Citation distortion

Greenberg SA. How citation distortions create unfounded authority: analysis of a citation network. BMJ. 2009;339:b2680. pubmed link 

I wish I could say that I read this paper when it was published in the British Medical Journal in 2009. I did not; in fact, I didn't even notice it at the time. I reached it about five years too late through Ben Goldacre's book I -Think You'll Find It's a Bit More Complicated Than That - which is a collection of his columns from the Guardian.  The chapter -How Myths are Made - page 47 -  highlights this landmark paper that shows that, even in 'respectable' academic circles, examples of sharp practice can still be found. 
In a scientific paper, each claim is supported by a citation to another scientific paper or review that supports the argument being made. Citation should be an impartial and scholarly method of communication.
Stephen Greenberg showed how a false belief system could be spread through the scientific literature by bias against papers that do not support the argument and by amplification and distortion of papers that support the argument. He detailed some specific problems in the literature and categorised the types of distortions he encountered, in relation to a hypothesis that was ultimately shown to be false. 

Types of citation distortion

He went further, however, and demonstrated by network analysis that supportive citation paths can produce chains of false claim in the network. A small number of review papers acted as gateways focussing large amounts of traffic and shone a light on some papers whilst leaving others in the shadows.
The end result was the conversion of a hypothesis to fact by citation alone.
There was no random or haphazard pattern to the distortions found in the network such as might have arisen by chance or random drift. Instead, Greenberg found, as Ben Goldacre puts it, 'a web of systematic self-reinforcing distortion resulting in the creation of a myth'

So, is this any of this relevance to the treatment of visual stress with colour?
In my opinion, the citation network surrounding the treatment of visual stress has been distorted in a similar manner and some day, when I have little more time, I plan to conduct a similar exercise to that conducted by Stephen Greenberg for the B amyloid hypothesis. I suspect there will be three or four individuals who have succeeded in distorting the research network to create unfounded authority for the claim that the treatment of visual stress with colour can aid reading.
In the meantime here are some examples of what I am talking about.

Citation transmutation - conversion of hypothesis into fact by citation alone -
Randomized controlled trials support the existence of MIS- ViS (Wilkins et al. 1994; Robinson and Foreman 1999) This quote comes from a paper of which Arnold Wilkins is the senior author looking at fMRI findings on one patient(1). However, the references cited in this line from the conclusion section do not support the claim that -RCTs support the existence of MIS-ViS -both of these studies were negative and showed no improvement in reading compared to a placebo control group. See Holy Trinity 1 and Holy Trinity 3.

Dead end citation -support of a claim with citation to papers that do not contain content addressing the claim -
This example comes from a paper by John Stein's group in Oxford(2) It was felt ethically unjustified to use a control group in the design as no benefit had been achieved with placebo filters during independent trials of these types of filters (21,22). Reference 22 which they cite in support of this claim did not actually contain a placebo control group(3).

Citation bias - Ignoring papers that do not support the argument- 
Going back to the same quote, that is was ethically unjustified to use a placebo control group. The authors ignore three studies that show as much improvement in the placebo control group as the experimental tint group (4,5,6)

The net effect of all this is that a vague hypothesis to account for reading difficulties has been transmuted into accepted scientific dogma. Furthermore, what are at best conflicting results from treatment trials have been presented as proof of an effective treatment. This is more than academic pedantry. This costs parents money and wastes children's valuable time.

1.         Chouinard BD, Zhou CI, Hrybouski S, Kim ES, Cummine J. A Functional Neuroimaging Case Study of Meares–Irlen Syndrome/Visual Stress (MISViS). Brain Topogr. 2012 Jul;25(3):293–307.

2.         Harries P, Hall R, Ray N, Stein J. Using coloured filters to reduce the symptoms of visual stress in children with reading delay. Scand J Occup Ther. 2015 Mar;22(2):153–60.

3.         Hall R, Ray N, Harries P, Stein J. A comparison of two-coloured filter systems for treating visual reading difficulties. Disabil Rehabil. 2013 Apr 29;35:2221–6.

4.         Wilkins AJ, Evans BJ, Brown JA, Busby AE, Wingfield AE, Jeanes RJ, et al. Double-masked placebo-controlled trial of precision spectral filters in children who use coloured overlays. Ophthalmic Physiol Opt J Br Coll Ophthalmic Opt Optom. 1994 Oct;14(4):365–70.

5.         Robinson GL, Foreman PJ. Scotopic sensitivity/Irlen syndrome and the use of coloured filters: a long-term placebo controlled and masked study of reading achievement and perception of ability. Percept Mot Skills. 1999 Aug;89(1):83–113.

6.         Ritchie SJ, Della Sala S, McIntosh RD. Irlen colored overlays do not alleviate reading difficulties. Pediatrics. 2011 Oct;128(4):e932–938.