Intelligence quotient

‘Determination’ can be induced by electrical brain stimulation.

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Applying an electric current to a particular part of the brain makes people feel a sense of determination, say researchers

The men were having a routine procedure to locate regions in their brains that caused epileptic seizures when they felt their heart rates rise, a sense of foreboding, and an overwhelming desire to persevere against a looming hardship.

The remarkable findings could help researchers develop treatments fordepression and other disorders where people are debilitated by a lack of motivation.

One patient said the feeling was like driving a car into a raging storm. When his brain was stimulated, he sensed a shaking in his chest and a surge in his pulse. In six trials, he felt the same sensations time and again.

Comparing the feelings to a frantic drive towards a storm, the patient said: “You’re only halfway there and you have no other way to turn around and go back, you have to keep going forward.”

When asked by doctors to elaborate on whether the feeling was good or bad, he said: “It was more of a positive thing, like push harder, push harder, push harder to try and get through this.”

A second patient had similar feelings when his brain was stimulated in the same region, called the anterior midcingulate cortex (aMCC). He felt worried that something terrible was about to happen, but knew he had to fight and not give up, according to a case study in the journal Neuron.

Both men were having an exploratory procedure to find the focal point in their brains that caused them to suffer epileptic fits. In the procedure, doctors sink fine electrodes deep into different parts of the brain and stimulate them with tiny electrical currents until the patient senses the “aura” that precedes a seizure. Often, seizures can be treated by removing tissue from this part of the brain.

“In the very first patient this was something very unexpected, and we didn’t report it,” said Josef Parvizi at Stanford University in California. But then I was doing functional mapping on the second patient and he suddenly experienced a very similar thing.”

“Its extraordinary that two individuals with very different past experiences respond in a similar way to one or two seconds of very low intensity electricity delivered to the same area of their brain. These patients are normal individuals, they have their IQ, they have their jobs. We are not reporting these findings in sick brains,” Parvizi said.

The men were stimulated with between two and eight milliamps of electrical current, but in tests the doctors administered sham stimulation too. In the sham tests, they told the patients they were about to stimulate the brain, but had switched off the electical supply. In these cases, the men reported no changes to their feelings. The sensation was only induced in a small area of the brain, and vanished when doctors implanted electrodes just five millimetres away.

Parvizi said a crucial follow-up experiment will be to test whether stimulation of the brain region really makes people more determined, or simply creates the sensation of perseverance. If future studies replicate the findings, stimulation of the brain region – perhaps without the need for brain-penetrating electrodes – could be used to help people with severe depression.

The anterior midcingulate cortex seems to be important in helping us select responses and make decisions in light of the feedback we get. Brent Vogt, a neurobiologist at Boston University, said patients with chronic pain and obsessive-compulsive disorder have already been treated by destroying part of the aMCC. “Why not stimulate it? If this would enhance relieving depression, for example, let’s go,” he said.

Social Symptoms In Autistic Children Could Be Caused By Hyper-connected Neurons.

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The brains of children with autism show more connections than the brains of typically developing children do. What’s more, the brains of individuals with the most severe social symptoms are also the most hyper-connected. The findings reported in two independent studies published in the Cell Press journal Cell Reports on November 7th are challenge the prevailing notion in the field that autistic brains are lacking in neural connections.

The findings could lead to new treatment strategies and new ways to detect autism early, the researchers say. Autism spectrum disorder is a neurodevelopmental condition affecting nearly 1 in 88 children.

“Our study addresses one of the hottest open questions in autism research,” said Kaustubh Supekar of Stanford University School of Medicine of his and his colleague Vinod Menon’s study aimed at characterizing whole-brain connectivity in children. “Using one of the largest and most heterogeneous pediatric functional neuroimaging datasets to date, we demonstrate that the brains of children with autism are hyper-connected in ways that are related to the severity of social impairment exhibited by these children.”

In the second Cell Reports study, Ralph-Axel Müller and colleagues at San Diego State University focused specifically on neighboring brain regions to find an atypical increase in connections in adolescents with a diagnosis of autism spectrum disorder. That over-connection, which his team observed particularly in the regions of the brain that control vision, was also linked to symptom severity.

“Our findings support the special status of the visual system in children with heavier symptom load,” Müller said, noting that all of the participants in his study were considered “high-functioning” with IQs above 70. He says measures of local connectivity in the cortex might be used as an aid to diagnosis, which today is based purely on behavioral criteria.

