Maybe you’ve heard about the video game Fortnite that now has 45 million players? One reason it’s so popular is that it’s free to download — with its seizure-inducing graphics.
Playing Fortnite involves quite a bit of shooting that creates bright flashes. The flashes are especially likely to trigger seizures when the game is played in “high explosives” mode (available during limited release dates). The high explosives create bigger explosions splayed across larger areas of the screen, which in turn affects a greater number of neurons in the brain’s visual processing system. For reasons not entirely understood, in people with photosensitive epilepsy, flashing light and certain other visual stimuli overload the visual cortex in a way that leads to seizures.
In one user-uploaded, 7-minute, 39-second gameplay video using high explosives, 8 separate image sequences failed to meet the standards for minimizing the risk of visually triggered seizures. Each of those failures represents a visual sequence with a reasonable chance of setting off seizures in persons who have photosensitive epilepsy. The test for seizure risk from images is based on guidelines for reducing visually induced seizures, determined by extensive research on the image qualities that can bring on seizures in people with photosensitive epilepsy: motion, brightness, contrast, patterns, color intensity, and flash/flicker .
Please fix this, Epic!
Fortnite’s developer, Epic Games, has come out with remarkably frequent product updates to address performance bugs and keep players’ interest from flagging. (No issues with maintaining players’ interest level — maybe you’ve also heard about parents and teachers struggling to handle kids’ unprecedented preoccupation with this game?) Last week Epic removed a guided missile weapon from the game — for now — due to a bug and some player feedback that using the weapon disturbed the sense of fairness and balance of the game. That still leaves grenades, rocket launchers creating big flashes in high explosives mode.
Perhaps the company’s unusually rapid product development cycle would make it possible to modify all the game’s graphics where the image sequences place users at risk of seizures? There are tools available to developers to identify the offending images — what I use to test the gameplay clips is just another version of the same Harding Flash and Pattern Analyzer software. You can read here about the way I do the testing.
Should you be concerned?
Maybe. Estimates are that up to 3 percent of the population has photosensitive epilepsy (among those with any other form of epilepsy, about 5 percent). Photosensitive seizures typically begin between ages 8 – 20, and they can occur in people with no history of epilepsy. Of the hundreds of children who had seizures during a 1997 Pokémon cartoon broadcast in Japan, researchers found that 74 percent of them had never been aware of experiencing a seizure before.
Prevalence of photosensitive epilepsy is probably underestimated because seizures are not always noticeable, and therefore they are not always reported. The symptoms of a mild seizure may be so subtle that nobody realizes what’s occurred. That doesn’t mean a mild seizure is nothing to worry about; any seizure has the potential to leave disabling physical and cognitive after-effects and mood changes that can last for days.
What can you do?
Parents and teachers are struggling to handle kids’ unprecedented preoccupation with Fortnite. To learn about the effects of video games on the central nervous system, and about finding ways to reduce your child’s screen time, I recommend Dr. Victoria Dunkley’s Reset Your Child’s Brain: A Four-Week Plan to End Meltdowns, Raise Grades, and Boost Social Skills by Reversing the Effects of Electronic Screen-Time.
To learn if your child may be experiencing game-induced seizures, ask about any weird sensations occurring while playing video games. See if you can get the child to wear cobalt blue dark glasses while gaming; in these are extremely effective at protecting against or reducing the severity of seizures.
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.
Riot Games, publisher of the hugely popular League of Legends game, responded quickly to a user reporting a seizure from the game. What happened this month is both a short and sweet case study in customer care, and a mystery.
Two days after a new animated log-in screen for League of Legends appeared, two users reported on a forum that the visual effects of that image caused a seizure. Several others said that the jerking of the image every few seconds produced uncomfortable and unusual sensations.
After the first user posted about his experience, Riot Games:
- took down and replaced the animated image
- announced the fix
- noted the company already uses software to test its games for seizure-triggering images and added, “…but if that isn’t enough we need to know.”
- thanked the user for pointing out the problem so it could be fixed
You can read the respectful exchange that unfolded in the League of Legends subreddit here.
In this instance, the fix was simple. Since the image sequence causing the problem occurs in an isolated part of the code, outside of game play itself. Riot Games simply replaced the login-in screen with a prior version. Riot posted this update: “We take this stuff super seriously and we’re grateful to [the original poster] for raising visibility on the issue so we could solve it.”
The mystery: What triggered the seizures?
On to the mystery. If Riot uses software to test its games for the possibility of triggering seizures, how did this image get through the testing process? Looking at the image (I do not have photosensitive epilepsy) it doesn’t show obvious violations of image safety guidelines. Because there’s an interval of some seconds between the periodic vibration of the image, those shifts don’t create a flashing effect. (One user described it as a “shudder.”) And there are no bold patterns that trigger seizures in some individuals.
