305.php

Finding supports theory that autism results from failure of brain areas to work together

An imaging study indicates people with autism remember letters as geometric shapes, compared to the more usual remembering by their names. Moreover, compared to the control group, the activated brain areas of the people with autism were less likely to work in synchrony (at the same time) while recalling the letters. This supports a theory that autism results from a failure of the various parts of the brain to work together. This theory suggests that therapies emphasizing problem solving skills and other tasks that activate multiple brain areas at the same time might benefit people with autism.

Koshino, H., Carpenter, P.A., Minshew, N.J., Cherkassky, V.L., Keller, T.A. & Just, M.A. 2005. Functional connectivity in an fMRI working memory task in high-functioning autism. NeuroImage, 24 (3), 810-821.

http://www.eurekalert.org/pub_releases/2004-11/nioc-bop112904.php

Special training may help people with autism recognize faces

People with autism tend to activate object-related brain regions when they are viewing unfamiliar faces, rather than a specific face-processing region. They also tend to focus on particular features, such as a mustache or a pair of glasses. However, a new study has found that when people with autism look at a picture of a very familiar face, such as their mother's, their brain activity is similar to that of control subjects – involving the fusiform gyrus, a region in the brain's temporal lobe that is associated with face processing, rather than the inferior temporal gyrus, an area associated with objects. Use of the fusiform gyrus in recognizing faces is a process that starts early with non-autistic people, but does take time to develop (usually complete by age 12). The study indicates that the fusiform gyrus in autistic people does have the potential to function normally, but may need special training to operate properly.

Aylward, E. 2004. Functional MRI studies of face processing in adolescents and adults with autism: Role of experience. Paper presented February 14 at the annual meeting of the American Association for the Advancement of Science in Seattle.

Dawson, G. & Webb, S. 2004. Event related potentials reveal early abnormalities in face processing autism. Paper presented February 14 at the annual meeting of the American Association for the Advancement of Science in Seattle.

http://www.eurekalert.org/pub_releases/2004-02/uow-stm020904.php

Autistic preschoolers don't recognize emotions from facial photographs

Normally developing infants notice their mothers' facial expressions and emotions in the first six months of life and are able to recognize emotions from facial expressions by age 7 months. In a recent study reported at the first International Meeting for Autism Research in San Diego last month, 3- and 4-year-old autistic, developmentally delayed and normally developing children were shown photographs of faces depicting fear and a neutral expression while brain activity was monitored. It was found that the brains of normally developing and developmentally delayed children exhibited different activity depending on the picture being viewed. However, the brain activity of the autistic children remained the same when the different pictures were shown.

Dawson, G. & Dager, S. 2001. Paper presented at the first International Meeting for Autism Research in San Diego in November. The autism meeting was held in conjunction with the annual meeting of the Society for Neuroscience.

http://www.eurekalert.org/pub_releases/2001-12/uow-ahl120401.php

Differences in face perception processing between autistic and normal adults

An imaging study compared activation patterns of adults with autism and normal control subjects during a face perception task. While autistic subjects could perform the face perception task, none of the regions supporting face processing in normals were found to be significantly active in the autistic subjects. Instead, in every autistic patient, faces maximally activated aberrant and individual-specific neural sites (e.g. frontal cortex, primary visual cortex, etc.), which was in contrast to the 100% consistency of maximal activation within the traditional fusiform face area (FFA) for every normal subject. It appears that, as compared with normal individuals, autistic individuals `see' faces utilizing different neural systems, with each patient doing so via a unique neural circuitry.

[704] Pierce, K., Muller R. - A., Ambrose J., Allen G., & Courchesne E.
(2001).  Face processing occurs outside the fusiform `face area' in autism: evidence from functional MRI.
Brain. 124(10), 2059 - 2073.

http://brain.oupjournals.org/cgi/content/abstract/124/10/2059

Autistic 3- and 4-year-olds react to a picture of a familiar toy but not to a picture of their mother

Face recognition is a specialized and highly developed memory system in humans, and a preference for face-like stimuli is evident even in newborn babies. New research has found that, unlike normally developing and even mentally retarded children, autistic 3- and 4-year-olds do not react to a picture of their mother, although they do react when they see a picture of a familiar toy. This highlights that autism is a disorder of the social brain, and may allow diagnoses of autism to be made much earlier than is now possible.

The study was reported at the annual meeting of the Society for Research in Child Development.

http://www.eurekalert.org/pub_releases/2001-04/UoW-Mija-1604101.php

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New screening tool helps identify children at risk

An exam, called the NICU (neonatal intensive care unit) Network Neurobehavioral Scale (NNNS), has been created to identify newborns who may have problems with school readiness and behavior at age four. This opens up the possibility of early intervention to prevent these problems. The screening exam has been tested on 1248 babies, mostly black and on public assistance. Five discrete behavioral profiles were reliably identified; the most extreme negative profile was found in 5.8% of the infants. Infants with poor performance were more likely to have behavior problems at age three, school readiness problems at age four, and low IQ at 4 ½ — 40% had clinically significant problems externalizing (impulsivity and acting out), internalizing (anxiety, depression, withdrawn personalities), and with school readiness (delays in motor, concepts and language skills), and 35% had low IQ.

