The journal Neurology features an interesting - and rather heartwarming - case report: "Teacher interrupted"
Authors Jason Cuomo et al, of Loyola University Chicago, write:
Reading to children was a source of fulfillment in the life of M.P., a 40-year-old aunt, kindergarten teacher, and reading specialist ... But all of that changed when, on a Thursday morning, she found herself standing at the front of her class and holding in her hands an indecipherable mystery. It was the attendance sheet. The same sheet she had used for years, and to hear M.P. tell it, it might as well have been covered in hieroglyphs.
She had suddenly and inexplicably lost the ability to read.
The school principal was as perplexed as she, and M.P. was promptly discharged from work and into the care of her mother.
Eventually, her mother took M.P. to hospital, where it was discovered that she had suffered a stroke. The stroke had caused a rare syndrome:
Alexia without agraphia, also commonly referred to as “word blindness,” in which patients lose the ability to read, but can still write and comprehend the spoken word... It was first described in 1892 by Joseph Jules Dejerine, who hypothesized that this unique pattern of deficits is caused by subcortical lesions that functionally isolate the left angular gyrus, or "language zone", from the visual cortex...
Determined to overcome her disability, M.P. tried to teach herself to read again, but despite her best efforts, she just could not recognize letters by sight. It was only when she hit upon the idea of feeling the shape of the symbols that she made progress:
To see this curious adaptation in practice is to witness the very unique and focal nature of her deficit. Given a word, M.P. will place her finger on the first letter and begin to trace each letter of the alphabet over it in order, until she recognizes that she has traced the letter she is looking at. "That is the letter M", she declares, after tracing the previous 12 letters of the alphabet with her finger while deciphering a word in front of her. Three letters later, she is able to shorten this exercise with a guess: "This word is ‘mother,’" she announces proudly.
Cuomo et al comment that "the language zone is robbed of its visual inputs but remains intact"; in essence, the finger-tracing routine is a way of getting information to that area by non-visual means. Strangely, however, the sight of some words provoke emotions in M.P., although she is not conscious of knowing the word meaning:
Nor are such intuitions uncommon for M.P. when looking at written words, for although she cannot read a word by sight, it may nevertheless elicit emotions that seem surprisingly appropriate. For instance, when shown the word "dessert" in writing, M.P. exclaimed, "Oooh, I like that!"
I find this dissociation between feeling words and understanding them the most remarkable part of this case. It suggests that either a) M.P.'s ability to decode writing is intact, on some subconscious level, which might require a revision to neuroscience of language textbooks, or b) words can elicit emotions by some kind of a conditioned association, requiring no understanding (or even power of understanding), which would have big implications for "subliminal messaging"
Cuomo J, Flaster M, & Biller J (2014). Right Brain: A reading specialist with alexia without agraphia: Teacher interrupted. Neurology, 82 (1) PMID: 24379102