For Supekar and Menon, these new views of the autistic brain raise the intriguing possibility that epilepsy drugs might be used to treat autism.

“Our findings suggest that the imbalance of excitation and inhibition in the local brain circuits could engender cognitive and behavioral deficits observed in autism,” Menon said. That imbalance is a hallmark of epilepsy as well, which might explain why children with autism so often suffer with epilepsy too.

“Drawing from these observations, it might not be too far fetched to speculate that the existing drugs used to treat epilepsy may be potentially useful in treating autism,” Supekar said.

Does Breastfeeding Help Prevent ADHD?

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ADHD is thought to be hereditary; that means that it is passed from parent to child through genes. It would seem, therefore, that there wouldn’t be any way to prevent or reduce the chances that your child may develop ADHD. However, some studies show that breastfeeding may help prevent ADHD.

Breastfeeding provides optimal nutrition for babies – containing vitamins, protein and fat. It is more easily digested and contains antibodies to help fight viruses and infection. Children who are breastfed are less likely to develop allergies and asthma. They have fewer ear infections and respiratory illnesses than those fed with formula. It may lower the risk of diabetes, obesity and some forms of cancer. It has also been linked to higher IQs.

In 2005, a study completed in Poland compared children between the ages of 4 and 11 years old with ADHD to children without ADHD.  Researchers found that children with ADHD were breastfed for shorter durations that those without ADHD. The study concluded “The short duration of breastfeeding as environmental factor may be considered a risk factor of ADHD symptoms.” [1] The scientists noted that further research was needed, however, to form firm conclusions about any link between not breastfeeding, or breastfeeding for shorter amounts of time, and ADHD.

This year (2013), two more studies were conducted:

  • A study completed in Israel compared three different groups of children: 56 children with ADHD, 52 siblings without ADHD and 51 non-related children without ADHD. At three months, only 43 percent of the children with ADHD were breastfed. The other two groups were much higher: 69 percent for the siblings and 73 percent for the non-related group. At six months old, only 29 percent of those with ADHD were still being breast fed, while 50 percent of the siblings and 57 percent of the non-related children were still being breastfed.
  • A second study, completed at the Steven and Alexandra Cohen Children’s Medical Center of New York found similar results. There study compared 54 preschoolers with ADHD to 54 preschoolers without ADHD. Researchers found that over one-half of children with ADHD were breastfed for one month or less while only one-fourth of the control group was breastfed for that short of a time. More than twice as many children without ADHD were breastfed for more than six months; 46 percent of non-ADHD children compared to only 22 percent of those with ADHD.

What the Studies Say

 Without a doubt, all the studies showed that on average, children with ADHD were breastfed for shorter durations that those without ADHD. Scientists just aren’t sure what this means yet. Is it possible that breast milk has some properties that protect children against developing ADHD?

Dr. Andrew Adesman, the lead author of the study completed in New York, speculates that it may be the fatty acids in breast milk that help prevent ADHD. Other studies have shown that using omega 3 fatty acids have helped to reduce some symptoms of ADHD. It is possible then, that children receiving fatty acids from birth on, through breast milk, are given some type of ability to fend off ADHD symptoms.

First Children Are Smarter—but Why?

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One mysterious finding—and seven theories.

Those born earlier perform better in school”—and according to a new study, it’s because of the parents.

Moms and dads simply go easy on their later-born kids, according to data analyzed by economists V. Joseph Hotz and Juan Pantano, and as a result, first-born children tend to receive both the best parenting and the best grades.

The first thing to say about a study like this is that lots of readers will reflexively disagree with the assumption. With kids, as with anything, shouldn’t practice make perfect? Don’t parents get richer into their 30s and 30s, providing for better child-rearing resources? I’m a first child, myself, well-known within the family for being unorganized, forgetful, periodically disheveled, and persistently caught day-dreaming in the middle of conversations. For this reason, I’ve put stock in what you might call the First Pancake Theory of Parenting. In short: First pancakes tend to come out a little funny, and, well, so did I. And so do many first-borns.

But international surveys of birth orders and behavior (which might have offered me an empirical excuse to behave this way) aren’t doing me any favors. First borns around the world, it turns out, have higher IQs, perform better in school, and are considered more accomplished by their parents. Looking at parent evaluations of children from the National Longitudinal Survey of Youth in 1979, the researchers found that mothers are much more likely to see their first children as high-achievers. They regard their subsequent children as considerably more average in their class (see table and chart below).

