1/3. Letters lost in space: hemispace dependent handwriting errors.Although handwriting is a daily life activity commonly attributed to the left hemisphere in the majority of right-handers, it is also known to require attentional and spatial mechanisms that rely on right hemispheric processing. The underlying spatial organization of handwriting in patients with right brain damage remains unresolved. Here we show in a patient with circumscribed right superior parietal damage that handwriting systematically depends on the hand's position in space with respect to her body-midline. Most importantly, handwriting in contralesional space not only leads to spatial but also to language errors. This suggests that the right hemisphere's role in handwriting may surpass its generally assumed purely spatial contribution. We discuss our results in term of co-registration between both cerebral hemispheres in language processing.- - - - - - - - - - ranking = 1keywords = handwriting (Clic here for more details about this article) |
2/3. Left non-dominant hand mirror writing.A 38-year-old right-handed woman, who had suffered a left cerebral hemisphere infarction, was studied. She developed right hemiparesis, motor and sensory aphasia, and left hand mirror writing. All possible brain mechanisms involved in writing, either perceptual or motor, were investigated in search of the one responsible for her mirror writing; however, no abnormality was detected. On examination of the left handwriting, in the directionality of writing tracings as related to the body midline, we detected a lack of inversion of the right handwriting motor patterns--at the moment they are transmitted from the left to the right cerebral hemisphere--implicating a motor rather than a perceptual mechanism.- - - - - - - - - - ranking = 0.22222222222222keywords = handwriting (Clic here for more details about this article) |
3/3. Acquired dysgraphia in alphabetic and stenographic handwriting.We report the unusual case of AZO, who professionally used handwritten shorthand writing, and became dysgraphic after a stroke. AZO suffered from a complex cognitive impairment, and part of her spelling errors resulted from damage to auditory input processing, to phonology-orthography conversion procedures and to the ortographic output lexicon. However, analysis of her writing performance showed that the same variables affected response accuracy in alphabetic and shorthand writing; and, that the same error types, including transpositions, were observed in all tasks in the two types of writing. These observations are consistent with damage to the graphemic buffer. They suggest that, in multiple-code writing systems (e.g., stenography, Japanese, or in the case of multilingual speakers of languages that use different spelling codes), the graphemic buffer is shared by all codes.- - - - - - - - - - ranking = 0.44444444444444keywords = handwriting (Clic here for more details about this article) |