Sandra Tosta, PhD – Brain Blogger Health and Science Blog Covering Brain Topics Wed, 30 May 2018 15:00:03 +0000 en-US hourly 1 The Autistic Child – More Than Meets the Eye Sat, 02 Mar 2013 12:00:55 +0000 Sensory Processing Issues and Autism

Until recently, the sensory integration issues that plague many individuals on the autism spectrum have taken a back seat to the more commonly identified social and communication issues traditionally used to diagnose the disorder. In fact, the current Diagnostic and Statistical Manual of Mental Disorders of the American Psychiatric Association (DSM-IV-TR) states that the main areas of impairment in people with autism are communication, social interaction, repetitive motion, and restricted interests. Among other proposed changes to the definition of autism, the new edition of the DSM (DSM-V) due out in 2013, proposes to include sensory integration issues as part of the criteria for diagnosis, officially acknowledging the difficulties these individuals have processing information from the five senses. For individuals with autism who experience sensory integration issues, information is incorrectly processed by the brain, often causing distress, discomfort, and confusion. These sensory processing difficulties can be an underlying cause for some of the more commonly recognized behaviors often associated with autism, including avoiding eye contact and stimming behavior. When it comes specifically to perception and what the individual with autism sees, these issues can be a result of both ophthalmological and perceptual processing disorders.

How Many Are Affected?

In a study published in the Journal of Autism Developmental Disorders in 2012, the authors reported finding ophthalmologic pathology in 40% of patients with autism, leading them to conclude that “children with autism or a related disorder will frequently have an ophthalmologic abnormality.” However, this is not the whole story when it comes to what the individual with autism spectrum disorder (ASD) sees. While we take in visual information through the eyes, this information is broken down into millions of signals that have to be processed separately by independent pathways in the brain before being put back together again into the image we ultimately see.

Conservative estimates suggest that as many as 33% of individuals with ASD have brains that do not correctly process the visual information they receive. A survey conducted in 1994 by the Geneva Centre for Autism in Toronto, Canada, suggests these difficulties may be more common, finding that 81% of those on the autism spectrum reported distorted perception. The most common problems were difficulties with depth perception; distorted perception of size, shape, and motion; seeing only small details and not the whole; and visual overstimulation. However, visual-perceptual processing difficulties are not unique to the autism community. They are experienced by as many as 50% of individuals with reading difficulties or dyslexia and can also plague individuals who have suffered traumatic brain injury, concussion and whiplash. Even a portion of the general population (many estimates suggesting 12-14%) is affected.

What Does the World Look Like?

Well-known adults on the autism spectrum such as Temple Grandin and Donna Williams have described what the world can look like for someone with autism who experiences visual-perceptual processing difficulties. In her book, Nobody Nowhere, Donna Williams says, “Colors and things and people would fly, doors would get kicked in and sometimes faces would, too. But it was never whole people, only their pieces.” This is a glimpse into the often fragmented and frightening world in which many with ASD live.

What Causes the Problem?

In the visual cortex of the brain, information about shape, movement and color is determined by magnocellular, parvocellular, and koniocellular neurons in the lateral geniculate nucleus. This information is then sent to the primary visual cortex. Theories to explain visual processing difficulties come out of the literature on reading disabilities. There are presently two theories to explain visual processing difficulties: the transient visual subsystem deficit and the cortical hyperexcitability theories. The first suggests that there are issues with the magnocellular pathway that brings information to the primary visual cortex, conveying information about motion. The second proposes that there is a lack of inhibition in the orientation columns in the visual cortex, and this lack of inhibition causes excitation to spread throughout the visual system resulting in difficulty in processing visual Information. In either case, it is suggested that color can improve perceptual processing for individuals experiencing difficulties. In 2012, both ISRN Neurology and Autism Science Digest: The Journal of AutismOne published articles discussing the positive benefits of color (in either the form of colored lenses or colored overlays) to improve the difficulties associated with perceptual processing difficulties many individuals with autism experience.

How Does Color Help?

The colored lenses modify the speed at which visual information reaches the brain and allows the brain to correctly process the information. For individuals with autism, this often means transforming a fragmented environment into a cohesive whole. For some, it can take once distorted and scary faces and make them clear, cohesive and friendly. This change in the way faces look can have a draumatic impact on the individual with autism’s willingness to make eye-contact. And because behaviors such as stimming are often performed in an effort to create calm in a chaotic environment, when the visual environment calms down, these behaviors can calm down as well. In her book, Like Color to the Blind, Donna Williams describes the difference that colored lenses made in how her world looked, “Before I saw cracked children, cracked steps, print and writing…However, the person, I did not see whole.  I saw hair, I saw, eyes, nose, mouth, child…not a face.  Now I see the whole face, the whole person…I could now perceive for the first time as a whole…I finally could do more than struggle to image an un-fragmented whole.”

