What is Dyslexia ?

We have often heard about the disease named "Dyslexia". But how many of us actually know about the details of this disease? I'm sure that not many of you might be aware of its complications and effects. Let me throw light on this subject.

Types of Dyslexia

Surface Dyslexia- Surface dyslexia is characterized by subjects who can read known words but who have trouble reading words that are irregular. Surface dyslexia is the outcome of an individual who cannot function using the lexical procedure for reading out loud. The lexical procedure includes sounding out a word through the use of a past word already known.

Phonological Dyslexia-Phonological dyslexia is characterized by subjects who can read aloud both regular and irregular words but have difficulties with non-words and with connecting sounds to symbols, or with sounding out words. Phonological processing tasks predict reading accuracy and comprehension.

Double Deficit Dyslexia-Researchers have identified a deficit related to "naming speed", which relates to the ability of students to rapidly verbalize the names of symbols such as letters and numbers when tested.

I hope that the above article helps you understand about this disease in a better manner.

Theories

Evolutionary Hypothesis

This theory posits that reading is an unnatural act, and carried out by humans for an exceedingly brief period in our evolutionary history. It has been less than a hundred years that most western societies promoted reading by the mass population and therefore the forces that shape our behavior have been weak.

Identified by Oswald Berkhan in 1881, [3] the term 'dyslexia' was later coined in 1887 by Rudolf Berlin, an ophthalmologist practicing in Stuttgart, Germany.[4] He used the term to refer to a case of a young boy who had a severe impairment in learning to read and write in spite of showing typical intellectual and physical abilities in all other respects.

Phonological hypothesis

The phonological hypothesis postulates that dyslexics have a specific impairment in the representation, storage and/or retrieval of speech sounds. It explains dyslexics' reading impairment on the basis that learning to read an alphabetic system requires learning the grapheme/phoneme correspondence, i.e. the correspondence between letters and constituent sounds of speech.