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.
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.
What do a pineapple playing tennis and a grape going for a ride have in common? Two things: 1) They’re currently appearing in Google’s Olympics-themed iOS and Android Doodle Fruit Games app, and 2) viewing them in Google’s video promoting the app could give you a seizure.
For the next two weeks while the game app is available, Google is promoting it with a zippy, fast-paced trailer. Visitors watching the trailer see rapidly moving images images that could provoke seizures in anyone with a condition known as photosensitive epilepsy. I tested the trailer for its risk of inducing seizures and found two segments–involving the aforementioned pineapple and grape–with a flashing effect that could trigger photosensitive seizures. From what I can tell, the problem images appear only in the trailer and not in the games app itself–unless they appear only after players achieve a high score that I didn’t reach.
What is photosensitive epilepsy?
Photosensitive epilepsy is more common than is generally known, and researchers agree it is probably underestimated. People with the condition have epileptic seizures triggered by lights or images that flash faster than three times per second.
It gained some notoriety after a Pokémon cartoon shown on Japanese TV in 1997 sent nearly 600 children to emergency rooms with seizure symptoms. The condition had already been extensively studied and researchers had drawn up guidelines for reducing the seizure risk from video images, but at the time Japan did not protect TV viewers from problem images.
Who is affected by photosensitive epilepsy?
The vast majority of those with “regular” epilepsy are not affected by visual stimuli. But photosensitive epilepsy may be harder to detect and is underrecognized by the public and by doctors. You may be susceptible to photosensitive seizures and not even realize it since:
- Photosensitive epilepsy typically doesn’t develop until adolescence.
- It can occur in people with no history of seizures. Of Japanese children affected by the Pokémon cartoon, 76 percent had never before experienced a seizure.
- People with other forms of epilepsy are routinely tested for photosensitive epilepsy, but the condition may be most common in individuals who don’t have any other type of seizures. These people are very unlikely to be screened for it.
You can already be experiencing seizures and not know it.
- Not all seizures involve complete loss of consciousness, falling, or body movement observable by others. Such major events, known as generalized seizures, occurred in less than half of the Pokémon-affected children.
- Because consciousness is altered at the time, a person having a seizure often has no memory of it.
Even if you have no visible symptoms of a seizure, there can be lingering after-effects that include fatigue, sleep, learning, and memory problems, mood irregularities, among others.
How the media and entertainment industry can reduce seizure risk
More than 20 years ago, researchers studying photosensitive epilepsy defined the factors, in particular the flash frequency, that are most likely to provoke visually induced seizures.The UK has required all TV content to conform to seizure-reduction guidelines since 1994, and Japan enacted similar regulations following the Pokémon incident. To date, no other countries have done this, but a United Nations-affiliated agency did adopt recommendations for reducing photosensitive seizure provocation from television. Meanwhile, of course, interactive media have become a much bigger part of our lives than television, and the same guidelines for reducing seizures from TV should be adapted to the internet.
The World Wide Web Consortium (WC3), the international group that produces website accessibility standards for all types of applications, now includes guidelines for reducing the risk of visually triggered seizures. But incorporating such standards into private industry applications and sites is a hugely complex and time-consuming process.
The United States Department of Justice has been considering since 2010 the complexities of creating regulations ensuring access by the disabled to public and private websites. The DOJ announced this spring that rules governing private websites have been delayed until 2018 at the earliest.
In 19901, after a few consumer lawsuits were filed due to seizures, game developers began including a seizure warning that has kept consumers from filing or winning such lawsuits. Although most game documentation and packaging contain a seizure warning, not all games contain seizure-provoking visuals. Consumers don’t know which games actually have potentially harmful sequences and largely ignore the warnings.
How you can prevent photosensitive seizures
If you’re susceptible, even a brief exposure of a few seconds to flashing can be enough to bring on a seizure. If you know that you are vulnerable to these seizures, there are some precautions doctors recommend to avoid being triggered:
- When possible, avoid situations and stimuli that are likely to be provocative, including emergency lights, electronic billboards, video games, light shows, flickering fluorescent lights, fireworks, animé and other fast-moving cartoons
- Wear blue-colored glasses, which filter out the most provocative light frequencies. Most opticians can make these inexpensively.
- In the presence of flashing light, cover one eye.
- Increase your distance if possible from the flashing image–so, for example, stay at least 6 feet from your TV screen, and don’t play video games up close.
- Don’t play when fatigued or sleep-deprived.
- Take frequent breaks during prolonged exposure–although this won’t always help if you are triggered in a matter of seconds.
Testing for visuals that can provoke seizures
I tested the trailer using an industry-standard application called the Harding Flash and Pattern Analyzer that detects image sequences that can trigger photosensitive seizures. It is based on algorithms devised by Graham Harding, one of the world’s leading experts on photosensitive epilepsy. The application 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.
Seizures from video shown on TV about 2012 Olympics logo
This is not the first time that Olympics-themed promotional visuals have placed viewers at risk of seizures. A promotional video for the logo of 2012 London Olympics logo shown on British TV news in 2007 resulted in seizures in some viewers. It had not undergone the required testing that would have alerted producers to the problem prior to broadcast.
Terrible idea. Take a genre of video games—first person shooter– that is especially likely to provoke seizures. Make an action movie filmed entirely in that style. Put it on the big screen for release in theaters. The larger an image is, the greater the area affected in the brain’s visual cortex, and therefore the risk of visually triggered seizures is increased in those who are vulnerable.
