Why study coloured backgrounds and dyslexia?
Imagine struggling to write a shopping list or enjoy a good book! Unfortunately, completing these everyday tasks is a challenge for many people. In fact, roughly 15% of the nation (Moats & Dakin, 2020) suffers from a reading disability called neurodevelopmental dyslexia (an ironically complex name for a reading disorder I must note). Dyslexic individuals find it difficult to process particular sounds of a language, and so struggle to match printed letters to the relevant speech sounds (Law et al., 2014). Additionally, many dyslexic individuals also experience visual stress during reading, including the blurring of words and headaches (Wilkins, 2002). These cause dyslexics difficulty with reading and writing, making trivial tasks tiresome.
The most prominent dyslexia treatments focus on teaching dyslexics how to process sounds of a language and match them to printed letters (called phonics training; Snowling et al., 2020). Scientists, however, have developed an alternative, more appealing intervention – that comes in more colours than a bag of Skittles – in the form of coloured overlays and backgrounds. Overlays are transparent plastic sheets that can be placed over text, while coloured backgrounds are an online tool used to change screen background colours. They aim to decrease the sharp colour contrast between the text and the background, alleviating dyslexic individuals’ visual stress and enhancing their reading (Patel, 2020).
While numerous compelling testimonies (Crossbow Education, n.d.) proclaim the benefits of reading with coloured overlays and backgrounds, a recent meta-analysis by Galuschka et al. (2014) concluded that scientific evidence regarding their effectiveness is highly mixed and of poor quality. Despite this, coloured backgrounds and overlays continue to be used in schools, and six out of eight UK dyslexia charities still recommend them as a form of dyslexia intervention (Henderson et al., 2014). Moreover, Microsoft recently invested significant sums of money to develop coloured backgrounds in the Immersive Reader software, without a sound evidence base. As there is a need for high-quality evidence about the benefits of coloured backgrounds, we used eye-tracking to look at whether dyslexic and non-dyslexic individuals read sentences faster from a yellow compared to a white background. In consideration of previous findings, we predicted that reading from a yellow background will not benefit dyslexic individuals and, therefore, would not enhance their reading speed.
What did we do?
We recruited 29 dyslexic and 29 non-dyslexic individuals with a wide age range (18 to 45) from all educational levels. Firstly, participants completed various computer-based tasks used to measure their general language abilities. Then all participants read 128 sentences, half presented on a white and half on a yellow screen background, while their moment-to-moment eye movements were recorded. Each sentence contained either an uncommon or a common target word (e.g., ‘rapid’ versus ‘quick’). This allowed us to look at how long people took to read the whole sentence, as well as the hidden target word.
What did we find?
Our key finding was that reading from a yellow compared to a white background did not significantly improve either dyslexic or non-dyslexic participants’ target word and sentence reading speed. Thus, we concluded that yellow backgrounds do not benefit dyslexic individuals and should not be used as a dyslexia intervention tool.
We then compared dyslexic and non-dyslexic participants’ scores on the general language ability tasks. Dyslexics scored lower on these tasks, indicating that they certainly had a language deficit.
We also replicated the well-established finding that both dyslexic and non-dyslexic individuals take longer to read uncommon than common words. This is important, as reproducing findings that are agreed upon by scientists adds credibility to our novel findings about the highly debated topic of coloured background (in)effectiveness.
What are the implications of our findings?
Policy:
Based on our findings, organisations with a great influence on policy regarding dyslexia management, such as dyslexia charities, should stop advocating coloured backgrounds as a reliable dyslexia intervention.
Education:
Currently, several schools implement coloured backgrounds to help dyslexic students. However, our findings indicate that schools should prioritise the use of evidence-based remedial programmes for dyslexia, such as phonics training, over coloured backgrounds.
Technology:
Our results inform Microsoft’s Immersive Reader about the potential (in)effectiveness of their software, and also highlight that time and money should rather be invested in the development of treatments concerning phonology.
How did we improve on past research?
- Our study asked participants to read meaningful sentences, unlike other experiments that used lists of random words, which are far removed from real-life reading. Hence, our findings are more applicable to real-life reading scenarios.
- Our study used sophisticated eye-tracking technology to measure participants’ real-time sentence and target word reading. This provided us with a precise and comprehensive overview of how yellow backgrounds influence reading in dyslexia.
What could we do better next?
While we tested adults with a wide range of educational levels and reading experience, we did not recruit any children. This is a limitation, as we cannot make conclusions about how useful coloured backgrounds are for very young children, who are currently learning to read. Nevertheless, we can conclude that they don’t benefit those who already know how to read.
Additionally, while the colour yellow was carefully selected based on Stein’s (2014) suggestion of it being the most beneficial colour for dyslexics, our study only tested a single yellow background colour. Hence, we cannot comment on the benefits of using other coloured backgrounds, which limits our study. Future research should investigate if other colours are more beneficial for dyslexics than yellow appears to be.
References:
Crossbow Education. (n.d.) Visual Stress and coloured overlays. https://www.crossboweducation.com/dyslexia-coloured-overlays-and-visual-stressw backgrounds in treating dyslexia.
Galuschka, K., Ise, E., Krick, K., & Schulte-Körne, G. (2014). Effectiveness of treatment approaches for children and adolescents with reading disabilities: A meta-analysis of randomized controlled trials. PloS one, 9(2), e89900. https://doi.org/10.1371/journal.pone.0089900
Henderson, L. M., Taylor, R. H., Barrett, B., & Griffiths, P. G. (2014). Treating reading difficulties with colour. BMJ, 349. http://dx.doi.org/10.1136/bmj.g5160
Law, J. M., Vandermosten, M., Ghesquiere, P., & Wouters, J. (2014). The relationship of phonological ability, speech perception, and auditory perception in adults with dyslexia. Frontiers in human neuroscience, 8, 482. https://doi.org/10.3389/fnhum.2014.00482
Moats, L. C., & Dakin, K. E. (2020, March 10). Dyslexia basics. International Dyslexia Association. Retrieved September 21, 2021, from https://dyslexiaida.org/dyslexia-basics/.
Patel, D. (2020). Coloured overlays could help your child read better. Ocushield. https://www.ocushield.com/blogs/bluelight/coloured-overlays-could-help-your-child-read-better
Snowling, M. J., Hulme, C., & Nation, K. (2020). Defining and understanding dyslexia: past, present and future. Oxford Review of Education, 46(4), 501-513. https://doi.org/10.1080/03054985.2020.1765756
Stein, J. (2014). Dyslexia: the role of vision and visual attention. Current developmental disorders reports, 1(4), 267-280. https://doi.org/10.1007/s40474-014-0030-6
Wilkins, A. (2002). Coloured overlays and their effects on reading speed: a review. Ophthalmic and Physiological Optics, 22(5), 448-454. https://doi.org/10.1046/j.1475-1313.2002.00079.x