Allographic agraphia for single letters.

The case is reported of a patient (PS) who, following acute encephalitis with residual occipito-temporal damage, showed a selective deficit in writing cursive letters in isolation, but no difficulty to write cursive-case words and non-words. Notably, he was able to recognize the same allographs he could not write and to produce both single letters and words in print. In addition to this selective single letter writing difficulty, the patient demonstrated an inability to correctly perform a series of imagery tasks for cursive letters. PS's performance may indicate that single letter production requires explicit imagery. Explicit imagery may not be required, instead, when letters have to be produced in the context of a word: letter production in this case may rely on implicit retrieval of well learned scripts in a procedural way.