Everatt, John and Bradshaw, Mark F and Hibbard, Paul B (1999) Visual Processing and Dyslexia. Perception, 28 (2). pp. 243-254. DOI https://doi.org/10.1068/p2743
Everatt, John and Bradshaw, Mark F and Hibbard, Paul B (1999) Visual Processing and Dyslexia. Perception, 28 (2). pp. 243-254. DOI https://doi.org/10.1068/p2743
Everatt, John and Bradshaw, Mark F and Hibbard, Paul B (1999) Visual Processing and Dyslexia. Perception, 28 (2). pp. 243-254. DOI https://doi.org/10.1068/p2743
Abstract
<jats:p> Magnocellular-pathway deficits have been hypothesised to be responsible for the problems experienced by dyslexic individuals in reading. However, research has yet to provide a detailed account of the consequences of these deficits or to identify the behavioural link between them and reading disabilities. The aim of the present study was to determine the potential consequences of the magnocellular-pathway deficits for dyslexics in a comprehensive range of visual tasks. Dyslexics and nondyslexics were compared on their ability to (i) perform vernier-acuity and orientation-acuity tasks; (ii) perceive motion by using a range of measures common in the psychophysical literature ( D<jats:sub>min</jats:sub>, D<jats:sub>max</jats:sub>, and global coherence); and (iii) perceive shapes presented in random-dot stereograms at a range of disparity pedestals, thereby dissociating stereopsis from vergence control. The results indicated no significant differences in performance between the dyslexic and nondyslexic subjects in terms of the visual-acuity measures. In general, dyslexics performed relatively poorly on measures of motion perception and stereopsis, although when considered individually some of the dyslexics performed better than some of the controls. The poor performance of the dyslexics in the stereogram tasks was attributable to a subgroup of dyslexics who also appeared to have severe difficulty with the motion-coherence task. These data are consistent with previous evidence that some dyslexics may have deficits within the magnocellular visual pathway. </jats:p>
Item Type: | Article |
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Uncontrolled Keywords: | Visual Pathways; Humans; Dyslexia; Case-Control Studies; Depth Perception; Motion Perception; Psychophysics; Psychological Tests; Visual Acuity; Adolescent; Adult; Female; Male |
Subjects: | B Philosophy. Psychology. Religion > BF Psychology |
Divisions: | Faculty of Science and Health Faculty of Science and Health > Psychology, Department of |
SWORD Depositor: | Unnamed user with email elements@essex.ac.uk |
Depositing User: | Unnamed user with email elements@essex.ac.uk |
Date Deposited: | 13 Feb 2015 21:06 |
Last Modified: | 17 Sep 2024 06:57 |
URI: | http://repository.essex.ac.uk/id/eprint/12552 |
Available files
Filename: p2743.pdf