Which are the relations between lexical, attentional and perceptual processes in reading aloud?
Reading aloud involves several aspects, which are usually studied independently. At the ISTC the Reading and Lexical Processes Lab (W-Read) is investigating the relation between perceptual, attentional and lexical components in reading, with the purpose to shed a new light on some aspects of dyslexia, both developmental and acquired.
The simple operation of reading a single word requires many cognitive processes., and reading speed is limited by eye movements. At ISTC one goal of the W-Read group (Reading and Lexical Processes Lab) is to clarify how perceptual, attentional, and lexical components interact.
The relations between these components is investigated by studying unimpaired participants and neurological patients affected by neglect dyslexia (ND), a reading disorder often associated to the attentional disorder of unilateral spatial neglect (USN). In reading single words or nonwords, ND patients may misread letters, or groups of letters, that occupy the contralesional side of visual space. Usually the lesioned hemisphere is the right one, so that the unattended space results to be the left.
However, some patients read words better than non existing words (lexicality effect) and they differ with respect to the type of reading errors. Some patients may produce more letter substitution errors (the word "albero" read as "pobero") while others produce more omissions (the word "albero" read as "bero") always interesting the left-side of words. Some studies of the W-Read group have documented a relation between error type and the lexicality effects, suggesting that substitutions and omissions represent the two extremes of a single functional impairment, which manifests itself with different degrees of severity. Recently, the two error types have been proposed to reflect the disruption of two different mechanisms, a visuo-spatial mechanism (responsible for omissions) and a perceptual integration process (which would be responsible for substitution errors).
Finally, the recent use of eye's movements' recording in word reading, may help use to understand whether there is a relation between which letters the patient fixates and what he/she reports.
Contact: Cristina Burani
ISTC group: Reading and Lexical Processing Lab
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Vallar G, Burani C. & Arduino LS (2010). Neglect dyslexia: a review of the neuropsychological literature. Experimental Brain Research, 206, 219-235.