Author Archives: Tara Haelle

Tara Haelle

About Tara Haelle

Tara Haelle, health editor of DoubleXScience, is a photographer, former high school teacher, current adjunct journalism professor (Bradley University), aspiring children’s book writer, avid scuba diver, former triathlete, sometimes yogi, and eternally curious journalist who primarily specializes in health and science reporting. She was once a world traveler, eating strange insects, climbing ancient ruins and swimming with sharks, but that was before she became a mom (though she knows those days beckon again soon). She also blogs about health and science for parents at Red Wine & Apple Sauce and is a senior editor of mental health at dailyRx News. She is most passionate about reporting on vaccines, marine biology, mental health, parenting and prenatal and children’s health, but she also dreams of a day when she can revamp the entire U.S. educational system to improve reading instruction and science literacy.

Sesame Street helps unlock the secrets to the brain during children’s learning

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By Tara Haelle, Health Editor
[This post appeared previously at Red Wine and Apple Sauce.]

Looking to let go of a little “mommy guilt” for using the television now and then to give yourself a breather? There may be plenty of evidence that leaving children to watch too much television is a bad idea, but there is something to the idea that educational TV is, well, educational. We have the brain scans to prove it!

A study published in PLOS Biology used functional MRI scans to check out the brains of 26 children and 20 adults while they watched 20 minutes of Sesame Street. The actual purpose of the study wasn’t to find out if Sesame Street was educational per se. Rather, it was to observe the neural processes in the brain while a child is learning “naturalistically” and then see whether what they saw could predict how well the children would perform on standardized IQ tests.

Often, participants in studies receive fMRI scans while they are doing some sort of task that is supposed to simulate learning and/or stimulate certain neural processes. For example, a study subject might be asked to put together a three-dimensional puzzle on a computer (so their head remains still enough for the scan) to see how the brain interprets spatial relations.

However, these sorts of oversimplified “lab” tasks are not always representative of real-world activities, so it’s not clear whether what the researchers see on the brain images during these tasks is necessarily indicative of what REAL-life spatial relations thinking looks like. Are the neural processes seen in an fMRI scan while putting together blocks on a computer screen the same as what’s seen in the brain while a person builds a treehouse?

In this study, the researchers found a partial answer to exactly that kind of question, and the answer is no.

The children in study, ranging in age from 4 to 11 and all typically developing, watched the same 20-minute montage of short clips with Big Bird, Cookie Monster, the Count, Oscar and the rest of the gang teaching numbers and letters, shapes and colors, planets and countries, and so on. Meanwhile, the fMRI was taking a snapshot of their brain every two seconds.

The fMRI (which uses a giant magnet, not radiation, to peek into the brain) works by dividing the brain into a 3-D grid so that it can measure the intensity of the brain signals in each little section (about 40,000 of them, called voxels). The researchers collected a total of 609 images of each participant’s brain, which they could then use to map out the neural processes of the participants while they were watching.

They also had the children (23 of them), in a separate fMRI scanning period, perform a one of those lab-only fMRI tasks. In this case, the kids matched isolated pairs of faces, numbers, words and shapes on the computer (they pressed a button if the two images shown matched) while the fMRI images of their brains were created.

Finally, the children (19 of them) took IQ tests that primarily tested their math and verbal skills. Then the researchers analyzed the maps of neural processes in the children and their comparisons with the adults.

They found a couple of interesting things. First, the kids whose neural “maps” were most similar to the adults also performed the best on the IQ tests. This means kids’ brain structure matures in a predictable way, which the researchers called “neural maturity.”

“Broadly speaking, the children showed group-level similarity to adults in cortical regions associated with vision (occipital cortex), auditory processing (lateral temporal cortex), language (frontal and temporal cortex), visuo-spatial processing and calculation (intraparietal cortex), and several other functions,” the authors wrote.

The fMRI scan on the left represents correlations in neural activity between children and adults, in the middle between children and other children, and on the right between adults and other adults. Such neural maps, says University of Rochester cognitive scientist Jessica Cantlon, reveal how the brain’€™s neural structure develops along predictable pathways as we mature.

