ERIC Number: EJ952771
Record Type: Journal
Publication Date: 2011-Dec
Pages: 19
Abstractor: As Provided
ISBN: N/A
ISSN: ISSN-0096-1523
EISSN: N/A
Visual Temporal Processing in Dyslexia and the Magnocellular Deficit Theory: The Need for Speed?
McLean, Gregor M. T.; Stuart, Geoffrey W.; Coltheart, Veronika; Castles, Anne
Journal of Experimental Psychology: Human Perception and Performance, v37 n6 p1957-1975 Dec 2011
A controversial question in reading research is whether dyslexia is associated with impairments in the magnocellular system and, if so, how these low-level visual impairments might affect reading acquisition. This study used a novel chromatic flicker perception task to specifically explore "temporal" aspects of magnocellular functioning in 40 children with dyslexia and 42 age-matched controls (aged 7-11). The relationship between magnocellular temporal resolution and higher-level aspects of visual temporal processing including inspection time, single and dual-target (attentional blink) RSVP performance, go/no-go reaction time, and rapid naming was also assessed. The Dyslexia group exhibited significant deficits in magnocellular temporal resolution compared with controls, but the two groups did not differ in parvocellular temporal resolution. Despite the significant group differences, associations between magnocellular temporal resolution and reading ability were relatively weak, and links between low-level temporal resolution and reading ability did not appear specific to the magnocellular system. Factor analyses revealed that a collective "Perceptual Speed" factor, involving both low-level and higher-level visual temporal processing measures, accounted for unique variance in reading ability independently of phonological processing, rapid naming, and general ability. (Contains 8 footnotes, 7 tables, and 5 figures.)
Descriptors: Reaction Time, Reading Research, Visual Impairments, Dyslexia, Reading Ability, Children, Foreign Countries, Elementary Schools
American Psychological Association. Journals Department, 750 First Street NE, Washington, DC 20002-4242. Tel: 800-374-2721; Tel: 202-336-5510; Fax: 202-336-5502; e-mail: order@apa.org; Web site: http://www.apa.org/publications
Publication Type: Journal Articles; Reports - Research
Education Level: Elementary Education
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A
Identifiers - Location: Australia
Identifiers - Assessments and Surveys: Wechsler Individual Achievement Test
Grant or Contract Numbers: N/A