C37672: Coloured lenses and cognitive function

Closing Date: 19/09/2014

Communication Ocular disease Communication Ocular abnormalities

A basic explanation for many of the characteristic cognitive behaviours of individuals with autism and Asperger syndrome is that processing pathways in the brain differ from that of ‘normal’ individuals as described by Gomot and Wicker.1 It is also identified that this imbalance of cognitive function of individuals with autism and Asperger syndrome is significantly associated with processing of visual images and where the imperfect processing of such images can lead to distress and anxiety.

While this form of visual dysfunction can trigger a wide range of developmental challenges, one key manifestation of this visual processing dysfunction is the condition known as prosopagnosia – or ‘face blindness’2 – where individuals lack the ability to visually process facial information. This inability to recognise faces can readily give rise to an aversion to social interaction. This condition of prosopagnosia can manifest as an isolated symptom within an individual with ‘normal’ cognitive function or it can co-exist within a range of other cognitive issues and, for example, is often identified in individuals diagnosed with autism or Asperger syndrome. The manifestation of prosopagnosia through direct neurological factors such as physical trauma is thought to be linked with impairment of a function of the right fusiform gyrus as described by Barton et al.3

The availability of functional magnetic resonance imaging (fMRI)4 has become a key tool for research into cognitive function, where regions of higher neuronal activity are detected by increased levels of blood flow and tissue oxygenation. McCarthy et al5 have used this technique to investigate the relative activity of brain regions when subjects are presented with a range of visual image stimuli. Such studies show that while the right fusiform region can be stimulated by a range of images, there is typically a smaller region within the right lateral fusiform gyrus which is uniquely associated with presentation of facial images. Hadjikhani et al6 have used fMRI to demonstrate that subjects with autism spectrum disorder have normal fusiform gyrus function, suggesting that dysfunction in facial recognition may be associated with more complex cognitive interactions.

Research has been undertaken to determine the effect of coloured filters on the ability of individuals to process visual information. A number of systems7,8 for prescribing visual filters to improve visual functioning have been developed, although the subject area has become something of a fault line between sceptical academics, practitioners providing solutions and the parents of children seeking help with challenging behaviours.

Some work has been undertaken to investigate the basic aspects of use of coloured filters to compensate for aspects of colour vision deficiency in the absence of components of cognitive impairment. Swarbrick et al9 describe the relevance of the ChromaGen contact lens system for alleviation of colour vision deficiency among a study of 14 subjects. While there was some evidence of an enhancement of colour perception, the system could not be recommended for colour vision deficiency within an occupational setting. Simunovic10 also describes how colour vision deficiency is linked with genetic defects within photoreceptors and also identify that specific visual aids do not significantly help to obtain normal colour discrimination.

MRI brain scan: imperfect processing of visual images in the autistic individual can lead to distress and anxiety

MRI brain scan: imperfect processing of visual images in the autistic individual can lead to distress and anxiety

Visual filters: effect on reading speeds for children with autistic spectrum disorders

A specific study by Ludlow et al,11 however, involving a control group of 19 children and a matched set of children with autistic spectrum disorders, indicated a significant improvement in reading speed in the group of autistic children with the use of colour overlays. The specific set of such overlays were described as ‘Intuitive Coloured Overlays’ and were developed by Professor Arnold Wilkins of the Visual Perception Unit at Essex University (Wilkins et al).12 The series of nine hues are designed in CIE uv colour space to have equivalent saturations and allow a large range of colours as combinations of one or more overlays. Within the group of autistic children it was identified that 15 out of 19 subjects obtained at least a 5 per cent improvement in reading speed while for the control group the equivalent figure was three out of 19. The ‘methods’ description of the study, however, indicates the complexities and difficulties of undertaking research in this field. Numerous studies such as that of Bouldoukia

n et al13 have also indicated benefits of use of colour overlays to improve reading rates of individuals with learning difficulties. It should also be indicated, however, that there are studies and reports such as that of Ritchie et al14 which claim to demonstrate that the use of Irlen overlays provides no benefit to subjects within the normal school environment with subjects identified by Irlen specialist diagnosticians as having a reading deficit. By contrast, Noble et al15 demonstrate the significant benefits of coloured overlays in reading skills within two elementary school environments.

autism-signs

Visual filters: the connection with social interaction

There have been many claims of the value of visual filters in the improvement of social interaction of autistic subjects, but this has been largely based on anecdotal evidence. The recent work by Ludlow et al,16 however, provides some measure of confirmation of the potential ability of visual filters to modify such responses, although it is by no means a validation of all approaches currently in the public domain which utilise visual filters.

