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Scientists May Have Found the Real Cause of Dyslexia—And a Way to Treat It

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Dyslexia is often described as trying to read letters as they jump around the page. Because of its connections to reading difficulties and trouble in school, the condition is often blamed on the brain. But according to a new study published in Proceedings of the Royal Society B, the so-called learning disability may actually start in the eyes.

As The Guardian reports, a team of French scientists say they've discovered a key physiological difference between the eyes of those with dyslexia and those without it. Our eyes have tiny light-receptor cells called rods and cones. The center of a region called the fovea is dominated by cones, which are also responsible for color perception.

Just as most of us have a dominant hand, most have a dominant eye too, which has more neural connections to the brain. The study of 60 people, divided evenly between those with dyslexia and those without, found that in the eyes of non-dyslexic people, the arrangement of the cones is asymmetrical: The dominant eye has a round, cone-free hole, while the other eye has an unevenly shaped hole. However, in people with dyslexia, both eyes have the same round hole. So when they're looking at something in front of them, such as a page in a book, their eyes perceive exact mirror images, which end up fighting for visual domination in the brain. This could explain why it's sometimes impossible for a dyslexic person to distinguish a "b" from a "d" or an "E" from a "3".

These results challenge previous research that connects dyslexia to cognitive abilities. In a study published earlier this year, people with the condition were found to have a harder time remembering musical notes, faces, and spoken words. In light of the new findings, it's unclear whether this is at the root of dyslexia or if growing up with vision-related reading difficulties affects brain plasticity.

If dyslexia does come down to some misarranged light-receptors in the eye, diagnosing the disorder could be as simple as giving an eye exam. The explanation could also make it easy to treat without invasive surgery. In the study, the authors describe using an LED lamp that blinks faster than the human eye can perceive to "cancel out" one of the mirror images perceived by dyslexic readers, leaving only one true image. The volunteers who read with it called it a "magic lamp." The researchers hope to further experiment with it to see see if it's a viable treatment option for the millions of people living with dyslexia.

[h/t The Guardian]

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Your $10 Donation Can Help an Underprivileged Child See A Wrinkle in Time for Free
Disney Enterprises, Inc.
Disney Enterprises, Inc.

Theater chain AMC is teaming with the Give a Child the Universe initiative to help underprivileged kids see A Wrinkle in Time for free through ticket donations. The initiative was started by Color of Change, a nonprofit advocacy group that designs “campaigns powerful enough to end practices that unfairly hold Black people back, and champion solutions that move us all forward.”

"Color of Change believes in the power of images and supports those working to change the rules in Hollywood so that inclusive, empathetic and human portrayals of black people and people of color are prominent on the screen,” the initiative’s executive director, Rashad Robinson, said in a statement:

Director Ava DuVernay’s A Wrinkle in Time is the perfect subject for the group because, as Robinson puts it, “By casting a black teenage actress, Storm Reid, as the heroine at the center of this story, the filmmakers and the studio send a powerful message to millions of young people who will see someone like them embracing their individuality and strength to save the world.”

The movie touts a diverse cast that includes Mindy Kaling, Oprah Winfrey, Reese Witherspoon, Zach Galifianakis, and Chris Pine. The most important member of the cast, though, is 14-year-old Storm Reid, who plays the main character Meg Murry, a young girl who tries to save her father (Pine) who is trapped in another dimension. The movie is based on the acclaimed 1962 fantasy novel by author Madeleine L'Engle.

If you’d like to donate a ticket (or more), you can just head over to the Give a Child the Universe website and pledge an amount. AMC will provide one ticket to children and teens nationwide for every $10 given to the cause.

And if you’re interested in seeing the movie yourself, A Wrinkle in Time opens on March 9, 2018.

[h/t E! Online]

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Dodo: © Oxford University, Oxford University Museum of Natural History. Background: iStock
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Head Case: What the Only Soft Tissue Dodo Head in Existence Is Teaching Scientists About These Extinct Birds
Dodo: © Oxford University, Oxford University Museum of Natural History. Background: iStock
Dodo: © Oxford University, Oxford University Museum of Natural History. Background: iStock

Of all the recently extinct animals, none seems to excite the imagination quite like the dodo—a fact Mark Carnall has experienced firsthand. As one of two Life Collections Managers at the UK's Oxford University Museum of Natural History, he’s responsible for nearly 150,000 specimens, “basically all the dead animals excluding insects and fossils,” he tells Mental Floss via email. And that includes the only known soft tissue dodo head in existence.

