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."

Shocker: This Electric Eel Delivers More Voltage Than Any Creature on Earth

stacey_newman/iStock via Getty Images
stacey_newman/iStock via Getty Images

Eels are proving to be more slippery than previously believed. A newly identified species of these skinny fish (yes, eels are really fish) delivers more electric voltage than any other creature on the planet.

All species in their taxonomic order (Gymnotiformes) are capable of producing a modest electrical field to help them navigate, a perk that compensates for their poor vision. But electric eels (in the genus Electrophorus) pack a far more potent punch. They bear three organs full of cells that can produce electricity on demand. The cells act as a defense mechanism and can effectively taser prey into submission.

In a study published in Nature Communications, researchers collected more than 100 electric eels in the Amazon region and analyzed their DNA, voltage, and habitat. To their surprise, they found that the single known species of electric eel, Electrophorus electricus, was actually three distinct species. They gave the two new ones the very heavy metal names of E. varii and E. voltai. The latter (named for Alessandro Volta, who invented the electric battery) produced the strongest shock: 860 volts, topping the previous record of 650 volts.

Why the varying strength? The researchers suggested that some eels occupy water with low salt content, and therefore reduced conductivity. A stronger charge may be needed to deliver an effective jolt.

While those numbers sound formidable, their low current means a shock wouldn’t necessarily be harmful to a human. Voltage is the measure of pressure of the flow of electrons; current, or amperage, is the volume of electrons. Eels have high voltage but low current; household power outlets have lower voltage but more current and can be deadly. Eels might startle you with a shock, but it won't be fatal.

If you should find yourself in a school of electric eels bent on subduing you, however, the shocks could result in brief incapacitation that could lead to drowning or an aggravation of an existing heart condition. The study authors hope to eventually film a coordinated eel attack on (non-human) prey.

The discovery of two new species was “quite literally shocking,” lead author Carlos David de Santana told The New York Times.

[h/t Phys.org]

Does the Full Moon Really Make People Act Crazy?

iStock.com/voraorn
iStock.com/voraorn

Along with Mercury in retrograde, the full moon is a pretty popular scapegoat for bad luck and bizarre behavior. Encounter someone acting strangely? Blame it on the lunar phases! It's said that crime rates increase and emergency rooms are much busier during the full moon (though a 2004 study debunked this claim). Plus, there's that whole werewolf thing. Why would this be? The reasoning is that the moon, which affects the ocean's tides, probably exerts a similar effect on us, because the human body is made mostly of water.

This belief that the moon influences behavior is so widely held—reportedly, even 80 percent of nurses and 64 percent of doctors think it's true, according to a 1987 paper published in the Journal of Emergency Medicine [PDF]—that in 2012 a team of researchers at Université Laval's School of Psychology in Canada decided to find out if mental illness and the phases of the moon are linked [PDF].

To test the theory, the researchers evaluated 771 patients who visited emergency rooms at two hospitals in Montreal between March 2005 and April 2008. The patients chosen complained of chest pains, which doctors could not determine a medical cause for the pains. Many of the patients suffered from panic attacks, anxiety and mood disorders, or suicidal thoughts.

When the researchers compared the time of the visits to the phases of the moon, they found that there was no link between the incidence of psychological problems and the four lunar phases, with one exception: in the last lunar quarter, anxiety disorders were 32 percent less frequent. "This may be coincidental or due to factors we did not take into account," Dr. Geneviève Belleville, who directed the team of researchers, said. "But one thing is certain: we observed no full-moon or new-moon effect on psychological problems."

So rest easy (or maybe not): If people seem to act crazy during the full moon, their behavior is likely pretty similar during the rest of the lunar cycle as well.

Have you got a Big Question you'd like us to answer? If so, let us know by emailing us at bigquestions@mentalfloss.com.

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