Feb. 29, 2000 (Atlanta) -- Increasing use of video games and television watching will likely lead to an increase in seizures -- but only in certain people, according to Italian researchers. They conclude that a defect in how the brain handles light stimulation -- especially when it comes to light contrast -- promotes the seizures, which have been associated with the Pokémon animated television series. In 1997 nearly 700 Japanese children had seizures while watching an episode of that cartoon.
Researchers found that the brains of people who have a history of seizures caused by viewing flashing lights essentially lost electrical control when presented with a barrage of light stimulation. The problematic type of light contrast -- high contrast in black and white light -- and the problematic flashing light frequency that caused study participants to have more electrical brain abnormalities are common in television images and in video games, according to the researchers.
"We know something about what intensity, pattern, and frequency is most likely to push susceptible brains ... into a seizure," says Philip Sheridan, MD, program director for Pediatric Neurology at the National Institute of Nerve Disorders and Stroke, Bethesda, Md. "There may be some implications in terms of what broadcasting parameters should be used and viewed as most safe."
But Sheridan cautions that you can't always blame the TV: "Now TV is so ubiquitous that sometimes a child will have their first seizure sitting in front of the TV -- even though the TV has nothing to do with it.
If TV is the cause of the seizure, Sheridan has two common sense recommendations for parents: "[Children] should be at least 8 feet away from the television set and they should watch TV in a well-lit room. That's enough to protect most children," he says. Some highly sensitive kids may also need to wear polarizing sunglasses outdoors.
The study authors say their findings might lead to more thoughtful construction in video games. One expert says that's already happening. "We have designed a number of children's games, and when we do those, we look at how it's going to affect them psychologically," says Jason Short, program director at Full Sail Real World Education in Winter Park, Fla., a facility that teaches video game design. "You're selling to the parent, and part of what you're selling is that it's going to be a wholesome experience."
Short says part of that wholesome experience is to minimize the risk for light-induced seizures. "When we design the games, we try not to use strobe systems or colors that might trigger a seizure." For example, he says red spots flashing on white could be a problem, especially if they were pulsing at a certain rate.
Flashing spots was the issue with the Pokémon seizure outbreak, Short says. The Japanese children were hit with black on white strobing at an optimal rate for producing seizures.
- Italian researchers report that many children could be naturally prone to seizures if they are barraged by certain patterns of light. This could explain why many Japanese children had seizures during a Pokémon television show in 1997.
- Nerve specialists know some of the light patterns that can cause problems, and such information may be useful when creating safe television programming and video games. But televisions are not responsible for triggering seizures in all cases.
- Doctors say children sensitive to these seizures should stay at least 8 feet from the television set and watch TV in a well-lit room. Highly sensitive children may need to wear polarizing sunglasses outdoors.