Seizures from 2017’s best video gamesPosted: 02/15/2018
When you play a game ranked in the GameSpot or New Yorker Top 10 video games of 2017, the chances are about even that you will be exposed to images that could trigger photosensitive seizures. These images, which violate established guidelines for reducing the risk of photosensitive seizures, appear in 6 of the games in a combined Top 10 list. In 7 games these images were not found (some games are on both Top 10 lists).
What are photosensitive seizures?
Photosensitive seizures can occur when people with photosensitive epilepsy are exposed to intense visual stimuli: bright, rapid flashing light and bold patterns with strong contrasts. An unknown segment of the population has photosensitive epilepsy, including people with no history of seizures. It is under-reported and under-diagnosed.
In those who develop the condition, photosensitive epilepsy typically is hidden until the first noticeable seizure occurs in the presence of bright flashing or patterns. Most people with other types of epilepsy are not photosensitive. In other types of epilepsy, seizures are much more unpredictable.
Seizures can be of any type, from tonic-clonic episodes with loss of consciousness to brief absence seizures that can be as subtle as a brief hesitation or stare. Most people do not have photosensitive epilepsy, but many who do are unaware that they have the condition until a they experience a seizure during or after exposure to flashing or patterned images. Some individuals may have seizures that are too subtle to notice.
The seizure reduction guidelines test
Guidelines for seizure reduction originated in 1994, when the UK adopted technical guidelines to accommodate TV viewers with photosensitive epilepsy. These guidelines, based on studies by photosensitive epilepsy experts, outline the characteristics of flash rates and spatial patterns that typically trigger seizures in people with photosensitive epilepsy. They were later updated and some have been adopted by the World Wide Web Consortium (WC3), the international group that produces website standards for all types of applications, and the International Telecommunication Union.
The guidelines define criteria for photosensitive seizure risk involving:
- flash rate greater than 3 per second and less than 60
- stripes and geometric patterns with high contrast
- large areas of very bright (“saturated”) red
- any of the above problem images taking up more than one quarter of the total screen area
Visuals adhering to these guidelines are unlikely to provoke seizures in 97% of people with photosensitive epilepsy.
Testing video games for compliance with guidelines
Although most games carry seizure warnings, not all games contain the types of images that can bring on seizures. The warnings are not specific to the content of a given game, so consumers who pay attention to the warning don’t know whether it pertains to the game they are about to use. So I test them.
I tested the games using downloaded clips of gameplay that I loaded into an application called the Harding Flash and Pattern Analyzer. The FPA is widely used by TV producers and networks in the UK—including by the BBC—to reduce the risk of seizures from material on broadcast TV, and is used by some game studios. It examines video sequences frame by frame for very specific and measurable image qualities that research shows can trigger seizures.