Is the risk of video game seizures really one in 4,000?

genetic risk of photosensitivity and epileptic seizuresFor a lot of reasons researchers just don’t know how often video game seizures occur. The commonly used statistic of 1 in 4,000 people (and about five times that number in young people age 7-19) was carefully arrived at in rigorous clinical studies showing the prevalence of an abnormal EEG response to a flashing strobe light. It does not represent the prevalence of actual seizures triggered by today’s video game graphics.

Studies of photosensitivity began well before video games were invented. Researchers in the 1940s found that when exposed to a strobe light flashing at certain intervals, some individuals have a sudden change in their brain waves corresponding with the timing of the flash. They called this the photoparoxysmal response (PPR). The PPR does not indicate an actual seizure. The strobe is stopped as soon as the EEG changes so that the test subject doesn’t go on to have a seizure. Different researchers over time have used different criteria to define exactly what the altered brain wave needs to look like to qualify as a PPR. If your EEG shows one of these patterns in response to the strobe light, it doesn’t necessarily mean you will have light-induced seizures. It just means you’re more likely to. Playing a video game is a pretty different neurological experience than responding to a strobe light.

The obvious question is then, what is the value of the data if there is so little certainty about the meaning of the results?  I think that the EEG response to a strobe is simply the best tool that researchers have in that it provides measurable data that can be replicated in other EEG studies, and it allows relevant information to be captured without subjecting participants to seizures. It would be reasonable to be cautious around flashing lights if you’ve had an EEG that shows sensitivity to the strobe, but there’s no certainty you’d have a problem with video games.  And an EEG that does not show sensitivity to the strobe does not mean you’ve been given the green light, as it were, to play video games endlessly without needing to be concerned about seizures. Unfortunately the only way to find out if you’ve got a video game seizure problem is to encounter a game that triggers a recognizable seizure.

The point of all of the above is to give you some idea—without getting into lots of nitty gritty—of the squishiness and complexities of the data surrounding the prevalence of photosensitive seizures. In future postings I’ll talk about some other issues with the prevalence data. Next time I’ll discuss population sectors that are at higher risk.



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