Let’s briefly count off and nickname some of the leading older-kids-are-smarter theories reviewed by the economists, which push back against the principle of first pancakes.

1) The Divided-Attention Theory: Earlier-born siblings enjoy more time, care and attention than later-born siblings because attention is divided between fewer kids.

2) The Bad-Genes Theory: The strong evidence of higher IQs among first children leads some to believe that later kids are receiving diminished “genetic endowment.”

3) The I’ve-Had-It-With-Kids! Theory: Some parents decide to stop having more children after a difficult experience raising one. In that case, the poorer performance of later children isn’t genetic, so much as selection bias: Some parents keep having children until they have one that’s so problematic it makes them say “enough.”

4) The No-One-to-Teach Theory: This is the idea that older siblings benefit from the ability to teach their younger brothers and sisters. Building these teaching skills helps them build learning skills that makes them better in school.

5) The Divorce Theory: Family crises like divorce are far more likely to happen after the first child in born (first marriage, then divorce, then a first child is not a common sequence) and they can disrupt later kids’ upbringing.

6) The Lazy-Parent Theory: The general idea here is that first-time parents, scared of messing up their new human, commit to memory the first chapter of Battle Hymn of the Tiger Mother but by the second or third child, they’ve majorly chilled out.

Hotz and Pantano settle close to Theory (6). Parents are more likely to make strict rules (about, e.g., TV-watching) and be intimately involved in the academic performance of their first children, according to survey data. They’re also more likely to punish their first child’s bad grades. Hotz and Pantano say moms and dads start tough and go soft to establish a “reputation” within their household for being strict—a reputation they hope will trickle down to the younger siblings who will be too respectful to misbehave later on.

The theory is interesting but not entirely persuasive. First it seems nearly-impossible to test. The survey data is much better at showing that parents chill out as they have more kids than at showing that parents chill out *because* they’re explicitly establishing a reputation for strictness. Nothing in the paper seems to argue against the simpler idea that parents seem to go soft on later kids because raising four children with the same level of attention you’d afford a single child is utterly exhausting. What’s more, if later-born children turn out to be less academically capable than their older simblings, it suggests that the economists’ reputation theory is failing in families across the country.

The Relation Between Intelligence and Religiosity.

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A Meta-Analysis and Some Proposed Explanations

A meta-analysis of 63 studies showed a significant negative association between intelligence and religiosity. The association was stronger for college students and the general population than for participants younger than college age; it was also stronger for religious beliefs than religious behavior. For college students and the general population, means of weighted and unweighted correlations between intelligence and the strength of religious beliefs ranged from −.20 to −.25 (mean r = −.24). Three possible interpretations were discussed. First, intelligent people are less likely to conform and, thus, are more likely to resist religious dogma. Second, intelligent people tend to adopt an analytic (as opposed to intuitive) thinking style, which has been shown to undermine religious beliefs. Third, several functions of religiosity, including compensatory control, self-regulation, self-enhancement, and secure attachment, are also conferred by intelligence. Intelligent people may therefore have less need for religious beliefs and practices.

  • Source: SAGE

 

Unique Brain Pattern May Explain Superior Math Skills in Autism.

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A unique pattern of brain organization may explain why children with autism spectrum disorder (ASD) often possess superior math skills.

A small brain imaging study showed that children between the ages of 7 and 12 years with ASD had significantly superior numerical problem-solving abilities, including the use of more sophisticated strategies to figure out single-digit addition questions, than their age-, sex-, and IQ-matched healthy peers.

In addition, participants with ASD showed different activation patterns in the ventral temporal-occipital cortex (VTOC), the posterior parietal cortex, and the medial temporal lobe during mathematical problem solving — with activation patterns in the VTOC region actually predicting these superior abilities.

“Our findings suggest that altered patterns of brain organization in areas typically devoted to face processing may underlie the ability of children with autism to develop specialized skills,” lead author Teresa Iuculano, PhD, from the Department of Psychiatry and Behavioral Sciences at Stanford University School of Medicine, in California, and from the Stanford Cognitive and Systems Neuroscience Laboratory, said in a release.

She told Medscape Medical News that because children with ASD are often bad at recognizing faces, this particular area was recruited instead for math abilities in this patient population.