Second, the brain maps created during the Sesame Street viewing accurately predicted how the children performed on the IQ tests. Kids who did better on the verbal tasks showed more mature neural patterns in a part of the brain that handles speech and language, called the Broca area. Meanwhile, the kids whose math scores were highest had more neural maturity in a part of the brain that processes numbers, called intraparietal sulcus.

But the researchers’ other finding was that those areas of neural maturity seen during Sesame Street viewing — the ones that matched up with the children’s scores on the IQ test — were not seen during the fMRI task of matching faces, numbers, words and shapes. Basically, the “let’s try to simulate what learning looks like in the brain” task designed specifically for fMRI scans didn’t help much. But the more naturalistic, organic learning that takes places while watching Sesame Street did work.

Researchers now know they can use activities like viewing educational TV to scan children’s brains and learn more about how they learn — and it’s more accurate and helpful than invented computer tasks. It’s possible this technology and research could be applied to understanding better what’s going on with certain learning disabilities.

But a nice additional finding is that, hey, Sesame Street really IS educational! Of course, my son’s favorite show is a different PBS production — Dinosaur Train (which I admit I enjoy too) — so I also feel a better that little D spends a half hour or two, several days a week, learning from Buddy the Tyrannosaurus Rex, Tiny the Pteranodon, Mr. Conductor and Dr. Scott the Paleontologist about dinosaurs, carnivores, herbivores and how to test a hypothesis. All aboard!

Why a UN ban on thimerosal in vaccines would be a big mistake

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By Tara Haelle, Health Editor

[This post appeared previously at Red Wine and Apple Sauce.]

Several articles published in Pediatrics today discuss an issue that could affect the protection of children everywhere from vaccine-preventable diseases. The posts center on a controversy that keeps coming up related to vaccines – the use of thimerosal in them.

All three Pediatrics articles deal with the same thing: an international treaty drafted by the United Nation Environmental Program’s Global Mercury Partnership to reduce mercury pollution and environmental mercury exposure across the world. Great! This is an important and valuable initiative – except for one part. As part of the treaty, the UN wants to ban the use of thimerosal, a mercury-containing preservative, used in vaccines. Not so good. The short version for why? This proposed ban threatens millions of children’s lives across the world, including children in the U.S. and in other developed countries. I’ll get to the long version in a moment.

First, the World Health Organization and American Academy of Pediatricians (AAP) have already pushed for the thimerosal ban provision to be removed from the UN treaty. But today’s three AAP articles drive the point home. One of these provides some historical context for why thimerosal was removed from childhood vaccines in the U.S. (as recommended by the AAP and the U.S. Public Health Services in 1999) and in other high-income countries. The other two emphasize just how important it is – and how ethically essential it is –that the ban not be included in the UN treaty.

Here’s the back story:
A 1997 US FDA review of the mercury content in products revealed that the amount of thimerosal in childhood vaccines could, possibly theoretically, build up to exceed the EPA’s guidelines (but not the FDA’s guidelines or those of the Agency for Toxic Substances Disease Registry) on safe exposure limits for inorganic mercury, called methylmercury.

Methylmercury is the neurotoxin you hear about when you’re warned not to eat too much fish ( especially while pregnant). Back in 1999, scientists knew a lot about methylmercury, but they didn’t know much about ethylmercury, the type in thimerosal. As Dr. Louis Cooper and Dr. Samuel Katz, both involved with the 1999 recommendations, put it, “the absence of clear data for ethylmercury did not allow any assumption to be made about its safety.”

Meanwhile, debates were raging in Congress about concerns over vaccines and autism, fueled by the now-retracted and thoroughly debunked (pdf) study by Andrew Wakefield linking the MMR vaccine to autism. Parents were scared and confused. Media coverage was exacerbating the impression that public health officials weren’t being forthright about vaccine risks.

So, poof! All thimerosal was pulled from childhood vaccines except the multi-dose flu vaccine, since kids getting that would only get amounts below the EPA guidelines for methylmercury (even though, again, thimerosal is ETHYLmercury).

