The role of visuospatial attention in developmental dyslexia: evidence from a rehabilitation study.

Shifting of visual attention induced by peripheral cues was studied in 24 children with specific reading disorder (SRD) or dyslexia and was compared with that of 19 normal readers by means of a covert orienting paradigm. This paradigm presents participants with valid, neutral and invalid spatial cues preceding the presentation of a target stimulus. As compared to normal readers, in SRD children the inhibition effect (i.e. the difference between neutral and invalid cues) was absent. The 24 SRD children were divided into two groups matched for age, IQ and reading ability to study the efficacy of two different rehabilitation procedures. We assessed the effects on reading accuracy and speed over a 4-month treatment with visual hemisphere specific stimulation (VHSS; J. Learn Disabil. 25 (1992) 102) vs. traditional speech training. The VHSS program trains participants to perform rapid endogenous attentional orienting by presenting briefly flashed words in the peripheral visual field. We found that children treated with VHSS showed significant changes in their attentional inhibition process, as indicated by increased costs for 'reorienting' the attentional focus. As this treatment program also proved to be highly efficient in improving the children's reading abilities, the possible causal relationship between reading and inhibition mechanisms of visuospatial attention was discussed.