“In the two and a bit years that I’ve been here, there’s been a steady flow of queries about the dodo from researchers, artists, the public, and the media,” he says. “This is the third interview about the dodo this week! It’s definitely one of the most popular specimens I look after.”

The dodo, or Raphus cucullatus, lived only on the island of Mauritius (and surrounding islets) in the Indian Ocean. First described by Vice Admiral Wybrand van Warwijck in 1598, it was extinct less than 100 years later (sailors' tales of the bird, coupled with its rapid extinction, made many doubt that the dodo was a real creature). Historians still debate the extent that humans ate them, but the flightless birds were easy prey for the predators, including rats and pigs, that sailors introduced to the isolated island of Mauritius. Because the dodo went extinct in the 1600s (the actual date is still widely debated), museum specimens are very, very rare. In fact, with the exception of subfossils—the dark skeletons on display at many museums—there are only three other known specimens, according to Carnall, “and one of those is missing.” (The fully feathered dodos you might have seen in museums? They're models, not actual zoological specimens.)

A man standing with a Dodo skeleton and a reconstructed model of the extinct bird
A subfossil (bone that has not been fully fossilized) Dodo skeleton and a reconstructed model of the extinct bird in a museum in Wales circa 1938.
Becker, Fox Photos/Getty Images

Since its extinction was confirmed in the 1800s, Raphus cucullatus has been an object of fascination: It’s been painted and drawn, written about and scientifically studied, and unfairly become synonymous with stupidity. Even now, more than 300 years since the last dodo walked the Earth, there’s still so much we don’t know about the bird—and Oxford’s specimen might be our greatest opportunity to unlock the mysteries surrounding how it behaved, how it lived, how it evolved, and how it died.

 
 

To put into context how old the dodo head is, consider this: From the rule of Oliver Cromwell to the reign of Queen Elizabeth II, it has been around—and it’s likely even older than that. Initially an entire bird (how exactly it was preserved is unclear), the specimen belonged to Elias Ashmole, who used his collections to found Oxford’s Ashmolean Museum in 1677. Before that, it belonged to John Tradescant the Elder and his son; a description of the collection from 1656 notes the specimen as “Dodar, from the Island Mauritius; it is not able to flie being so big.”

And that’s where the dodo’s provenance ends—beyond that, no one knows where or when the specimen came from. “Where the Tradescants got the dodo from has been the subject of some speculation,” Carnall says. “A number of live animals were brought back from Mauritius, but it’s not clear if this is one of [those animals].”

Initially, the specimen was just another one of many in the museum’s collections, and in 1755, most of the body was disposed of because of rot. But in the 19th century, when the extinction of the dodo was confirmed, there was suddenly renewed interest in what remained. Carnall writes on the museum’s blog that John Duncan, then the Keeper of the Ashmolean Museum, had a number of casts of the head made, which were sent to scientists and institutions like the British Museum and Royal College of Surgeons. Today, those casts—and casts of those casts—can be found around the world. (Carnall is actively trying to track them all down.)

The Oxford University Dodo head with scoleric bone and the skin on one side removed.
The Oxford University Dodo head with skin and sclerotic ring.
© Oxford University, Oxford University Museum of Natural History // Used with permission

In the 1840s, Sir Henry Acland, a doctor and teacher, dissected one side of the head to expose its skeleton, leaving the skin attached on the other side, for a book about the bird by Alexander Gordon Melville and H.E. Strickland called The dodo and its kindred; or, The history, affinities, and osteology of the dodo, solitaire, and other extinct birds of the islands Mauritius, Rodriguez and Bourbon. Published in 1848, “[It] brought together all the known accounts and depictions of the dodo,” Carnall says. The Dodo and its kindred further raised the dodo’s profile, and may have been what spurred schoolteacher George Clark to take a team to Mauritius, where they found the subfossil dodo remains that can be seen in many museums today.

