Visually- and motor-based knowledge of letters: evidence from a pure alexic patient

Bartolomeo, Paolo; Bachoud‐Lévi, Anne‐Catherine; Chokron, Sylvie; Degos, Jean‐Denis

doi:10.1016/s0028-3932(01)00209-3

Cited by 75 publications

(56 citation statements)

References 58 publications

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“…Patient C.Z. was excellent in tasks of mental imagery involving letter shapes, an ability to which the VWFA possibly contributed (for an opposite case see Bartolomeo, Bachoud-Levi, Chokron, & Degos, 2002). There is also evidence that infero-temporal regions can receive top-down activation by auditory words, whenever orthographic processing is required.…”

Section: Role Of Residual Left Fusiform Activationsmentioning

confidence: 97%

The pathophysiology of letter-by-letter reading

et al. 2004

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Pure alexia is a frequent and incapacitating consequence of left occipitotemporal lesions. It is thought to result from the disruption or the disconnection of the visual word form area (VWFA), a region reproducibly located within the left occipito-temporal sulcus, and encoding the abstract identity of strings of visual letters. Alexic patients often retain effective single letter recognition abilities, and develop an effortful letter-by-letter reading strategy which is the basis of most rehabilitation techniques. We study a patient who developed letter-by-letter reading following the surgical removal of left occipito-temporal regions. Using anatomical and functional MRI in the patient and in normal controls, we show that alexia resulted from the deafferentation of left fusiform cortex, and we analyze the network of brain regions subtending letter-by-letter reading. We propose that during letter-by-letter reading (1) letters are identified in the intact right-hemispheric visual system, with a central role for the region symetrical to the VWFA; (2) letters are serially transferred to the left hemisphere through the intact segment of the corpus callosum; (3) word identity is eventually recovered in the left hemisphere through verbal working memory processes involving inferior frontal and supramarginal cortex.

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Section: Role Of Residual Left Fusiform Activationsmentioning

confidence: 97%

The pathophysiology of letter-by-letter reading

et al. 2004

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“…VA was first asked to recall from memory whether letters spoken by the examiner contained any curved lines in their uppercase format (Bartolomeo, Bachoud-Lévi, Chokron, & Degos, 2002). She was then asked to recall from memory whether letters in their lower case format contained an ascender (e.g., b), a descender (e.g., g) or neither (e.g., m).…”

Section: Letter Imagerymentioning

confidence: 99%

Covert reading of letters in a case of global alexia

et al. 2012

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We would like to dedicate this work to the memory of Lamberto Piron Keywords:Global alexia Abstract letter identification Right hemisphere contribution to word reading a b s t r a c t This study describes the case of a global alexic patient with a severe reading deficit affecting words, letters and Arabic numbers, following a left posterior lesion. The patient (VA) could not match spoken letters to their graphic form. A preserved ability to recognize shape and canonical orientation of letters indicates intact access to the representation of letters and numbers as visual objects. A relatively preserved ability to match lowercase to uppercase letters suggests partially spared access to abstract letter identities independently of their visual forms. The patient was also unable to match spoken letters and numbers to their visual form, indicating that she could not access the graphemic representations of letters from their phonological representations. This pattern of performance suggests that the link between graphemic and phonological representations is disrupted in this patient. We hypothesize that VA' residual reading abilities are supported by the right hemisphere.

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“…In the area of handwriting, Bartolomeo, Bachoud-Lévi, Chokron, and Degos (2002) have shown that the action of tracing the shape of a letter with a finger can help alexic patients identify the letter presented visually. Recent studies using neuroimaging techniques validate this link between the visual and motor shapes of letters (Longcamp, Anton, Roth, & Velay, 2003;Longcamp, Tanskanen, & Hari, 2006).…”

Section: Introductionmentioning

confidence: 99%