Scientists may have found a cause of dyslexia
Scientists may have found a cause of dyslexia
In people with the reading disability, the cells were arranged in matching patterns in both eyes, which may be to blame for confusing the brain by producing “mirror” images, the co-authors wrote in the journal Proceedings of the Royal Society B.
In non-dyslexic people, the cells are arranged asymmetrically, allowing signals from the one eye to be overridden by the other to create a single image in the brain.
“Our observations lead us to believe that we indeed found a potential cause of dyslexia,” study co-author Guy Ropars of the University of Rennes, told AFP.
It offers a “relatively simple” method of diagnosis, he added, by simply looking into a subject’s eyes.
Furthermore, “the discovery of a delay (of about 10 thousandths of a second) between the primary image and the mirror image in the opposing hemispheres of the brain, allowed us to develop a method to erase the mirror image that is so confusing for dyslexic people” — using an LED lamp.
Like being left- or right-handed, human beings also have a dominant eye.
As most of us have two eyes, which record slightly different versions of the same image, the brain has to select one of the two, creating a “non-symmetry.”
Many more people are right-eyed than left, and the dominant eye has more neural connections to the brain than the weaker one.
Image signals are captured with rods and cones in the eye — the cones being responsible for color.
The majority of cones, which come in red, green and blue variants, are found in a small spot at the center of the cornea of the eye known as the fovea. But there is a small hole (about 0.1-0.15 millimeters in diameter) with no blue cones.
In the new study, Ropars and colleague Albert le Floch spotted a major difference between the arrangement of cones between the eyes of dyslexic and non-dyslexic people enrolled in an experiment.
In non-dyslexic people, the blue cone-free spot in one eye — the dominant one, was round and in the other eye unevenly shaped.
In dyslexic people, both eyes have the same, round spot, which translates into neither eye being dominant, they found.
“The lack of asymmetry might be the biological and anatomical basis of reading and spelling disabilities,” said the study authors.
Dyslexic people make so-called “mirror errors” in reading, for example confusing the letters “b” and “d.”
“For dyslexic students their two eyes are equivalent and their brain has to successively rely on the two slightly different versions of a given visual scene,” the duo added.
The team used an LED lamp, flashing so fast that it is invisible to the naked eye, to “cancel” one of the images in the brains of dyslexic trial participants while reading.
In initial experiments, dyslexic study participants called it the “magic lamp,” said Ropars, but further tests are required to confirm the technique really works.
About 700 million people in the world are known to suffer from dyslexia — about one in ten of the global population.
Ta’ateemah: Giving Eid a Hijazi flavor
- Dibyaza is made of melted dried apricots, roasted nuts, figs, peach and sugary dates to create a marmalade-like dish that can be enjoyed with or without bread
- The dibyaza is also similar to an Egyptian dish called khoshaf, but dibyaza is often partnered with shureik — a donut-shaped bread with sesame sprinkled all over it
JEDDAH: Ta’ateemah is the name of the breakfast feast Hijazis enjoy on the first day of Eid Al-Fitr. It is derived from the Arabic word, itmah, or darkness, because the dishes served are light, just like midnight snacks.
Muslims around the world celebrate Eid Al-Fitr to feast after fasting for the holy month of Ramadan. But it is called Al-Fitr from iftar, or breakfast when translated to English, which is a meal Muslims do not get to experience during that month.
The first day of Eid is a day where they finally can, and they greet the day with joy by heading to Eid prayers and then enjoying this traditional meal.
Amal Turkistani, mother of five from Makkah who now lives in Jeddah, told Arab News all about a special Eid dish.
“The most famous dish is the dibyaza, and making a dish of it is a work of art that I can proudly say I excel at. Dibyaza is made of melted dried apricots, roasted nuts, figs, peach and sugary dates to create a marmalade-like dish that can be enjoyed with or without bread.”
She revealed that dibyaza is not a quick meal — it is usually prepared a day or two before Eid with the ingredients simmered to reach the correct liquid thickness.
No one can trace the origins of dibyaza — it remains a mystery. Some people claim it originated in Turkey, while others attribute it to the Indians.
A number of women who are famous for their dibyaza agreed that it is a Makkawi dish. This marmalade dish was developed and improved, with tiny details to distinguish it.
The dibyaza is also similar to an Egyptian dish called khoshaf, but dibyaza is often partnered with shureik — a donut-shaped bread with sesame sprinkled all over it.
Turkistani said sweet shops sell 1 kg of dibyaza for SR50 ($13), competing with housewives who make their own.
“I think it is always tastier when it’s homemade because of all the love that goes into making it. It’s also a wonderful way to greet your family and neighbors with this special dish that you only enjoy once a year.”
Her younger sister, Fatin, said: “My siblings always have Eid breakfast at my place, so it’s up to me to prepare the feast. My sister spares me the exhausting dibyaza-making, so I prepare two main dishes: Minazalla, which is a stew of lamb chops with tahini and a tomato chicken stew.
“She also serves what we call nawashif, or dry food, like different types of cheese and olives, pickled lemon, labneh, red mish — a mixture of white cheese, yogurt and chili pepper and halwa tahini,” Amal said.
Mohammed Ibrahim, 23, from Makkah, told Arab News: “It always feels unique to have minazalla and nawashif during Eid, and not just because it is followed by the Eidiyah.”