Learning to Read as an Adult Changes Deep Regions of the Brain

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In the evolutionary history of humans, reading and writing are relatively new functions. As a result, in order to read written language, human brains have had to recruit and adapt parts of the visual system to interface with language centers. This is a process researchers have long believed occurred primarily in the cerebral cortex, the outer layer of the brain. But in a new study where illiterate people in their thirties were trained to read over six months, researchers have discovered that reading actually activates much deeper brain structures as well, opening doors to a better understanding of how we learn, and possible new interventions for dyslexia. Their results were recently published in the journal Science Advances.

In order to learn to read, "a kind of recycling process has to take place in the brain," Falk Huettig, one of the collaborating researchers at Max Planck Institute for Human Cognitive and Brain Sciences, tells Mental Floss by email. "Areas evolved for the recognition of complex objects, such as faces, become engaged in translating letters into language.”

To study this process in the brain, researchers selected participants from India, where the literacy rate is about 63 percent, a rate influenced by poverty, which limits educational access, especially for girls and women. Most of the participants in this study were women in their thirties who came into the study unable to read a single word.

They divided the participants into a group that received reading training intervention and a control group that was not trained. Both groups underwent functional magnetic resonance imaging (fMRI) brain scans before and after the six-month study. Some participants were excluded due to incomplete scanning sessions, leaving a total of 30 participants in the final analysis.

They were taught to read Devanagari, the script upon which Hindi and some other languages of South Asia are based. It's an alpha-syllabic script composed of complex characters that describe whole syllables or words.

The instructor was a professional teacher who followed the locally established method of reading instruction. During the first month of instruction, the participants first were taught to read and write 46 primary Devanagari characters simultaneously. After learning the letters and reading single words, they were taught two-syllable words. In all, they studied approximately 200 words in the first month.

In the second month, the participants were then taught to read and write simple sentences, and in the third month, they learned more complex, three-syllable words. Finally, in the second half of the program, participants learned some basic grammar rules. "For example, the participants learned about the differences between nouns, pronouns, verbs, proverbs, and adjectives, and also about basic rules of tense and gender," Huettig says.

Within six months, participants who could read between zero and eight words even before the training had reached a first-grade level of reading, according to Huettig. "This process was quite remarkable," Huettig says. "Learning to read is quite a complex skill, as arbitrary script characters must be mapped onto the corresponding units of spoken language."

When the researchers looked at the brain scans taken before and after the six-month training, Huettig says they expected to simply replicate previous findings: that changes are limited to the cortex, which is known to adapt quickly to new challenges.

What they didn't expect was to see changes in deeper parts of the brain. "We observed that the learning process leads to a reorganization that extends to deep brain structures in the thalamus and the brainstem." More specifically, learning to read had an impact on a part of the brainstem called the superior colliculus as well as the pulivinar, located in the thalamus, which "adapt the timing of their activity patterns to those of the visual cortex," Heuttig explains.

These deep brain structures help the visual cortex filter important information from the flood of visual input—even before we consciously perceive it. "It seems that these brain systems increasingly fine-tune their communication as learners become more and more proficient in reading," he says.

In essence, the more these participants read, the better they became at it. The research also revealed that the adult brain is more adaptable than previously understood. "Even learning to read in your thirties profoundly transforms brain networks," Huettig says. "The adult brain is remarkably flexible to adapt to new challenges."

Even more promising, these results shed new light on a possible cause of dyslexia, a language-processing disorder, which researchers have long attributed to dysfunctions of the thalamus. Since just a few months of reading training can modify the thalamus, Huettig says, "it could also be that affected people show different brain activity in the thalamus, just because their visual system is less well-trained than that of experienced readers."

Huettig feels that the social implications of this kind of research are huge, both for people effected by dyslexia as well as the hundreds of millions of adults who are completely or functionally illiterate around the world. Huettig says the new findings could help "put together literacy programs that have the best chance of succeeding to help these people."

A Simple Skin Swab Could Soon Identify People at Risk for Parkinson's

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iStock.com/stevanovicigor

More than 200 years have passed since physician James Parkinson first identified the degenerative neurological disorder that bears his name. Over five million people worldwide suffer from Parkinson’s disease, a neurological condition characterized by muscle tremors and other symptoms. Diagnosis is based on those symptoms rather than blood tests, brain imaging, or any other laboratory evidence.

Now, science may be close to a simple and non-invasive method for diagnosing the disease based on a waxy substance called sebum, which people secrete through their skin. And it’s thanks to a woman with the unique ability to sniff out differences in the sebum of those with Parkinson's—years before a diagnosis can be made.

The Guardian describes how researchers at the University of Manchester partnered with a nurse named Joy Milne, a "super smeller" who can detect a unique odor emanating from Parkinson's patients that is unnoticeable to most people. Working with Tilo Kunath, a neurobiologist at Edinburgh University, Milne and the researchers pinpointed the strongest odor coming from the patients' upper backs, where sebum-emitting pores are concentrated.

For a new study in the journal ACS Central Science, the researchers analyzed skin swabs from 64 Parkinson's and non-Parkinson's subjects and found that three substances—eicosane, hippuric acid, and octadecanal—were present in higher concentrations in the Parkinson’s patients. One substance, perillic aldehyde, was lower. Milne confirmed that these swabs bore the distinct, musky odor associated with Parkinson’s patients.

Researchers also found no difference between patients who took drugs to control symptoms and those who did not, meaning that drug metabolites had no influence on the odor or compounds.

The next step will be to swab a a much larger cohort of Parkinson’s patients and healthy volunteers to see if the results are consistent and reliable. If these compounds are able to accurately identify Parkinson’s, researchers are optimistic that it could lead to earlier diagnosis and more effective interventions.

[h/t The Guardian]

World’s Oldest Stored Sperm Has Produced Some Healthy Baby Sheep

A stock photo of a lamb
A stock photo of a lamb
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It’s not every day that you stumble across a 50-year-old batch of frozen sheep sperm. So when Australian researchers rediscovered a wriggly little time capsule that had been left behind by an earlier researcher, they did the obvious: they tried to create some lambs. As Smithsonian reports, they pulled it off, too.

The semen, which came from several prize rams, had been frozen in 1968 by Dr. Steve Salamon, a sheep researcher from the University of Sydney. After bringing the sample out of storage, researchers thawed it out and conducted a few lab tests. They determined that its viability and DNA integrity were still intact, so they decided to put it to the ultimate test: Would it get a sheep pregnant? The sperm was artificially inseminated into 56 Merino ewes, and lo and behold, 34 of them became pregnant and gave birth to healthy lambs.

Of course, this experiment wasn’t just for fun. They wanted to test whether decades-old sperm—frozen in liquid nitrogen at -320°F—would still be viable for breeding purposes. Remarkably, the older sperm had a slightly higher pregnancy rate (61 percent) than sheep sperm that had been frozen for 12 months and used to impregnate ewes in a different experiment (in that case, the success rate was 59 percent).

“We believe this is the oldest viable stored semen of any species in the world and definitely the oldest sperm used to produce offspring,” researcher Dr. Jessica Rickard said in a statement.

Researchers say this experiment also lets them assess the genetic progress of selective breeding over the last five decades. “In that time, we’ve been trying to make better, more productive sheep [for the wool industry],” associate professor Simon de Graaf said. “This gives us a resource to benchmark and compare.”

[h/t Smithsonian]

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