Scientists in Italy have figured out how an episode of Pokémon may have caused epileptic seizures in 685 Japanese children in 1997.
The problem was caused by an abnormal brain response in these children to flashing lights featured in the cartoon, signaling a brain disorder known as photosensitive epilepsy. Scientists say that a mechanism in the brain that controls the reaction to visual information ‘’is defective or absent in" people with photosensitive epilepsy.
It has been known for many years that strobe lights or flashing lights may cause seizures in people with this type of epilepsy, but it was unclear how the lights induced this response. In an attempt to understand that process, Dr. Porciatti and colleagues exposed eleven patients with photosensitive epilepsy to different patterns of flashing lights and studied the brainwaves of these patients in response to the lights.
Compared with people who did not have the disorder, photosensitive epileptics had abnormal brain activity in response to slow-flashing lights with high contrast. These are the type of lights ‘’common in TV images and in video games, and may be important in triggering the abnormal (brain) response underlying visually induced epileptic seizures," the researchers write in the March issue of Nature Neuroscience.