“However, this isn’t a universal finding, and we know that the spectrum is very broad. So there could be many different talents discovered, including music and drawing, and should be assessed on a case-by-case basis,” said Dr. Iuculano.

“If a parent sees that a child is strongly interested in something, they should help them to follow their passion. This is important for all children, but especially those with autism. It can be used as a relaxation tool and to help them to enjoy life more.”

The study was published online August 19 in Biological Psychiatry.

Mostly Anecdotal Evidence

The investigators note that although past research has suggested that individuals with ASD often have high mathematical skills, the evidence has been “mostly anecdotal and descriptive.”

For the current study, they sought to assess both the cognitive and neural characterizations of these skills.

“We thought that because math is such a concrete discipline, and with many rules, it could represent a good way to look at superiorities in a group of children on the spectrum,” said Dr. Iuculano.

The researchers enrolled 18 children with ASD (78% boys) and 18 children without the disorder, who were considered the “control group” (also 78% boys).

Standardized tests given during the study’s recruitment stage showed that all of the participants had IQs considered to be in the normal range; and those with ASD had “normal” verbal and reading skills. Standardized math tests were also administered.

While undergoing functional magnetic resonance imaging (fMRI) scans, all children were asked to solve addition problems, one at a time.

During the scans, the researchers also interviewed the participants to determine which of the following types of problem-solving strategies were being used: remembering an answer already known (retrieval), counting on fingers or in their heads, or decomposition.

The latter strategy is a comparatively sophisticated method and consists of breaking down a problem into several components.

Significant Differences

Results showed that the group with ASD had significantly higher scores on the numerical operations subscale of the Weschsler Individual Achievement Test–Second Edition for mathematics (WIAT-II) than the control group (P= .012).

They also displayed significantly greater use of decomposition (P = .033), “suggesting that more analytic strategies, rather than rote memory, were the source of their enhanced abilities,” the investigators note.

There were no between-group differences in use of counting or retrieval strategies or on any of the 4 working memory measures assessed.

The MRI scans showed “several cortical regions where arithmetic complexity-related activity patterns differed significantly” between the 2 groups.

“Notably, high cross-validation classification accuracies (80% to 90%) were in [VTOC], including bilateral inferior lateral occipital cortex and fusiform gyrus, as well as posterior parietal cortex, including the left intraparietal sulcus, angular gyrus, and the left precuneus,” write the researchers.

Significant differences in activity patterns were also found in medial temporal lobe regions.

Finally, “numerical abilities in the ASD group were predicted by the pattern of neural activity in an area of the left VTOC encompassing the left fusiform gyrus and lateral occipital cortex,” whereas numerical abilities in the control group were predicted by activity patterns in the left dorsolateral prefrontal cortex.

Not Universal

Overall, “there appears to be a unique pattern of brain organization that underlies superior problem-solving abilities in children with autism,” senior author Vinod Menon, PhD, professor of psychiatry and behavioral sciences at Stanford and from the Child Health Research Institute at the Lucile Packard Children’s Hospital, said in a release.

He added that although instant recall of calendar dates (a skill often found in individuals with ASD) is not likely to help with academic and professional success, “developing good mathematical skills could make a big difference in the life of a child with autism,” including possibly leading to future employment.

“Our study supports the idea that the typical brain development in autism can lead not just to deficits but also to some remarkable cognitive strengths. We think this can be reassuring to parents,” said Dr. Menon.

However, he noted that it is important to realize that not all children with ASD have superior math skills. So future research should examine the neural basis of variations in problem-solving abilities.

Dr. Iuculano added that she is excited about the current study’s findings on both research and clinical levels.

“As a scientist, it’s great that we’re understanding how the brain works in children with autism. And on a practical level, it’s important because it can raise awareness of the fact that these individuals can be contributing in a very good way to society,” she said.

Not Limited to Math

“I think this is not new as such, but it’s a very good study and important because it extends some things we already know,” Laurent Mottron, MD, PhD, professor of psychiatry at the University of Montreal, Quebec, Canada, and scientific director of the University’s Center of Excellence in Pervasive Development Disorders, toldMedscape Medical News.

He added that mathematic cognition has not been really studied before in ASD; but the take-away message is not that these findings are specific only to mathematics.

“This overactivation of the occipital region, and specifically the fusiform gyrus, is found in all tasks involving any visual information,” said Dr. Mottron, who was not involved with this research.