Within autistic studies, the development of the ‘Reading the Mind in the Eyes’ test by Baron-Cohen et al17 has proved a key method of identifying adults with Asperger syndrome or high-functioning autism. The test has subsequently been refined18 to improve its diagnostic sensitivity and thus provides a useful experimental technique for studies involving assessment of visual processing skills. This test was subsequently used by Ludlow et al16 to assess the effect of colour overlays (Intuitive Overlays) in undertaking the ‘Reading the Mind in the Eyes’ test. In the test a set of 28 images, each with four key words to identify the emotion being portrayed in the image of the eye, was split into two sets of 14 and with the 15 subjects being randomly assigned to sets of 14 tests with or without the use of coloured overlays. A significant finding was that 11/15 (73 per cent) of the children with autism were able to identify more faces with specific emotional states by using an overlay, compared with only 4/15 (27 per cent) of subjects from the control group. The use of the overlay was therefore allowing a latent cognitive function to act more successfully.

Some techniques (such as ‘orthoscopics’) have been developed that, anecdotally, have reported a benefit in the way a patient is able to identify faces.19,20,21 As yet there are no published evidence-based studies regarding such techniques. The natural tendency of an individual experiencing an autistic condition is to withdraw into a world of minimal social interaction, and develop compensating behavioural mannerisms which in turn become the focus of behaviour modification strategies. Non-verbal patients on the autistic spectrum present specific challenges as part of this diagnostic process. The observation of some degree of ‘recovery’ of recognition of facial features in autistic subjects with the use of visual filters would suggest that the sensory system responsible for facial recognition in these subjects may be working inefficiently rather than permanently impaired. This confirms the observations of Hadjikhani et al.6

Visual pictorial cards aid communication with children on the autism spectrum, by illustrating what will happen

Visual pictorial cards aid communication with children on the autism spectrum, by illustrating what will happen

Colour filter therapy and synaesthesia

Individual manifest symptoms of synaesthesia22,23 (a cognitive condition where there is cross-over between sensory channels) may also benefit from colour filter therapy. Various research groups, such as those at Sussex University and Edinburgh University, have a specific research focus investigating synaesthesia. This is primarily to investigate the condition within the higher functioning ‘normal’ population such as the study by Banissy et al24 which reviews issues over personality types of individuals manifesting the condition. There is also a focus on understanding the presentation of synaesthesia within creative individuals as described by Rothen and Meier.25 In this context, synaesthesia can be considered an enrichment of the sensory condition, although for extreme manifestations of autism it can be a life-limiting condition, as for example where general sensory input causes sensory confusion. As yet, however, these research groups have not investigated the potential interaction of colour overlays or lenses to modify the presentation of synaesthesia.

Studies, such as that of Hupe et al,26 have used fMRI techniques to investigate the characteristics of cognitive function with synaesthetic colours (triggered by graphemes). Initial observations indicate that false colour generation due to synaesthesia was not observed to generate any significant brain activity within conventional colour centres of the visual system. A recent study by Baron-Cohen et al27 detected some form of synaesthesia in adults with autism at a level of around 19 per cent, while the corresponding value for the control group was around 7 per cent. The content of social media forums in this area contains several accounts of individuals where the use of coloured lenses impacts significantly across the other major senses.28

Tinted lenses from Cerium Visual Technologies

Tinted lenses from Cerium Visual Technologies

Magnetocellular system theory

Professor Stein of Oxford University has extensively researched the so-called magnetocellular system,29 which is associated with co-ordinating movements of the eye generally within visual function and specifically in the process of reading. Significant work has been undertaken in linking various levels of dyslexia to sub-optimal functioning of this magnetocellular system and where it is postulated that this condition is associated with impaired development of the relevant cell line. The importance of the magnetocellular system is in co-ordinating reading function as has also been described by Bucci et al.30 It is also considered that impaired magnetocellular development may be a contributing factor in a wide range of conditions including those on the autistic spectrum.31 It is considered that yellow light, which stimulates both red and green photoreceptors, can preferentially activate the magnetocellular system and benefits have been observed, for example, in the use of yellow lenses to treat dyslexic children.32,33,34 In addition, it was demonstrated that monocular occlusion was associated with enhanced reading development within a study of children supplied with yellow reading lenses.35 There is also an identified benefit with blue light which regulates the activity of the hypothalamus and where it is thought that the functioning of the magnetocellular system is enhanced with specific stimulation of this ‘body clock’ function.36