I ran the image sequence through the seizure guidelines test software and, sure enough, the periodic shake barely registered. I consulted Prof. Arnold Wilkins of the University of Essex, a leading researcher in visual effects that influence the brain.
He examined the sequence frame by frame (video typically runs at about 30 frames/second) and found a single blurred frame in each “shudder” that differed from the rest. He suggests that the resulting disruption in an otherwise stable image is “profoundly disturbing” to the visual system. Prof. Wilkins advised that even wearing colored lenses, which are remarkably effective in reducing or eliminating seizures triggered by flicker, probably would help only slightly in this instance.
No guarantees of safety
While many of the guidelines for seizure-causing images have been carefully defined through research, we clearly don’t know everything yet. So even developers who follow image safety guidelines and test their products for a gaming experience without seizures can produce visual effects that are unsafe for those with photosensitive epilepsy.
Five of New York Magazine’s top ten video games of 2016 don’t meet guidelines for reducing the risk of visually provoked seizures. Developers of these popular games could have designed the visuals in a way that lowers the seizure risk to users, but didn’t.
Guidelines for reducing the risk of seizures triggered by video images were published in 1994, when the UK required that all TV programs and advertisements meet those visual safety standards. The same guidelines for making television images safer could easily be adhered to when developing video game visuals. No regulations on seizure-inducing images in video games have ever been enacted, so game developers have no incentive to work within the guidelines.
Instead, for many years game publishers have provided a seizure warning that makes it extremely difficult for consumers to take legal action in case of a seizure. Some games may in fact conform to seizure-reduction guidelines, but because the seizure warnings appear on all games, consumers can’t know which ones are riskier. The warnings began appearing in 1991 in response to the first video-game-seizure consumer lawsuits.
What compliance with the guidelines means
Many popular games don’t meet the guidelines, as demonstrated by my testing of New York Magazine‘s favorite games. A couple of the failing games were among the top five first-person shooter games selected by Forbes.
I tested video clips from gameplay and promotional trailers for the games on the list using software that identifies video sequences that don’t comply with the guidelines. The software is designed for game developers and video producers to test their moving images for compliance.
Note that for the games that didn’t violate the guidelines, rather than list them as passing the compliance test, I’ve indicated that they did not fail the test. Although in previous posts with test results I’ve listed games that “passed” the guidelines test, I’m no longer using that terminology. That designation could too easily be misinterpreted to mean that such games will definitely not cause seizures.
Even if a game doesn’t fail the guidelines compliance test, there is still a risk of seizures, for several reasons:
- I may not have tested a portion of the game with problem image sequences
- The guidelines aren’t fool-proof. They are designed to prevent seizures in approximately 97 percent of people who have photosensitive epilepsy, the condition where visual stimuli can trigger seizures.
- Many environmental and personal health variables–such as lack of sleep or illness– can affect an individual’s vulnerability to seizures
Do you need to worry about seizures from video games?
- The vast majority (97 percent) of people diagnosed with conventional epilepsy can play video games without risking a seizure because–unless their EEGs indicate otherwise–their seizures aren’t triggered by visual effects. These people don’t want others questioning their fitness for gaming.
- People with no history of epilepsy may be most at risk. Seizures can be triggered by flash and flicker even in people with no history of seizures, which means that many don’t know they are at risk of having a visually triggered seizure until a video game brings on their first event. Of the children who had seizures during the 1997 Pokémon cartoon broadcast in Japan, only 24% had previously experienced a seizure.
- Visually triggered seizures typically begin between ages 2-18, and most commonly begin around age 12-13. Of patients age 7-19 who seek medical attention for a seizure, ten percent test positive for photosensitive epilepsy. Researchers estimate that only 25 percent of people outgrow the condition, typically in their twenties.
- It is relatively unusual but not unknown for these seizures to develop in adults. Because in many individuals a number of factors (for example, emotional state and hormone levels) affect seizure vulnerability, a seizure may not actually occur until several of these factors are present simultaneously. Even one seizure can be life-changing if it results in injury or permanently bars an individual from certain occupations.
- It is also possible to experience subtle seizures and not realize they happened. This doesn’t mean there are no seizure consequences, though. Typically after seizures one’s physical, cognitive, and emotional functioning can be impaired.
More on the guidelines and how games are tested for seizure risk
None of the five video games picked by a Forbes reviewer as the year’s best first-person shooters meet safety guidelines for reducing the risk of visually triggered seizures.
