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Updated: Jul 4, 2026

Training Synesthetic Letter-color Associations by Reading in Color
Published on: February 20, 2014
Coloured filters and reading accuracy, comprehension and rate: a placebo-controlled study
C Mitchell1, D Mansfield, S Rautenbach
1School of Psychology, University of KwaZulu Natal, Pietermaritzburg, Private Bag X01, Scottsville, 3209 South Africa. mitchellc@ukzn.ac.za
Abstract:
Literature suggests that visuoperceptual deficits not normally assessed by eye examinations may be responsible for certain reading disabilities. Previous studies indicate that the use of nonoptical coloured filters may reduce these deficits and improve reading performance. Present research involved 49 participants with visuo-perceptual reading disabilities. Participants were divided into a control group who received no intervention, a placebo group who received filters in a colour complementary to the individual's optimal colour, and an experimental group who received specifically matched coloured filters. At posttest the experimental group reported statistically significantly fewer visual discomfort symptoms. The remainder of the results were, however, inconsistent. Some potential explanations are explored.
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