As reported at the time by Medscape Medical News, his investigative team published findings from a meta-analysis in Human Brain Mapping 2 years ago. Their analysis of 26 fMRI studies and more than 700 individuals showed that those with ASD had higher activity in the temporal and occipital regions in relation to visual-based tasks than those without the disorder.

“As scientists, we are happy when something is replicated. Here it’s more than replication, it’s specification. But I think if you want to see the big picture, you need to realize this isn’t only related to mathematics. Because autistics, when reasoning in general, use more of their perceptual expertise than other people,” he said.

“And I’m quite happy that now it’s become a kind of consensual message about autistic intelligence.”

Source: Medscape.com

 

Gestational hypothyroxinemia associated with autism occurrence.

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Children born to mothers who had severe, early gestational hypothyroxinemia are nearly four times more likely to have autism, according to researchers. Although their results do not demonstrate causality, researchers said they lend support to the connection between low thyroid function and a child’s developing brain.

“It is increasingly apparent to us that autism is caused by environmental factors in most cases, not by genetics,” Gustavo C. Román, MD, neurologist at Houston Methodist Hospital, said in a press release. “That gives me hope that prevention is possible.”

The researchers used data from the Generation R Study to examine the relationship between thyroid function tests at 6 to 24 weeks of gestation in 5,100 women and parent-reported autistic symptoms in children aged 6 years. Autistic symptoms were measured by the Pervasive Development Problems (PDP) subscale (>98th percentile) and the Social Responsiveness Scale (SRS; the top 5%), according to researchers. Eighty children were defined as a “probable autistic child,” according to these scores.

Data indicate children born to mothers with early gestational hypothyroxinemia were four times more likely to have autism (adjusted OR=3.89; 95% CI, 1.83-8.20). However, no associations were made between maternal thyroid-stimulating hormone and free thyroxine during early pregnancy and children’s borderline and clinical PDP scores, the researchers wrote.

Children aged 6 years were twice as likely to demonstrate borderline PDP scores when their mothers had severe maternal hypothyroxinemia during early gestation (adjusted OR=2.02; 95% CI, 1.16-3.51), researchers added.

Furthermore, children of hypothyroxinemic mothers displayed higher odds for developing clinical PDP scores by age 6 years (adjusted OR=2.60; 95% CI, 1.30-5.18), according to data. No sex differences were observed.

“The next steps are interventional studies,” Román said. “We must look at a large nationwide population of women in early pregnancy to measure urine iodine and thyroid function. We must then correct thyroid deficiencies, if present, and provide prenatal vitamins with supplementary iodine. If autism cases fall precipitously compared with recent historical numbers, I think we will be able to conclude that thyroid function is critical.”

Disclosure: One of the researchers reports being remunerated contributing editor of the Achenbach System of Empirically Based Assessment.

PERSPECTIVE

 

  • This study’s findings, that severe hypothyroxinemia (maternal free T4 in the lowest 5th percentile with normal serum TSH) was associated with an almost fourfold increased risk for probable autism, add to the growing body of observational studies demonstrating that even mild maternal thyroid hypofunction in pregnancy is associated with adverse effects on child neurodevelopment. Dietary iodine deficiency is one potential cause of maternal hypothyroxinemia, but urinary iodine concentrations were not assessed in this study. The Controlled Antenatal Thyroid Screening (CATS) study is the only clinical trial to date to assess the effects of levothyroxine treatment for hypothyroxinemic pregnant women on child development; the CATS study found no effect of treatment on IQ at age 3 years. Prospective interventional studies are needed to better understand whether screening for and treatment of mild maternal thyroid hypofunction will improve IQ as well as risk for autism and attention deficit disorders.
  • Elizabeth N. Pearce, MD
  • Associate professor of medicine Boston University School of Medicine

Source: Endocrine Today

 

AI scores same as a 4-year-old in verbal IQ test.

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Computers aren’t really known for their way with words, but that could be about to change. An artificial intelligence program recently scored as high as a 4-year-old on a test of verbal IQ. The result may help AIs develop common sense.

AIs such as Google’s search engine or IBM’s Watson typically perform well in specific areas, like ranking web pages or answering game-show style questions. But these systems tend to fail when asked to do things outside of their narrow area of expertise. For years researchers have attempted to build systems with a more general “common sense” understanding, but have had mixed results.

iq

Step forward ConceptNet. Developed by Catherine Havasi and her team at the MIT Media Lab ConceptNet draws upon a crowdsourced database of millions of statements describing simple relationships between everyday objects, such as “a fawn is a deer” or “ice cream is capable of melting”.

