title: Defective chromatic and achromatic visual pathways in developmental dyslexia: Cues for an integrated intervention programme.
abstract: 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.
  
  
  
  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.
  
  
  
  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.
  
  
  
  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.
authors.affiliation: Department of Translational Research on New Technologies in Medicine and Surgery, School of Physical Medicine and Rehabilitation, University of Pisa, Pisa, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Bonfiglio
authors.affiliation: Department of Clinical and Experimental Medicine, Cisanello Neurology Unit, Pisa University Medical School, Pisa, Italy.
authors.forename: Tommaso
authors.initials: T
authors.lastname: Bocci
authors.affiliation: Unit of Environmental Epidemiology, Institute of Clinical Physiology, National Council of Research, Pisa, Italy.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Minichilli
authors.affiliation: Department of Translational Research on New Technologies in Medicine and Surgery, School of Physical Medicine and Rehabilitation, University of Pisa, Pisa, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Crecchi
authors.affiliation: Department of Clinical and Experimental Medicine, Cisanello Neurology Unit, Pisa University Medical School, Pisa, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Barloscio
authors.affiliation: Children's Neuropsychiatric Medical Facility, Local Health Authority of Viareggio (USL 12), Lido di Camaiore (LU), Italy.
authors.forename: Donata Maria
authors.initials: DM
authors.lastname: Spina
authors.affiliation: Department of Translational Research on New Technologies in Medicine and Surgery, School of Physical Medicine and Rehabilitation, University of Pisa, Pisa, Italy.
authors.forename: Bruno
authors.initials: B
authors.lastname: Rossi
authors.affiliation: Department of Clinical and Experimental Medicine, Cisanello Neurology Unit, Pisa University Medical School, Pisa, Italy.
authors.forename: Ferdinando
authors.initials: F
authors.lastname: Sartucci
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D002648:Child; D003118:Color Perception / Q000502:physiology*; D015350:Contrast Sensitivity / Q000502:physiology*; D003463:Cues; D004410:Dyslexia / Q000534:rehabilitation*; D004569:Electroencephalography; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D010775:Photic Stimulation; D014795:Visual Pathways / Q000502:physiology*
keywords: Reading disorder; VEPs; chromatic contrast; koniocellular; letter recognition; luminance contrast; magnocellular; parvocellular