Patterns of peripheral paralexia: pure alexia and the forgotten visual dyslexia?
The concept of visual dyslexia put forward by Marshall and Newcombe (1973) is assessed. After a long period of neglect it was resurrected in the late 1990s in a narrow form. In the current paper it is proposed that a wider form of the functional syndrome is useful to include amongst other conditions attentional dyslexia and neglect dyslexia. The variety of sub-forms would correspond to the behavioural effects of the different ways in which the orthographic processing systems can be impaired. What distinguishes the broader form from pure alexia is that the patient lacks the capacity to use a serial letter processing strategy, and so interpretation of visual dyslexia in terms of the impairment to the orthographic processing systems is not contaminated by the use of a compensatory strategy that results in processing operations which are qualitatively very different from the normal and highly opaque. The lack of a serial letter processing strategy makes visual dyslexia a much more transparent functional syndrome.
Shallice
Tim
T
International School for Advanced Studies - SISSA-ISAS, Trieste, Italy. t.shallice@ucl.ac.uk
Rosazza
Cristina
C
D020237:Alexia, Pure / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D004411:Dyslexia, Acquired / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology; D006801:Humans; D008960:Models, Psychological; D010364:Pattern Recognition, Visual; D010468:Perceptual Disorders / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D011932:Reading; D012660:Semantics; D014796:Visual Perception