Individuals with autism who also suffer from perceptual processing difficulties that may be helped by colored lenses may have difficulties with any of the following:

1) Sensory Overload caused by bright lights, fluorescent lights, and sunlight. Lighting is stressful; and this results in behaviors to filter out the light, poor eye contact, and physical symptoms such as anxiety or headaches.

2) Environmental Distortions where the individual sees the world in a distorted fashion. Objects are blurry, moving, changing, and can disappear. People may look frightening, stairs may look like a slide without steps, and walls and floors may swing and sway. Misperceptions can cause difficulties with sustained attention, eye contact, gross and small motor coordination, ability to interpret facial expressions, and poor social skills.

3) Print Distortions make learning or reading difficult. The individual may have good or even advanced reading skills but has trouble with reading comprehension or experiences strain and fatigue when reading or doing other activities. Tracking or building breaks into reading may be a problem.


Borsting, E., Ridder, W., Dudeck, K., Kelley, C., Matsui, L., & Motoyama, J. (1996). The presence of a magnocellular defect depends on the type of dyslexia Vision Research, 36 (7), 1047-1053 DOI: 10.1016/0042-6989(95)00199-9

Chase C, Ashourzadeh A, Kelly C, Monfette S, & Kinsey K (2003). Can the magnocellular pathway read? Evidence from studies of color. Vision research, 43 (10), 1211-22 PMID: 12705960

Demb JB, Boynton GM, Best M, & Heeger DJ (1998). Psychophysical evidence for a magnocellular pathway deficit in dyslexia. Vision research, 38 (11), 1555-9 PMID: 9747491

Geneva Centre for Autism (1994). The sensory experiences of individuals with autism based on first-hand accounts. Toronto, Canada: Geneva Centre for Autism.

Grandin, T. Thinking in Pictures: And Other Reports from My Life with Autism. New York: Doubleday, 1995.

Huang J, Zong X, Wilkins A, Jenkins B, Bozoki A, & Cao Y (2011). fMRI evidence that precision ophthalmic tints reduce cortical hyperactivation in migraine. Cephalalgia : an international journal of headache, 31 (8), 925-36 PMID: 21622479

Hubel, D.H. (1995). Eye, Brain, and Vision. New York: Scientific American Library; 2.

Ikeda J, Davitt BV, Ultmann M, Maxim R, & Cruz OA (2012). Brief Report: Incidence of Ophthalmologic Disorders in Children with Autism. Journal of autism and developmental disorders PMID: 22350452

Irlen, H. (2012). A sensory intervention for visual processing deficits using precision colored filters. Autism Science Digest: The Journal of AutismOne, 04, 94-102.

Keen AG, & Lovegrove WJ (2000). Transient deficit hypothesis and dyslexia: examination of whole-parts relationship, retinal sensitivity, and spatial and temporal frequencies. Vision research, 40 (6), 705-15 PMID: 10824271

Kranowitz, C. (2005). The Out-of-Sync Child: Recognizing and Coping with Sensory Processing Disorder. New York: Penguin Group Publishers.

Ludlow, A., Taylor-Whiffen, E., & Wilkins, A. (2012). Coloured Filters Enhance the Visual Perception of Social Cues in Children with Autism Spectrum Disorders. ISRN Neurology, vol. 2012, Article ID 298098, 6 pages, 2012. doi:10.5402/2012/298098

Ludlow, A., Wilkins, A., & Heaton, P. (2006).  The effect of colored overlays on reading ability in children with Autism.  Journal of Autism and Developmental Disorders. Spring 2006.

Williams, D. Like Color to the Blind: Soul Searching and Soul Finding. New York: Times Books, 1996.

Williams, D. Nobody Nowhere: The Remarkable Autobiography of an Autistic Girl. New York: Times Books, 1992.

Wilkins A, Huang J, & Cao Y. (2004). Visual stress theory and its application to reading and reading tests. Journal of Research in Reading, 27(2), 152-62.

Image via Snvv / Shutterstock.

]]> 10
Do Fluorescent Lights Give You Headaches? You’re Not Alone Wed, 19 Dec 2012 12:00:30 +0000 Fluorescent lights are everywhere — in schools, hospitals, grocery stores, the shopping mall, and now, more than ever, they are also in our homes. With recent initiatives to increase energy efficiency, individuals are regularly swapping out their incandescent light bulbs for fluorescent bulbs in their bedside table lamps and kitchen pendant lights. The result is simply a lower energy bill for most, but for the 37 million Americans who are light sensitive, this small change can add to the constant stress their brains are under as a result of bright and fluorescent lighting.

Since 1980, research has repeatedly documented the presence of, and difficulties associated with, a little known disorder known as Irlen syndrome. Irlen syndrome is a perceptual processing disorder affecting 12-14% of the general population and characterized by a variety of physical symptoms exacerbated by bright lighting (bright lights, fluorescent, computer screens, iPhone, white paper, white boards) and visually intensive activities.

