alexia

n. Pure alexia is a form of acquired word blindness in which writing and spelling can be unaffected (i.e., alexia without agraphia). Single-letter recognition is usually intact, and comprehension and production of spoken
language are normal, allowing patients to use an oral spelling strategy to recognise written words (e.g., cap = C, A, P). A striking feature of pure alexia is that patients are unable to read aloud words they have themselves just written. Patients appear to decode words as a sequence of isolated letters without any access to holistic word recognition processes that are used by the normal reader. Letter-by-letter reading appears to arise from a disconnection that prevents the parallel mapping of abstract letter identities onto word level representations so that access to word forms is sequential. Reading of words and nonwords is slow, and reading time is a linear function of the number of letters in a letter string. Pure alexia often resolves rapidly after brain injury. Rehabilitation involves using intact reading mechanisms in the right hemisphere. - BW