Havasi describes the system as containing “the kind of information that everybody knows about the world but that nobody ever writes down because we learn it too early”.

To test ConceptNet’s overall intelligence, Robert Sloan and Stellan Ohlsson of the University of Illinois at Chicago, who were not involved in the system’s creation, used a standard measure of child IQ called the Wechsler Preschool and Primary Scale of Intelligence. The verbal portion of the test asks questions in five categories, ranging from simple vocabulary questions, like “What is a house?”, to guessing an object from a number of clues such as “You can see through it. It is a square and can be opened. What is it?”

To answer a question from the test, like “What do you wear on your head?”, ConceptNet searches its database for the object that is most closely related to the pair “wear” and “head”.

For the three main categories of questions – information, vocabulary and word reasoning – Sloan and Ohlsson found that the system’s aggregate verbal IQ was equal to that of an average human 4-year-old. “I didn’t expect to see 4-year-old performance,” says Sloan, who presented the results at the Association for the Advancement of Artificial Intelligence conference in Bellevue, Washington, last week. Havasi points out that this research only tested the system’s verbal ability and ignored parts of the test that covered spatial and symbolic reasoning.

She speculates that the latest version of ConceptNet, which has 17 million statements instead of the million available to the version tested, might score even higher. Sloan thinks that with better algorithms, ConceptNet could score as high as a 5 or 6-year-old.

Source: http://www.newscientist.com

 

Iodine deficiencies during pregnancy linked to lower IQ in offspring.

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Iodine deficiencies during pregnancy may have negative neurocognitive outcomes among offspring, according to findings by researchers in the United Kingdom that were published in The Lancet.

“Pregnant women and those planning a pregnancy should ensure adequate iodine intake; good dietary sources are milk, dairy products and fish. Women who avoid these foods and are seeking alternative iodine sources can consult the iodine fact sheet that we have developed, which is available on the websites of the University of Surrey and the British Dietetic Association. Kelp supplements should be avoided, as they may have excessive levels of iodine,” Sarah C. Bath, PhD, RD, of the department of nutritional sciences at the University of Surrey, said in a press release.

Bath and colleagues analyzed stored samples of urinary iodine concentrations from 1,040 first-trimester pregnant women, measures of IQ from the offspring aged 8 years and reading ability at age 9 years. The mother-child pairs were collected from the Avon Longitudinal Study of Parents and Children (ALSPAC).

The researchers defined mild-to-moderate iodine deficiency as a median urinary iodine concentration of 91.1 mcg/L (interquartile range [IQR], 53.8-143; iodine-to-creatinine ratio of 110 mcg/g; IQR, 74-170).

After adjusting for 21 socioeconomic, parental and child factors as confounders, data indicated that children of women with an iodine-to-creatinine ratio of less than 150 mcg/g were more likely to have scores in the lowest quartile for verbal IQ (OR=1.58; 95% CI, 1.09-2.3), reading accuracy (OR=1.69; 95% CI, 1.15-2.49) and reading comprehension (OR=1.54; 95% CI, 1.06-2.23) vs. those of mothers with ratios of at least 150 mcg/g. Furthermore, scores continued to dwindle when the less than 150-mcg/g group was subdivided, researchers wrote.

In an accompanying commentary, Alex Stagnaro-Green, MD, MHPE,professor of medicine and obstetrics and gynecology at the George Washington University School of Medicine and Health Sciences, andElizabeth N. Pearce, MD, associate professor of medicine at Boston University School of Medicine, wrote that this study, along with previous research, represents a call-to-action because of the documented link between iodine deficiency and poor neurocognitive outcomes.

 “Absence of a public health policy in the face of clear documentation of moderate iodine deficiency and strong evidence of its deleterious effect on the neurodevelopmentof children is ill advised,” they wrote. “Nor should unmonitored and adventitious dietary iodine sources continue to be relied on.”

Source: Endocrine Today

Effect of inadequate iodine status in UK pregnant women on cognitive outcomes in their children: results from the Avon Longitudinal Study of Parents and Children (ALSPAC)

Summary

Background

As a component of thyroid hormones, iodine is essential for fetal brain development. Although the UK has long been considered iodine replete, increasing evidence suggests that it might now be mildly iodine deficient. We assessed whether mild iodine deficiency during early pregnancy was associated with an adverse effect on child cognitive development.