The fast-moving, flashing images in these five games could provoke seizures in people whose seizures are triggered by visual stimuli, due to a sometimes hidden condition called photosensitive epilepsy. I tested image sequences from these popular games using software designed for checking the adherence of images sequences to the seizure reduction guidelines. All five failed:
Game developers could — should — use this same technology to build products compliant with the guidelines! The application I used to test the games for compliance isn’t a consumer product; it’s intended for developers. Instead of building games that comply, many developers simply place seizure warnings on games and consoles. People with no history of seizures don’t pay much attention to seizure warnings, though. Why would they?
Reason #1 consumers don’t know they may be at risk
Photosensitive epilepsy most often develops in adolescence and remains hidden until it’s activated by particular stimuli and circumstances. If earlier in life visual stimuli didn’t trigger an event, how does one know that’s no longer true?
According to one study, 74 percent of individuals with photosensitive epilepsy first learn they have the condition when they experience a seizure in the presence of flashing lights or another visual stimulus. This study was based on the histories of hundreds of children who had seizures during a 1997 Pokémon cartoon broadcast in Japan.
Sometimes the first seizure triggered by a video game can have life-changing consequences. A Navy pilot who played Oblivion, had a seizure that produced injuries and resulted in permanent loss of his flight clearance. Think of the medical testing he underwent before he was trained to fly–obviously his seizure vulnerability had not yet developed.
Reason #2 consumers don’t know about their risk
Some seizures aren’t noticeable. This means that included in the 74 percent who (think they) never had a prior seizure, there are some people who may already be experiencing them without realizing it. Subtle seizures involving no body movement may not draw the attention of others nearby, either.
People with no history of seizures aren’t aware that undetected seizures exist and therefore may dismiss any unusual physical or mental sensations while gaming. If the seizure causes a loss of awareness for a few seconds, the person will not be “present” at that moment to recognize what’s happening or remember it later. For more on undetected seizures, see the section “Research shows people often don’t detect their own seizures” in this post.
Note that undetected seizures as well as more obvious events can bring on a range of disabling physical and cognitive after-effects and mood changes that can linger for days.
Not all video games violate the image safety guidelines. Even though video games typically carry seizure warnings, the warnings don’t reflect the seizure risk of any particular game. Unfortunately, consumers have no way of knowing which games are in compliance and which are not.
Let’s say you’re an informed consumer, aware that some games can pose a seizure risk and you’d prefer not to take that risk. You understand that a game with lots of bright flashing is more likely to be a problem, but you can’t really know whether a specific game that you want to play is more likely to trigger seizures. How can you play only games that meet guidelines and avoid only the noncompliant ones? (This is where the testing I can do can identify certain cases of noncompliance.)
- The vast majority (97 percent) of people diagnosed with conventional epilepsy can play video games without risking a seizure because their seizures aren’t triggered by visual effects. These people don’t want others questioning their fitness for gaming.
- Want to know more about how I test video games? About the image safety guidelines? Read here.
- For the record, Forbes states that opinions of contributing writers (such as this guy who picked the five games) are their own, not the magazine’s.
In recent weeks photosensitive epilepsy received some media attention because of two developments in the 2016 presidential campaign. Who would have thought? While the public probably didn’t learn much about photosensitive seizures in either case, perhaps both situations contributed something to public awareness of seizures triggered by certain lighting effects and images…
Clinton’s blue sunglasses
After Hillary Clinton’s widely publicized medical emergency on September 11, various bloggers and political writers rushed to speculate about possible causes of the episode. Photos of Clinton taken that day showed her wearing sunglasses that appeared dark blue, and some people wondered whether the glasses provided a clue to an undisclosed medical condition.
Visits to this blog surged for several days. More than 95 percent of the nearly 24,000 visitors from September 11 – 13 read two of my prior posts about blue lenses that protect against visually induced seizures. A few readers questioned whether the sunglasses seen on Clinton were the type worn to prevent photosensitive seizures.
My answer was maybe yes, but probably not. Since photos of Clinton that day showed her wearing them outside during the day, they weren’t likely worn for seizure protection. Flickering light doesn’t generally trigger seizures outdoors in daylight and good weather—for flicker to occur there has to be an extreme contrast of light and darkness in rapid succession. It’s certainly possible to have photosensitive seizures triggered outside in daylight, in specific situations: sunlight reflected on a body of water, or a line of trees seen from a moving vehicle, where sunlight is broken up by trees alongside the road. But Clinton was not in those settings when wearing the glasses.
Seizure-inducing images tweeted by angry reader
In a separate election-related incident, the matter of photosensitive seizures was taken in a troubling direction. In response to articles he wrote critical of Donald Drumpf, Newsweek journalist Kurt Eichenwald received a menacing tweet from an unhappy reader that referred to Eichenwald’s epilepsy and included an embedded video of flashing images. When the video started, Eichenwald dropped his iPad before a seizure could develop.
