The phonological deficit hypothesis is a prevalent cognitive-level explanation for the cause of reading difficulties and

dyslexia Dyslexia (), previously known as word blindness, is a learning disability that affects either reading or writing. Different people are affected to different degrees. Problems may include difficulties in spelling words, reading quickly, wri ...

. It stems from evidence that individuals with dyslexia tend to do poorly on tests which measure their ability to decode nonsense words using conventional phonetic rules, and that there is a high correlation between difficulties in connecting the sounds of language to letters (

phonemic awareness Phonemic awareness is a part of phonological awareness in which listeners are able to hear, identify and manipulate phonemes, the smallest mental units of sound that help to differentiate units of meaning (morphemes). Separating the spoken word " ...

) and reading delays or failure in children. The basic hypothesis is that reading failure or dyslexia stems from a functional or structural deficit in left hemispheric brain areas associated with processing the sounds of language. Some researchers have studied the structure and function of neural pathways in the language areas of the

brain The brain is an organ (biology), organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It consists of nervous tissue and is typically located in the head (cephalization), usually near organs for ...

. Others have focused on the perception of short or rapidly varying sounds of language, positing that the core deficit is one of timing rather than of overall function. Since the 1990s, the phonological deficit hypothesis has been the dominant explanation favored by researchers as to the probable cause of dyslexia, but it is only one of several competing theories. Critics of the phonological hypothesis point out that it fails to account for symptoms of dyslexia unrelated to phonetic decoding difficulties, such as problems with short-term memory, visual processing issues, or difficulties with balance and small motor coordination that are common to many dyslexic children and adults. They also argue that much of the evidence for the theory is based on

circular reasoning Circular reasoning (, "circle in proving"; also known as circular logic) is a fallacy, logical fallacy in which the reasoner begins with what they are trying to end with. Circular reasoning is not a formal logical fallacy, but a pragmatic defect ...

, in that phonological weakness is seen as both a defining symptom of dyslexia and as its underlying cause.

References

General references

* {{Dyslexia Dyslexia Learning disabilities Phonetics Theories of dyslexia

See also

References

General references