Developing the research focus

It has long been recognised that autistic individuals typically experience higher levels of stress due to difficulties encountered in interactions with their environment. While ‘normal’ subjects are typically able to describe levels of stress relating to their experiences, this can be a key weakness for any research involving identification of stress levels with autistic subjects. Tordjman et al37 have, however, identified raised levels of beta-endorphin (BE) and adrenocorticotropin hormone (ACTH) within a set of 48 autistic individuals. No elevation of levels of cortisol, was, however, observed. Control groups included mentally/cognitively impaired individuals and a group of normal individuals. These hormones are considered markers of acute stress response and it is proposed that the individuals demonstrating severe autism are likely to have an emphasised response to acute stress factors.

It is relevant to note that Curin et al38 report higher levels of adrenocorticotropin (ACTH) but lower levels of cortisol within 36 autistic and 27 control subjects, but do not associate the raised levels of ACTH with accentuated response to stress factors. The study of Iwata et al39 confirms the elevation of levels of adrenocorticotropin (ACTH) within a set of 32 male autistic subjects with comparison of a control group of 34 normal subjects. Care was taken in the study to exclude any subjects on anti-psychotic and anti-epileptic medications since evidence has been identified that such medication can alter the balance of anterior pituitary hormones.40

While it is more challenging to obtain objective responses from individuals with severe autism in studies identifying the value of visual filters (such as used within ‘orthoscopics’), it would be possible to try to demonstrate effects that could be identified in levels of beta-endorphin (BE) and adrenocorticotropin hormone (ACTH) within appropriate subject and control groups.

Key points about autistic spectrum disorder

? Two separate conditions exhibiting obsessive and repetitive behaviour along with communication and interaction difficulties were originally described – autism (by Leo Kenner) and Asperger syndrome (by Hans Asperger)

? Clinicians, in observance of the sometimes unclear boundaries between the conditions and the range of exhibited traits, now describe a spectrum of disease known as autistic spectrum disorder (ASD)

? Common to all ASD individuals, although in very varied proportions and levels of severity, are three main characteristics: language and communication difficulties, poor reciprocal social interaction, and repetitive stereotyped behaviours usually seen alongside an absence of creative play

? The triad of social impairment, poor language and a lack of imaginative play may be recognised in children at the age of two years but, owing to the differences in the severity of these signs, may be overlooked and a child may not be diagnosed until later in life

? The classification of ASD has been revised, with the proposed revisions for the diagnostic and Statistical Manual of Mental Disorders (DSM-5) published in May 2013. The early detection of ASD in young children is important because early intervention by speech and language therapists, occupational therapists, and the introduction of social stories to reinforce behaviour all help the child develop the areas where he/she may be lacking. The optometrist can play an important role in noticing possible behavioural differences in these young children

? ASD is a lifelong developmental condition whose prevalence is increasing owing to greater awareness rather than any single causative agent

? Studies of prevalence vary but typical values for ASD are 38 to 40 per 10,000

? Currently there is no single aetiological factor that can account for ASD. Several candidate genes have been linked and associated with ASD; however, the complexity of the polymorphisms and the functional roles each may play in cortical development have yet to be fully elucidated

? Using images to explain the eye test protocols, and giving the patient time to listen and respond to any questions will help. Cycloplegia would need to be discussed carefully with the parent, as the onset of blur is likely to cause distress to the child

? In colour discrimination using the 100 Hue test, ASD individuals make a greater number of errors, although the errors did not follow a red-green or blue-yellow axis16

? However, static contrast sensitivity thresholds and visual acuity are normal in ASD, and studies have found little difference with regard to binocular status

? When examining a child with ASD, speech and language must be direct and simple with no complex sentences requiring multiple actions from the child

? The ASD child may object to being occluded, wearing trial frames and repeat the last phrase spoken to him/her which will hinder a subjective refraction

Summary

Those involved in the care of autistic children and adults know only too well the often overwhelming difficulties associated with their care and management. This drives a sense of extreme urgency to develop and verify innovative methods of care which will make a real difference to the lives of all those affected. The use of coloured lenses is an example of a promising technology which identifies a broad (and very obvious) range of scientific investigations to confirm both its effectiveness as a therapy and also the effect of optical filters on general cognitive function.

