Does the spelling dyslexic read by recognizing orally spelled words? An investigation of a letter-by-letter reader.
In this single case report we describe our further observations of a patient (ROC) with a classical spelling dyslexia. A word length effect and a script effect were demonstrated. No evidence of semantic processing was obtained with brief tachistoscopic presentations. Single letter identification was unimpaired. In a series of experiments it was shown that her letter-by-letter reading strategy was mediated by explicit letter naming. In particular, it was observed that with successive presentation of the individual letters there was a stepwise function relating her whole word reading to the single letter presentation times. These durations permitted explicit letter naming. When explicit letter naming was prevented by a simultaneous articulatory suppression task, her letter-by-letter reading was significantly impaired. Her performance was compared with a second patient (MRF) who could read but could not spell. His reading was unaffected by articulatory suppression and significantly impaired by a successive presentation of the individual letters of a word. It is argued that explicit letter naming provides an input to the spelling system and thus can be recognized as orally spelled words. We conclude that in the reading-impaired patient there was a lexical deficit compensated for by the operation of a component of her intact spelling system.
Dementia Research Group, Institute of Neurology, London and Royal Holloway, University of London, London, UK. e.warrington@dementia.ion.ucl.ac.uk
Elizabeth K
EK
Warrington
Dawn W
DW
Langdon
D004411:Dyslexia, Acquired / Q000209:etiology / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008959:Models, Neurological; D009483:Neuropsychological Tests; D010911:Pituitary Neoplasms / Q000150:complications / Q000601:surgery; D011183:Postoperative Complications / Q000523:psychology; D011597:Psychomotor Performance / Q000502:physiology; D011932:Reading; D013060:Speech / Q000502:physiology; D020521:Stroke / Q000523:psychology; D014796:Visual Perception