Melville and Strickland described Oxford’s specimen—which they believed to be female—as being “in tolerable preservation ... The eyes still remain dried within the sockets, but the corneous extremity of the beak has perished, so that it scarcely exhibits that strongly hooked termination so conspicuous in all the original portraits. The deep transverse grooves are also visible, though less developed than in the paintings.”

Today, the specimen includes the head as well as the sclerotic ring (a bony feature found in the eyes of birds and lizards), a feather (which is mounted on a microscope slide), tissue samples, the foot skeleton, and scales from the foot. “Considering it’s been on display in collections and museums, pest eaten, dissected, sampled and handled by scientists for over 350 years,” Carnall says, “it’s in surprisingly good condition.”

 
 

There’s still much we don’t know about the dodo, and therefore a lot to learn. As the only soft tissue of a dodo known to exist, the head has been studied for centuries, and not always in ways that we would approve of today. “There was quite some consideration about dissecting the skin off of the head by Sir Henry Acland,” Carnall says. “Sadly there have also been some questionable permissions given, such as when [Melville] soaked the head in water to manipulate the skin and feel the bony structure. Excessive handling over the years has no doubt added to the wear of the specimen.”

Today, scientists who want to examine the head have to follow a standard protocol. “The first step is to get in touch with the museum with details about access requirements ... We deal with enquiries about our collections every single day,” Carnall says. “Depending on the study required, we try to mitigate damage and risk to specimens. For destructive sampling—where a tissue sample or bone sample is needed to be removed from the specimen and then destroyed for analysis—we weigh up the potential importance of the research and how it will be shared with the wider community.”

In other words: Do the potential scientific gains outweigh the risk to the specimen? “This,” Carnall says, “can be a tough decision to make.”

The head, which has been examined by evolutionary biologist Beth Shapiro and extinction expert Samuel Turvey as well as dodo experts Julian Hume and Jolyon Parish, has been key in many recent discoveries about the bird. “[It] has been used to understand what the dodo would have looked like, what it may have eaten, where it fits in with the bird evolutionary tree, island biogeography and of course, extinction,” Carnall says. In 2011, scientists took measurements from dodo remains—including the Oxford specimen—and revised the size of the bird from the iconic 50 pounder seen in paintings to an animal “similar to that of a large wild turkey.” DNA taken from specimen’s leg bone has shed light on how the dodo came to Mauritius and how it was related to other dodo-like birds on neighboring islands [PDF]. That DNA also revealed that the dodo’s closest living relative is the Nicobar pigeon [PDF].

A nicobar pigeon perched on a bowl of food.
A nicobar pigeon.
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Even with those questions answered, there are a million more that scientists would like to answer about the dodo. “Were there other species—plants, parasites—that depended on the dodo?” Carnall asks. “What was the soft tissue like? ... How and when did the dodo and the related and also extinct Rodrigues solitaire colonize the Mascarene Islands? What were their brains like?”

 
 

Though it’s a rare specimen, and priceless by scientific standards, the dodo head is, in many ways, just like all the rest of the specimens in the museum’s collections. It’s stored in a standard archival quality box with acid-free tissue paper that’s changed regularly. (The box is getting upgraded to something that Carnall says is “slightly schmancier” because “it gets quite a bit of use, more so than the rest of the collection.”) “As for the specific storage, we store it in vault 249 and obviously turn the lasers off during the day,” Carnall jokes. “The passcode for the vault safe is 1234ABCD …”

According to Carnall, even though there are many scientific and cultural reasons why the dodo head is considered important, to him, it isn’t necessarily more important than any of the other 149,999 specimens he’s responsible for.

“Full disclosure: All museum specimens are equally important to collections managers,” he says. “It is a huge honor and a privilege to be responsible for this one particular specimen, but each and every specimen in the collection also has the power to contribute towards our knowledge of the natural world ... This week I was teaching about a species of Greek woodlouse and the molluscs of Oxfordshire. We know next to nothing about these animals—where they live, what they eat, the threats to them, and the predators that rely on them. The same is true of most living species, sadly. But on the upside, there’s so much work to be done!”

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