Affiliations: [a] Department of Translational Research on New Technologies in Medicine and Surgery, School of Physical Medicine and Rehabilitation, University of Pisa, Pisa, Italy
| [b] Department of Clinical and Experimental Medicine, Cisanello Neurology Unit, Pisa University Medical School, Pisa, Italy
| [c] Unit of Environmental Epidemiology, Institute of Clinical Physiology, National Council of Research, Pisa, Italy
| [d] Children’s Neuropsychiatric Medical Facility, Local Health Authority of Viareggio (USL 12), Lido di Camaiore (LU), Italy
Correspondence:
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Corresponding author: Luca Bonfiglio, Department of Translational Research on New Technologies in Medicine and Surgery, School of Physical Medicine and Rehabilitation, University of Pisa, Via Roma 67, I-56126 Pisa, Italy. Tel./Fax: +39 050992655; E-mails: [email protected]; bubobis @gmail.com.
Abstract: Purpose: As well as obtaining confirmation of the magnocellular system involvement in developmental dyslexia (DD); the aim was primarily to search for a possible involvement of the parvocellular system; and, furthermore, to complete the assessment of the visual chromatic axis by also analysing the koniocellular system. Methods: Visual evoked potentials (VEPs) in response to achromatic stimuli with low luminance contrast and low spatial frequency, and isoluminant red/green and blue/yellow stimuli with high spatial frequency were recorded in 10 dyslexic children and 10 age- and sex-matched, healthy subjects. Results: Dyslexic children showed delayed VEPs to both achromatic stimuli (magnocellular-dorsal stream) and isoluminant red/green and blue/yellow stimuli (parvocellular-ventral and koniocellular streams). To our knowledge, this is the first time that a dysfunction of colour vision has been brought to light in an objective way (i.e., by means of electrophysiological methods) in children with DD. Conclusion: These results give rise to speculation concerning the need for a putative approach for promoting both learning how to read and/or improving existing reading skills of children with or at risk of DD. The working hypothesis would be to combine two integrated interventions in a single programme aimed at fostering the function of both the magnocellular and the parvocellular streams.