Now fast forward to today. We know a LOT more about ethylmercury: namely, that it’s not as bad as methylmercury and sails through our bodies a lot more quickly. In fact, methylmercury’s half-life is about seven times that of ethylmercury, which does not build up in the body like methylmercury does.
“There is no credible scientific evidence that the use of thimerosal in vaccines presents any risk to human health,” writes Dr. Katherine King in one of today’s Pediatrics articles. Dozens of studies and a massive review at the Institute of Medicine back this up.

Thimerosal in vaccines is not a problem. But what is a problem is thimerosal’s PR image. Again, from one of today’s AAP articles: “Given the complexity of the science involved in making guidelines, the polarity between vaccine advocates and those believing their children have been harmed, the media’s attraction to controversy, and, in retrospect, inadequate follow-up education about the issues to clinicians and the general public, it is not surprising that the steps taken left misunderstanding and anxiety in the United States and concerns in the global public health community.”

Basically, they’re saying, yea, we kinda screwed up with conveying that thimerosal really IS safe after all. We wanted to be over-cautious before, and we were, and that was good, but now we’ve sorta dropped the ball on following through in letting you know that YOU HAVE NOTHING TO WORRY ABOUT with the ethylmercury in thimerosal. As Dr. Walter Orenstein today’s AAP articles, “Had the evidence that is available now been available in 1999, the policy reducing thimerosal use would likely have not been implemented. Furthermore, in 2008 the World Health Organization endorsed the use of thimerosal in vaccines.”

But apparently, the WHO’s endorsement can’t overcome thimerosal’s PR image problem in the eyes of the UN. And so the UN is short-sightedly and dangerously trying to ban thimerosal in vaccines.

Well, that just means getting rid of it in flu vaccines (many of which don’t even have thimerosal since they’re single-dose), so what’s the big deal anyway? The big deal is that not all countries got rid of thimerosal in their childhood vaccines. Many high-income countries like the U.S. did – because they could afford to be overly cautious.

But more than 120 middle- and low-income countries – including the developing countries where vaccine-preventable diseases have the highest rates of infection and death – have continued using thimerosal-containing vaccines because the preservative allows them to make cheaper vaccines that withstand less rigorous storage without compromising safety.

Getting rid of thimerosal would mean overhauling vaccine production and storage in those countries, which the WHO estimates would cost more than $300 million for vaccines supplied by UNICEF or the Pan American Health Organization alone. As Dr. King argues, “it is banning thimerosal that would cause an injustice to those living in low- and middle-income countries and relying on these vaccines for effective protection against many harmful infectious diseases.”

Why does this matter to people in the U.S. or in other higher income countries? Because we live in a global world. Vaccines with thimerosal are currently used to immunize about 84 million children across the world every year, saving an estimated 1.4 million lives from vaccine-preventable diseases.That also includes lives saved in developed countries, where a future outbreak could potentially be imported from other countries in which a vaccination program may have ceased following a thimerosal ban.

More simply put: If the UN forces the removal of thimerosal from vaccines, then 84 million children risk not getting vaccinated (and/or vaccinated on time) due to delays in vaccine production or due to a shortage of vaccines because of increasing costs. This, in turn, could (and likely would) mean an increase in vaccine-preventable infections, which will, in turn, kill more children worldwide and risk disease carriage to other countries.

Over and beyond the increases in vaccine-preventable infections and deaths throughout the world, a thimerosal ban in vaccines could also still pose problems for developed countries. In an emergency, as Dr. Orenstein and colleagues argue, not being able to manufacture vaccines with thimerosal could endanger lives during an epidemic if it slows down vaccine production. This proposed UN ban – and the necessity of its removal – matters.

Dr. Cooper and Dr. Katz – again, both pediatricians who were closely involved in the original 1999 decision to pull thimerosal out of vaccines – sum it up best: “The World Health Organization recommendation to delete the ban on thimerosal must be heeded or it will cause tremendous damage to current programs to protect all children from death and disability caused by vaccine-preventable diseases.”