References

1 Gomot M, Wicker B. A challenging, unpredictable world for people with autism spectrum disorder. Int J Psychophysiol, 2012; 83,240-7.

2 Dalrymple KA, Fletcher K, Corrow S, et al. ‘A room full of strangers every day’: The psychosocial impact of developmental prosopagnosia on children and their families. 1. J Psychosom Res, 2014;77, 144-50.

3 Barton JJ, Press DZ, Keenan JP, O’Connor M. Lesions of the fusiform face area impair perception of facial configuration in prosopagnosia. Neurology, 2002; 58,71-8.

4 Matthews PM, Jezzard P. Functional magnetic resonance imaging. J Neurol Neurosurg Psychiatry, 2004;75,6-12.

5 McCarthy G, Puce A, Gore JC, Allison T. Face-specific processing in the human fusiform gyrus. J Cogn Neurosci, 1997; 9,605-10.

6 Hadjikhani N, Joseph RM, Snyder J, et al. Activation of the fusiform gyrus when individuals with autism spectrum disorder view faces. Neuroimage, 2004;22,1141-50.

7 Robinson GL, Conway RN. Irlen filters and reading strategies: effect of coloured filters on reading achievement, specific reading strategies, and perception of ability. Percept Mot Skills, 1994;79,467-83.

8 Wilkins AJ, Evans BJ, Brown JA, et al. Double-masked placebo-controlled trial of precision spectral filters in children who use coloured overlays. Ophthalmic Physiol Opt, 1994;14,365-70.

9 Swarbrick HA, Nguyen P, Nguyen T, Pham P. The ChromaGen contact lens system: colour vision test results and subjective responses. Ophthalmic Physiol Opt, 2001;21,182-96.

10 Simunovic MP. Colour vision deficiency. Eye (Lond), 2010;24,747-55.

11 Ludlow AK, Wilkins AJ, Heaton P. The effect of coloured overlays on reading ability in children with autism. J Autism Dev Disord, 2006;36,507-16.

12 Wilkins AJ, Nimmo-Smith MI & Jansons J. A colorimeter for the intuitive manipulation of hue and saturation, and its application in the study of perceptual distortion. Ophthalmic and Physiological Optics, 1992;12, 381-385.

13 Bouldoukian J, Wilkins AJ, Evans BJ. Randomised controlled trial of the effect of coloured overlays on the rate of reading of people with specific learning difficulties. Ophthalmic Physiol Opt, 2002;22, 55-60.

14 Ritchie SJ, Della Sala S, McIntosh RD. Irlen colored overlays do not alleviate reading difficulties. Pediatrics, 2011;128(4):e932-8.

15 Noble J, Orton M, Irlen S & Robinson G. A controlled field study of the use of coloured overlays on reading achievement. Australian Journal of Learning Disabilities, 2004;9, 14-22.

16 Ludlow AK, Taylor-Whiffen E, Wilkins AJ. Coloured filters enhance the visual perception of social cues in children with autism spectrum disorders. ISRN Neurol, 2012;2012:298098. doi: 10.5402/2012/298098.

17 Baron-Cohen S, Wheelwright S, Scahill V, Lawson J and Spong A. Are intuitive physics and intuitive psychology independent? A test with children with Asperger Syndrome,

Journal of Developmental and Learning Disorders, 2001; 4, 47–78.

18 Baron-Cohen S, Wheelwright S, Hill J, Raste Y, Plumb I. The ‘Reading the Mind in the Eyes’ Test revised version: a study with normal adults, and adults with Asperger syndrome or high-functioning autism. J Child Psychol Psychiatry, 2001;42, 241-51.

19 Sensational Kids, an interview with Ian Jordan at the UK Treating Autism Conference, Accessed August 11 2014

20 STV News, Scottish eye specialist stumbles upon ‘life-changing’ pioneering treatment, Accessed August 11 2014

21 Vision in autism an introduction by Ian Jordan, Accessed August 11 2014

22 Oxford Handbook of Synesthesia, Edited by J Simner and EM Hubbard, 2013, Oxford University Press.

23 Baron-Cohen S, Wyke MA, & Binnie C. Hearing words and seeing colours: An experimental investigation of a case of synaesthesia. Perception, 1987; 16, 761-767.

24 Banissy MJ, Holle H, Cassell J, et al. Personality traits in people with synaesthesia: Do synaesthetes have an atypical personality profile? Personality and Individual Differences, 2013; 54, 828–831.

