Dyslexia:
Explainations from Science

A Compilation by: Dyslexia & Dyscalculia Support Services of Shiawassee County
(517) 729-9108 Renee Newman, M.S., Director

1984 HARVARD UNIVERSITY / DR. GALABURDA

Dyslexia, which occurs in 15% of the population, is a normal variation of the human brain (evolution), not a disorder. During fetal development: Fetal enlargement- superior development- of the Right Side of the brain. The Right deals with spatial perception, faces, art, and music. It stores movement and touch information about man-made things.This results in superior talent in art, architecture, engineering, photography, mechanics, athletics, theoretical physics, and brain surgery.

Fetal growth slows in the smaller Left Side of the brain. The Left contains the Broca Area, a primary language processing center.This results in an inconsistent visual memory for the printed word. The ability of the Left side to process rapid sensory signals is diminished.

1991 HARVARD UNIVERSITY / DR. LIVINGSTONE

In reading, light strikes the photo receptors in the retina. Then information is processed in the midbrain by magno and parvo cells, then onto the visual cortex for further processing.

Dyslexics have an abnormality that slows down a major pathway so that two kinds of visual information are not received in the proper sequence.

The Magnocellular system does fast processing for perceiving position, motion, shape, and low contrast. In a dyslexic brain, Magno cell layout is more disorganized. The smaller than normal cells conduct impulses more slowly. Low contrast processing is slower. When visual stimuli is presented in rapid succession, only partial perception occurs. Result: Words that blur, fuse, or jump off the page.

COLORED LENSES: Blue colored lenses (over head projector sheets) help 80% of users. Why? Magno cells are inhibited by diffuse red light. The blue filter may remove enough of the red light to allow cells to function normally.

1991 HARVARD UNIVERSITY / DR. GALABURDA

Dyslexia could be an auto immune disease, preventable before or soon after birth. Antibodies destroy a protein unique to Magno cells. Magno cell performance is impaired in infancy. Abnormally processed sights and sounds begin to shape the infant brain, and cause it to be wired up differently. For survival, functions usually wired into the magnocellular system, now bypass it, and are rewired in other locales- possibly, to areas capable, but less specific- with unreliable processing results (perceptual inconsistencies.)

1992 RUTGERS UNIVERSITY / DR. TALLAL

It takes 4-40 ms to say the /b/ or /d/ sounds. The language impaired need 80 ms to distinguish initial speech sounds (twice as long). An 8 ms pause is normally required to perceive a change in tones; for the language impaired, a 300+ ms pause is required between tone changes for perception to occur.

1992 RESEARCH:

Upon experience, the brain records information in those areas engaged by the senses.

Link to Diagnosis of Specific Learning Disabilities, Club Brilliant & Local Stats, Dyscalculia Symptoms, Dyslexia History, A Scientific Explanation, and the LD Check List