Allographic agraphia: a case study.
We report the case of patient MN, diagnosed with frontotemporal dementia, who exhibited a severe impairment in writing letters and words in upper-case print in the face of accurate production of the same stimuli in lower-case cursive. In contrast to her written production difficulties, MN was unimpaired in recognizing visually presented letters and words in upper-case print. We find a modest benefit of visual form cueing in the written production of upper-case letters, despite an inability to describe or report visual features of letters in any case or font. This case increases our understanding of the allographic level of letter-shape representation in written language production. It provides strong support for previous reports indicating the neural independence of different types of case and font-specific letter-shape information; it provides evidence that letter-shape production does not require explicit access to information about the visual attributes of letter shapes and, finally, it reveals the possibility of interaction between processes involved in letter-shape production and perception.
Menichelli
Alina
A
Department of Psychology, University of Trieste, Trieste, Italy.
Rapp
Brenda
B
Semenza
Carlo
C
D000369:Aged, 80 and over; D000381:Agraphia / Q000150:complications* / Q000175:diagnosis; D003704:Dementia / Q000150:complications* / Q000175:diagnosis; D005260:Female; D006236:Handwriting; D006801:Humans; D010364:Pattern Recognition, Visual; D011597:Psychomotor Performance; D011930:Reaction Time