25 Rothen N, & Meier B. The prevalence of synaesthesia in art students. Perception, 2010;39, 718-20.

26 Hupé J,Bordier C and Dojat M. The Neural Bases of Grapheme–Color Synesthesia Are Not Localized in Real Color-Sensitive Areas Cereb. Cortex,2011 doi: 10.1093/cercor/bhr236

27 Baron-Cohen S, Johnson D, Asher J, et al. Is synaesthesia more common in autism. Molecular Autism, 2013; 4:40 doi:10.1186/2040-2392-4-40

28 An introduction to the range of visual processing in asd.wmv , Accessed August 11 2014

29 Stein JF. Developmental dyslexia, neural timing and hemispheric lateralisation. Int J Psychophysiol, 1994;18,241-9.

30 Bucci MP1, Brémond-Gignac D, Kapoula Z. Poor binocular coordination of saccades in dyslexic children. Graefes Arch Clin Exp Ophthalmol, 2008;246,417-28.

31 Stein J. The magnocellular theory of developmental dyslexia. Dyslexia, 2001;7,12-36.

32 Ray NJ, Fowler S, Stein JF. Yellow filters can improve magnocellular function: motion sensitivity, convergence, accommodation, and reading. Ann N Y Acad Sci, 2005;1039,283-93.

33 Hall R, Ray N, Harries P, Stein JA. Comparison of two-coloured filter systems for treating visual reading difficulties. Disabil Rehabil, 2013;35,2221-6.

34 Dyslexia Overlays: Using Coloured Lenses: Speaker: Professor John Stein, Accessed August 5 2014.

35 Stein JF, Richardson AJ, Fowler MS. Monocular occlusion can improve binocular control and reading in dyslexics. Brain, 2000, 123 (Pt 1):164-70.

36 Stein, JF and Taylor JA. One hour wearing blue filters in the morning improves sleep quality. J Neurol Neurosurg Psychiatry, 2011;82:e4 doi:10.1136/jnnp-2011-300645.19

37 Tordjman S, Anderson GM, McBride PA, et al. Plasma beta-endorphin, adrenocorticotropin hormone, and cortisol in autism. J Child Psychol Psychiatry, 1997;38,705-15.

38 Curin JM, Terzic J, Petkovic ZB, et al. Lower cortisol and higher ACTH levels in individuals with autism. J Autism Dev Disord, 2003;33,443-8.

39 Iwata K, Matsuzaki H, Miyachi T, et al. Investigation of the serum levels of anterior pituitary hormones in male children with autism. Mol Autism, 2011; 2:16. doi: 10.1186/2040-2392-2-16.

40 Levy AD, Van de Kar LD: Endocrine and receptor pharmacology of serotonergic anxiolytics, antipsychotics and antidepressants. Life Sci, 1992; 51,83-94.

Dr Douglas Clarkson is development and quality manager at the department of clinical physics and bio-engineering, Coventry and Warwickshire University Hospital Trust

Model answers

(Correct answer is in bold text)

1    Which of the following statements about facial interpretation is true?

A    Prosopagnosia is associated with stroke but not ASD

B    Prosopagnosia is linked withimpaired function of the left fusiform gyrus

C    fMRI shows reduced fusiform gyrus function in ASD

D    Right lateral fusiform gyrus functioning is associated with faciial image interpretation

2    Which of the following statements about colour filters and ASD is true?

A    There is no published evidence of any benefit with use of coloured filkters by ASD patients

B    Ludlow has shown improvements in cognitive functioning by ASD patients using colour overlays

C    Colour overlays can only be prescribed to ASD patients capable of reading

D    All ASD patioents benefit from colour overlays

3    What is meant by the term syaesthesia?

A    Lack of sensitivity of the skin

B    Inability to detect motion

C    Cross-over linking of sensorty perception resulting in one sense responding to a different sensory input

D    The ability to suppress sensation for any given stimulus

4    Which of the following endorinological findings relating to ASD is true?

A    ACTH levels are raised

B    Beta-endorphin levels are raised

C    Cortisol levels are raised

D    There are no differences between ASD and control patient hormone levels

5    Which of the following statements about vision in ASD is true?

A    Acuity levels are typically reduced

B    Contrast sensitivity thresholds are significantly depressed

C    Binocular status is usually highly unstable

D    Visual acuity levels in ASD are usually normal

6    Which of the following is not an early indicator for ASD in an infant?

A    Lack of facial expression

B    Maintains constant eye contact

C    Displays echolalia

D    May show hypersensivity to sensory stimuli