Three decades worth of psychological and educational research has documented the difficulties individuals with Irlen syndrome experience, including issues with print clarity and stability, headaches, migraines, nausea, depth perception, and fatigue. But only recent research utilizing advanced brain mapping technology has revealed exactly what the brain looks like when individuals with Irlen syndrome are exposed to bright lighting and tasked with visually intensive activities. Researchers have utilized functional magnetic resonance imaging (fMRI), visual evoked responses (VER), and single photon emission computed tomography (SPECT) scans to objectively document the profound effects of sensory overload on the brain. In one study by Amen and colleagues, comparing the brains of 42 people with Irlen syndrome to 200 age-matched individuals without any evidence of Irlen syndrome, SPECT showed increased activity in the brain’s emotional and visual processing centers and decreased activity in the cerebellum (an area that helps to integrate coordination and new information).

For these individuals, lighting and glare, high contrast (black print on white paper), and visually intensive activities create high levels of stress for a brain that is unable to correctly process the visual information being sent to it. Fluorescent lights are exceptionally troublesome for individuals with Irlen Syndrome and tend to trigger and exacerbate symptoms, including headaches and migraines. Their brains have difficulty processing specific wavelengths of light, and the offensive wavelengths of light create stress for the brain, resulting in over-activity, complex brain patterns, and non-normalized functioning. This results in a variety of issues, including difficulties reading because letters and words blur or move on the page; issues with glare or discomfort from the white background on the printed page; physical symptoms, such as headaches, migraines, nausea, eye-strain and fatigue; and depth perception issues. In addition, when the brain is under constant stress from lighting conditions and the environment, it can impact functioning of the entire nervous system, resulting in not just physical symptoms like headaches and migraines, but also impacting the auto-immune system, allergies, sleep patterns and overall energy levels.

Color Can Ease the Pain and Normalize the Brain

For those with Irlen syndrome, it is possible to remove the stress on the brain by using colored spectral filters (worn as glasses). The correct color will filter out the specific wavelength(s) of light to which the individual is sensitive. This modifies the speed at which visual information reaches the brain and allows the brain to correctly process the information, eliminating physical discomfort and distortion on the printed page and in the environment. SPECT scans show that when an individual with Irlen syndrome is wearing the correct color, most of the hotspots showing overactive brain activity disappear. This translates to a calm brain, elimination of headaches, migraines and other physical discomfort, and increased ability to process visual information.

The important thing to remember is that most people don’t have any problem with fluorescent lighting — it does not give them headaches, it does not make it harder for them to read, it does not affect how their brains function. However, for those who make up the estimated 37 million Americans who are light sensitive, fluorescent lighting can have a dramatic effect on the brain and the individual’s ability to process visual information successfully and pain-free. Color can alleviate light sensitivity and related difficulties and discomfort for many.


Chronicle EP, & Wilkins AJ (1991). Colour and visual discomfort in migraineurs. Lancet, 338 (8771) PMID: 1681246

Huang, J., Zong, X., Wilkins, A., Jenkins, B., Bozoki, A., & Cao, Y. (2011). fMRI evidence that precision ophthalmic tints reduce cortical hyperactivation in migraine Cephalalgia, 31 (8), 925-936 DOI: 10.1177/0333102411409076

Irlen, H. (2010). The Irlen Revolution: A Guide to Changing Your Perception and Your Life. New York: SquareOne Publishers.

Kruk R, Sumbler K, & Willows D (2008). Visual processing characteristics of children with Meares-Irlen syndrome. Ophthalmic & physiological optics : the journal of the British College of Ophthalmic Opticians (Optometrists), 28 (1), 35-46 PMID: 18201334

Lewine, J.D. (1999). Changes in visual evoked magnetic field for people with Scotopic Sensitivity/Irlen Syndrome. Newcastle, Australia: Fourth Biannual Australasian Irlen Conference, May 20-22.

Riddell PM, Wilkins A, & Hainline L (2006). The effect of colored lenses on the visual evoked response in children with visual stress. Optometry and vision science : official publication of the American Academy of Optometry, 83 (5), 299-305 PMID: 16699442

Robinson, G.L. (1994). Coloured lenses and reading: a review of research into reading achievement, reading strategies and causal mechanisms. Australian Journal of Special Education, 18, 3-14.

Robinson GL, McGregor NR, Roberts TK, Dunstan RH, & Butt H (2001). A biochemical analysis of people with chronic fatigue who have Irlen Syndrome: speculation concerning immune system dysfunction. Perceptual and motor skills, 93 (2), 486-504 PMID: 11769907

Williams, M., Littell, R., Reinoso, C., & Greve, K. (1994). Effect of wavelength on performance of attention-disordered and normal children on the Wisconsin Card Sorting Test. Neuropsychology, 8 (2), 187-186 DOI: 10.1037/0894-4105.8.2.187

Wilkins, A.J., & Clark, C. (1990). Modulation of lighting from fluorescent lights. Lighting and Research Technology, 22, 103-109.

Yellen, A. (2010). Irlen syndrome: a case study. Los Angeles Psychologist, May-June, 16-18.

Image via olivier / Shutterstock.

]]> 14