User:DylanLudwick/sandbox

Classification
Deep dyslexia is classified as a reading disorder that is acquired in previously literate adults as a consequence of a brain injury. This injury results in the occurrence of semantic errors during reading and the impairment of nonword reading. Deep dyslexia is similar to phonological dyslexias in that both have disability in the phonological reading route. Although thought to be distinct disorders, in recent times some have argued that they should be considered variants that differ in severity. Overall, the reading ability of a deep dyslexic is significantly more impaired than the ability seen in phonological dyslexics because their semantic reading route is also impaired, leaving no intact pathways to reading.

Signs and Symptoms
The Symptom-complex can be summarized as follows: Semantic errors while reading aloud (e.g. ripple → water), an inability to read nonwords aloud (e.g. Jilp), and additional reading errors such as visual errors (e.g. perform → perfume), function-word substitutes (e.g. for → and), and derivational errors (e.g. ill → illness)

Models and Hypotheses of Deep Dyslexia
Multiple theories have been proposed regarding the methodology of deep dyslexia and the pathways of impaired reading performance. These theories have resulted in several models designed to conceptualize the symptom-complex found in deep dyslexics.

Dual Route Model
The Morton and Patterson (Dual Route) Model is based upon the dual-route model for reading. It proposes that the occurrence of semantic errors alongside an inability to read nonwords aloud must be due to multiple loci of damage within this dual-route model. Because a deep dyslexic cannot read aloud nonwords, a disruption in the phonological process is assumed, forcing reading to proceed through the semantic route. However, deep dyslexics also produce semantic errors while reading, alluding to damage in this pathway as well.

Continuum Model
The Glosser and Friedman (Continuum) Model is based upon the concept that deep dyslexia and phonological dyslexia are opposite endpoints on a “continuum” of reading disability. . Patients with symptoms initially identical to a deep dyslexia diagnosis modified over time into symptoms more akin to a phonological dyslexia diagnosis. These observations suggest recovery is possible along the semantic pathway.

Connectionist Model
The Connectionist Model suggests that the phonological and semantic features are activated, but this activation decays at a rate too quick for cognitive processing, and errors are produced as a result of this fading activation. This hypothesis explains the broad symptom-complex of deep dyslexics without resorting to a multiple loci damage approach as seen in other models.

Treatment Options and Recovery
There have been many different studies done in an attempt to treat deep dyslexics, all which have been met with varying success. One method that has been frequently used is to teach patients to sound out words using grapheme-to-phoneme correspondence rules. Such methods are known as non-lexically based reading treatments. Other studies have looked at attempting to repair the semantic-lexical route, known as lexically based treatment. Regardless of the methodology, treatment studies with deep dyslexics are difficult because much of the information regarding this disability is still heavily debated. Treatment options may be successful on repairing one route of reading but not another, and success for one patient may not translate to success in another. Although there is no clear-cut approach to recovery for deep dyslexics, research is ongoing.