[596] Liu, J., Bann C., Lester B., Tronick E., Das A., Lagasse L., et al.
(2010).  Neonatal neurobehavior predicts medical and behavioral outcome.
Pediatrics. 125(1), e90-98 - e90-98.

http://www.eurekalert.org/pub_releases/2009-12/bu-nst120709.php

Cognitive dysfunction reversed in mouse model of Down syndrome

Down syndrome is characterized by specific learning impairments (for example, difficulties in using spatial and contextual information to form new memories, but less difficulty at remembering information linked to sensory cues) that point to the hippocampus as a problem area. Investigation has revealed that the problem lies in degeneration of the locus coeruleus, which sends norepinephrine to neurons in the hippocampus. Now a study using genetically engineered mice has found that norepinephrine precursor drugs improved performance in the mice within a few hours. However, the effect did wear off quite quickly too. Other research has looked at acetylcholine, which also acts at the hippocampus. The present findings suggest the best medication regimen will be one that improves both norepinephrine and acetylcholine signals. Locus coeruleus degeneration is also seen in dementia; Alzheimer’s develops among those with Down syndrome at a significantly higher rate than in the general population.

Salehi, A. et al. 2009. Restoration of Norepinephrine-Modulated Contextual Memory in a Mouse Model of Down Syndrome. Science Translational Medicine, 1 (7), 7-17.

http://www.eurekalert.org/pub_releases/2009-11/sumc-nds111309.php
http://www.eurekalert.org/pub_releases/2009-11/uoc--cdr111609.php http://www.the-scientist.com/blog/display/56154/

Testing one time is not enough

A study demonstrating the perils of one-time testing gave 16 common cognitive and neuropsychological tests to groups of people ages 18-39, 50-59 and 60-97 years. The variation between scores on the same test given three times during a two-week period was as big as the variation between the scores of people in different age groups. “It's as if on the same test, someone acted like a 20-year-old on a Monday, a 45-year-old on Friday, and a 32-year-old the following Wednesday”. The study makes clear the dangers of diagnosing learning disability, progressive brain disease or impairment from head injury on the basis of testing on a single occasion. The researcher suggests we should view cognitive abilities as a distribution of many potential levels of performance instead of as one stable short-term level; that people have a range of typical performances, a one-person bell curve. It may also be that within-person variability could be a useful diagnostic marker in itself — for example, extreme fluctuations might be an early warning of mental decline.

[921] Salthouse, T. A.
(2007).  Implications of within-person variability in cognitive and neuropsychological functioning for the interpretation of change.
Neuropsychology. 21(4), 401 - 411.

http://www.physorg.com/news102689828.html
http://www.eurekalert.org/pub_releases/2007-07/apa-csv062507.php

Common cholesterol-lowering drug reverses learning disabilities in mice

Following their discovery that neurofibromatosis 1 (NF1) — the leading genetic cause of learning disabilities — is linked to dysfunction in a protein called Ras, researchers have successfully used a commonly prescribed cholesterol-lowering statin drug (lovastatin) to reverse the learning deficits in mice. Clinical trials with humans are being planned.

[1348] Li, W., Cui Y., Kushner S., Brown R., Jentsch J., Frankland P., et al.
(2005).  The HMG-CoA Reductase Inhibitor Lovastatin Reverses the Learning and Attention Deficits in a Mouse Model of Neurofibromatosis Type 1.
Current Biology. 15(21), 1961 - 1967.

http://www.eurekalert.org/pub_releases/2005-11/uoc--rf110405.php
http://www.newscientist.com/channel/health/dn8276

More light on a common developmental disorder

Chromosome 22q11.2 deletion syndrome is the most common genetic deletion syndrome, and causes symptoms such as heart defects, cleft palate, abnormal immune responses and cognitive impairments. Two related studies have recently cast more light on these cognitive impairments. Previously it was known that numerical abilities were impaired more than verbal skills. The new study found children with the chromosome deletion performed more poorly on experiments designed to test visual attention orienting, enumerating, and judging numerical magnitudes. All three tasks relate to how the children mentally represent objects and the spatial relationships among them, supporting previous arguments that such visual-spatial skills are a fundamental foundation to the later learning of counting and mathematics. The second study found that such children had changes in the shape, size and position of the corpus callosum, the main bridge between the two hemispheres.

[1139] Simon, T. J., Bearden C. E., Mc-Ginn D MD., & Zackai E.
(2005).  Visuospatial and Numerical Cognitive Deficits in Children with Chromosome 22Q11.2 Deletion Syndrome.
Cortex. 41(2), 145 - 155.

[812] Simon, T. J., Ding L., Bish J. P., McDonald-McGinn D. M., Zackai E. H., & Gee J.
(2005).  Volumetric, connective, and morphologic changes in the brains of children with chromosome 22q11.2 deletion syndrome: an integrative study.
NeuroImage. 25(1), 169 - 180.

http://www.eurekalert.org/pub_releases/2005-03/chop-lbt030205.php

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