Alexia
From Psy3242
Contents |
What Is It?
Alexia is an inability to read. It was first described by French neurologist Dejerine in 1892. He had a patient.
Acquired Versus Pure
Acquired Alexia occurs after brain damage. It is sometimes associated with agraphia, which is the inability to write; however, they two can occur separately.
Pure Alexia is a form of Dyslexia in which patients do not read with a fast pace for word recognition. Usually the longer the word is, the longer it takes the patient to recognize what the word is. The damage in the brain occurs during development. Oddly, pure Alexia usually occurs in a patient with no impaired language or writing skills, and patients have no problem labeling objects. Spelling is intact in these patients, as well as comprehension, speech, production and writing; however, they struggle to read what they have written.
What Part of the Brain is Effected
Alexia without agraphia often occurs in the posterior part of the Corpus Callosum and Occipital Lobe, where lesions have formed after brain damage. These patients cannot read because the words in the left visual field transfer over to the right hemisphere, but because of the damage to the Corpus Callosum, the information cannot be transferred back over for comprehension. This can be referred to as a Disconnection Syndrome.