It certainly wasn’t the first time seizure-inducing images were placed online for the purpose of triggering people with photosensitive epilepsy, but it’s the first instance I’m aware of that’s tied to this rancorous political season. Criminal defense attorney Scott Greenfield claimed in his blog that the episode qualifies as an attempted assault. “Yes, even Twitter can be used to commit an assault, regardless of whether Eichenwald was a victim,” he wrote.
For more on the legal and technology issues raised by the tweet to Eichenwald, check out this Future Tense article, in which UC Davis law professor Elizabeth Joh concludes, “…the existing tools of criminal law probably do address a tweet likely intended to harm its recipient or to create a reasonable apprehension of fear in him.” But she adds, “That doesn’t speak to the likelihood of prosecuting the troll, which may be low.”
People who have photosensitive epilepsy probably are already cautious about going to amusement parks, since lots of rides and other attractions feature fast-moving lights and flashing images. Now there’s another reason they should be wary: video game-based attractions are coming to amusement parks, and some of those games have seizure-inducing images.
“The game manufacturers and game designers want to have a place to show their games at a scale that you can’t do in your house,” according to the CEO of Cedar Fair Entertainment Company, which owns 11 amusement parks. To put it another way, they’re blowing up the visuals of an action video game with seizure risks, and displaying those images on a huge screen!
Here’s the problem with that: Images on an oversized screen have a greater impact on the brain’s visual cortex than the same images viewed smaller. This means that even if a person with some degree of visual sensitivity plays Mass Effect on an Xbox, without incident, that person would be more likely to experience a seizure at the theme park attraction.
Games don’t comply with seizure guidelines
An attraction based on BioWare’s Mass Effect opened last month at California’s Great America theme park—on a 60-foot LED screen. Curious about whether the at-home games contain potentially seizure-provoking images, I tested** the images in promotional trailers for Mass Effect 3 and Mass Effect 4. I found violations of seizure reduction guidelines in both. A 15-second commercial for Mass Effect: New Earth also fails the test for compliance with the guidelines.
At North Carolina’s Carowinds amusement park, “the world’s first intra-active 3-D game experience” Plants vs. Zombies Garden Warfare: 3Z Arena opened in March. It’s shown on screens measuring 14.4 x 26 feet.
The attraction is based on the Plants vs. Zombies franchise. In my tests, some clips from the Plants vs. Zombies Garden Warfare game violate seizure reduction guidelines. I didn’t have video I could test of the park’s big-screen experience.
When designing an attraction based on a game with seizure-provoking images, shouldn’t the theme park industry be especially mindful of patrons with photosensitive epilepsy? Warnings at the park about rides that could be hazardous to patrons with certain medical conditions such as pregnancy, heart conditions, or epilepsy aren’t enough. Many people don’t even know about their vulnerability to seizures from certain visual effects until they have an unmistakable seizure. Not all seizures are easily noticeable! And even small seizures that aren’t seen can leave impairing after-effects.
Coming next: Entire theme parks based on games
Video game-based attractions at amusement parks are expected to multiply. Universal Studios and Nintendo signed a deal last year to bring Nintendo-based attractions to Universal’s theme parks. The first of these, slated for 2020 completion, will be a whole section of Nintendo-based attractions at an existing theme park in Osaka, Japan. Industry observers suspect that Universal’s recent land purchase in Orlando is intended for a Nintendo-based expansion of its Universal Orlando theme park. Ubisoft has announced an entire “next generation theme park” scheduled to open in 2020 in Kuala Lampur, Malaysia, with rides and attractions based on its portfolio of game franchises.
**Seizure reduction guidelines and testing images for compliance
You can read about seizure reduction guidelines here–they were developed in the UK to reduce the risk of seizures induced by TV. All material broadcast on UK television must comply with the guidelines.
To test images for the likelihood of provoking photosensitive seizures, I run downloaded video clips through an application called the Harding Flash and Pattern Analyzer. (Graham Harding is one of the world’s leading experts on photosensitive epilepsy.) The FPA is widely used by producers and networks in the UK—including by the BBC—to reduce the risk of seizures from material on broadcast TV.
The analyzer examines video sequences frame by frame for very specific and measurable image qualities that researchers have found can trigger seizures. When such images are found, it displays and indicates the specific frames that violate seizure reduction guidelines. Violations occur with:
- rapidly alternating light and dark images (flash/flicker)
- certain stripes and geometric patterns with high contrast
- large areas of very bright (“saturated”) red
- problem images take up more than one quarter of the total screen area