Autism’s high rate of photosensitivityPosted: 12/13/2011
Young people with autism spectrum disorders (ASD) are far more likely than the rest of the population to be photosensitive–susceptible to visually triggered seizures from flashing light, video games, and other strong visual stimuli. Results from a new study made public last week at the American Epilepsy Society annual meeting showed that fully 25 percent of those age 15 and up with ASD are photosensitive. In contrast, the prevalence of photosensitivity among typical young people is said to be 1 in 4,000 (although I believe this is an underestimate).
For some time I’ve suspected that the rate among ASD young people is elevated, and I’ve been attempting to find funding for a study that would examine young people with ASD and their risk of seizures from video games. Here are some reasons why I believe video games pose a particularly acute seizure risk to young people with autism:
- This population develops classic epilepsy at significantly higher rates than the general population
- Children with ASD have very high rates of sensory processing disorders, including difficulties with visual processing
- Children with ASD tend to spend their leisure time with electronic media, and they exhibit a preference for animated material, thus they are likely to be heavy users of video games
Not only are young people with ASD at higher risk of visually induced seizures, they are also less likely to have their seizures noticed and properly identified:
- The unusual repetitive and nonresponsive behaviors that are common in individuals with ASD can be difficult for an observer to distinguish from seizures
- In children with ASD, impaired executive function, energy, mood, attention, and cognitive ability resulting from seizures might be masked by pre-existing chronic deficits in these functions
My guess is that photosensitivity among young people with ADHD (attention deficit hyperactivity disorder) is probably higher than average, too, because of these same factors.
Here’s why this matters so much: Although it would be difficult to change game usage habits, parents of children with autism should exercise particular caution in allowing exposure to visually overstimulating images. Reducing or eliminating visually induced seizures could result in noticeable improvements in their children’s daily functioning. The last thing these vulnerable kids need is added interference, due to seizures, with cognitive and behavioral flexibility.
The study announced last week is the first to look at the photosensitivity rate in autism. It was performed at Children’s Hospital in Boston, where researchers investigated the EEG histories of children diagnosed with ASD. More research is certainly warranted, particularly since the photosensitivity assessments were done the usual way, using photic stimulation with a strobe light. Photic stimulation may show a person’s vulnerability to seizures from a strobe light, but a strobe does not recreate the experience of exposure to a video game screen. Some individuals who do not demonstrate an EEG response to the strobe may nevertheless experience seizures provoked by video games.