Methods

We analysed mother—child pairs from the Avon Longitudinal Study of Parents and Children (ALSPAC) cohort by measuring urinary iodine concentration (and creatinine to correct for urine volume) in stored samples from 1040 first-trimester pregnant women. We selected women on the basis of a singleton pregnancy and availability of both a urine sample from the first trimester (defined as ≤13 weeks’ gestation; median 10 weeks [IQR 9—12]) and a measure of intelligence quotient (IQ) in the offspring at age 8 years. Women’s results for iodine-to-creatinine ratio were dichotomised to less than 150 μg/g or 150 μg/g or more on the basis of WHO criteria for iodine deficiency or sufficiency in pregnancy. We assessed the association between maternal iodine status and child IQ at age 8 years and reading ability at age 9 years. We included 21 socioeconomic, parental, and child factors as confounders.

Findings

The group was classified as having mild-to-moderate iodine deficiency on the basis of a median urinary iodine concentration of 91·1 μg/L (IQR 53·8—143; iodine-to-creatinine ratio 110 μg/g, IQR 74—170). After adjustment for confounders, children of women with an iodine-to-creatinine ratio of less than 150 μg/g were more likely to have scores in the lowest quartile for verbal IQ (odds ratio 1·58, 95% CI 1·09—2·30; p=0·02), reading accuracy (1·69, 1·15—2·49; p=0·007), and reading comprehension (1·54, 1·06—2·23; p=0·02) than were those of mothers with ratios of 150 μg/g or more. When the less than 150 μg/g group was subdivided, scores worsened ongoing from 150 μg/g or more, to 50—150 μg/g, to less than 50 μg/g.

Interpretation

Our results show the importance of adequate iodine status during early gestation and emphasise the risk that iodine deficiency can pose to the developing infant, even in a country classified as only mildly iodine deficient. Iodine deficiency in pregnant women in the UK should be treated as an important public health issue that needs attention.

Source: Lancet

 

 

Intelligence linked to ability to ignore distractions.

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People with higher IQs are slow to detect large background movements because their brains filter out non-essential information, say US researchers.

Instead, they are good at detecting small moving objects.

The findings come in a study of 53 people given a simple, visual test inCurrent Biology.

The results could help scientists understand what makes a brain more efficient and more intelligent.

Continue reading the main story

“Start Quote

We expected that all participants would be worse at detecting the movement of large images, but high IQ individuals were much, much worse…”

Michael MelnickUniversity of Rochester

In the study, individuals watched short video clips of black and white bars moving across a computer screen. Some clips were small and filled only the centre of the screen, while others filled the whole screen.

The participants’ sole task was to identify in which direction the bars were drifting – to the right or to the left.

Participants also took a standardised intelligence test.

The results showed that people with higher IQ scores were faster at noticing the movement of the bars when observing the smallest image – but they were slower at detecting movement in the larger images.

Michael Melnick of the University of Rochester, who was part of the research team said the results were very clear.

“From previous research, we expected that all participants would be worse at detecting the movement of large images, but high IQ individuals were much, much worse.

The authors explain that in most scenarios, background movement is less important than small moving objects in the foreground, for example driving a car, walking down a hall or moving your eyes across the room.

People with higher IQs appear to be able to concentrate better

As a person’s IQ increases, so too does his or her ability to filter out distracting background motion and concentrate on the foreground.

In an initial study on 12 people, there was a 64% correlation between motion suppression and IQ scores. In this larger study on 53 people, a 71% correlation was found.

In contrast, previous research on the link between intelligence and reaction times, colour discrimination and sensitivity to pitch found only a 20-40% correlation.

But the ability to ignore background movements is not the only indicator of intelligence.

“Because intelligence is such a broad construct, you can’t really track it back to one part of the brain,” says Duje Tadin, who also worked on the study.

“But since this task is so simple and so closely linked to IQ, it may give us clues about what makes a brain more efficient, and, consequently, more intelligent.

“We know from prior research which parts of the brain are involved in visual suppression of background motion.

“This new link to intelligence provides a good target for looking at what is different about the neural processing, what’s different about the neurochemistry, what’s different about the neurotransmitters of people with different IQs.”

Source: BBC