Hardcore Henry opened (and in most cases, also closed) in theaters this month. It’s described by the student newspaper of Washington College as 90 minutes of “non-stop chase scenes, splatterhouse shootouts, and barely comprehensible fistfights that often end in ridiculous dismemberment.” Glenn Kenny’s New York Times review explains the film’s R rating thusly: “for not letting a minute pass without subjecting one character or another to grievous bodily harm or worse.”
I suppose it’s possible to produce such subject matter without seizure-inducing images, but given such descriptions of the content, I wanted to check. Without going the movie. So I tested** the movie’s promotional trailers for compliance with seizure reduction guidelines. The guidelines were designed to protect all but 3 percent of those who may have seizures triggered by visual stimuli. After watching the trailers (I do not have photosensitive epilepsy), I was not at all surprised that the movie does not comply.
This is hardly the first movie to include images that could trigger seizures. But based on the trailers and reviewers’ accounts of a relentless pace of action, most likely there are many potential seizure triggers during the film. Researchers of photosensitive epilepsy believe there is a cumulative effect on the brain; the risk of a seizure increases after prolonged exposure to potential triggers.
Strong stomach required
Many reviewers of Hardcore Henry cautioned readers about motion sickness. One reviewer interviewed the movie’s producer about apparently significant (yet not entirely successful) efforts to minimize it. The producer said those efforts were begun long before film production began, with many tests and test screenings.
Some representative remarks:
“…many people are going to feel ill when they try to watch Hardcore Henry on the big screen…make sure everyone in your party either has no issue with motion sickness, has taken their Dramamine, or rolls into the theater with an empty stomach…” — The Daily Dot
“…as I waited for my nausea to subside, I began to appreciate the dastardly marketing plan built into Hardcore Henry: It’s essentially a dare to see if audiences can finish the whole thing without throwing up.” — Vox.com
“Hardcore Henry will probably go down as the film of 2016 that is most likely to make you feel nauseous from watching it (due to motion sickness, that is, not the gory, over the top violence).” — Screenrant.com
Back-handed seizure warnings
A number of reviewers mentioned seizures, but not with the same concern with which they write about motion sickness. Sure, motion sickness is unpleasant, but a seizure is not only unpleasant, it can be dangerous and life-altering, and its effects on the brain can linger. You wouldn’t know it from these reviewer comments, though:
“It’s remarkably watchable, in fact, with none of the motion sickness you might expect, which is especially amazing given the film’s unswerving dedication to full-bore, seizure-inducing action.” – The Georgia Straight
“…Hardcore Henry is a 90-Minute Cinematic Seizure…a frenetic editing style that can make you feel like you’re having some kind of seizure…I don’t see how anyone could watch it and not experience motion sickness…I definitely felt like I’d suffered from some sort of brain trauma when I walked out of the theater. (Can you get a concussion just from watching a movie?)” — Esquire
Treating seizures (and those who have them) with respect:
Just 2 reviews of dozens I read seemed to be genuinely concerned about the movie’s potential to trigger photosensitive seizures in audience members:
“If 3D gives you a headache, Hardcore Henry is enough to bring on epilepsy.” — Moviehole.net
“I left the theater wondering if the jittering, disoriented feeling I had buzzing through my skull was some sort of sudden onset epilepsy.” — University News
If you live in the UK, there are real warnings about the risk of visually induced seizures. Listings for movies with images that don’t comply with seizure reduction guidelines warn of “a sequence of flashing lights which might affect customers who are susceptible to photosensitive epilepsy.” That’s because the UK regulates the appearance of TV, movies, and advertising to protect those individuals. Some of these people with photosensitive epilepsy don’t realize they have the condition. It may have developed only recently or it’s quite possible they were never aware of experiencing a seizure. Not all seizures look like what you typically see portrayed.
What lies ahead?
What’s most worrisome is that the consensus among reviewers — regardless of how well they liked Hardcore Henry — is that the influence of video games on movie-making is only going to grow.
“Virtual reality is on the way. Video games and movies will soon start to blend and borrow from one another in many ways. And this movie, imperfect and nasty and often astonishing, is a vanguard.” — Slashfilm.com
“…the visual language of games will soon come to have as much of an impact on up-and-coming film directors as cinema does… and it’s safe to say that we won’t be short of films based on video game properties…With an increased push towards the home viewing experience in movies and interactivity in media, it will be interesting to see how the cinema of tomorrow is influenced by gaming perspectives. “ — Den of Geek
We will certainly see more of the first-person perspective, too. Some hailed the project as a technical marvel and “a revolutionary approach to narrative filmmaking.”
**How I tested the movie trailer
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
It’s no secret that the relationship between powerful game publishers and the press has a long history of conflict of interest. To stay in the good graces of game studios to ensure continued early, confidential access to forthcoming products, it’s in game reviewers’ interest–and the interest of the outlets where they write–to write favorable reviews.
Game critic Jason Evangelho stepped forward last week in Forbes to declare that both video games and the way they are reviewed by industry press are broken. He called on his colleagues in the reviewing business to stop running reviews that primarily serve their respective sites and the game publishers. “Remember who reviews are for,” he admonished. They’re for consumers who count on reviews to help them decide whether to spend their money on specific games.
Evangelho pointed out how reviewers are not doing their jobs properly: “…the gaming press is shielding your eyes from serious issues,” he wrote. “If we want fewer games to launch broken, we have to hold publishers accountable.” Jason admits he’s guilty of the reviewing practices he feels need to change. “I’m not perfect, but I’m trying my best to course-correct and do what’s right for the industry and especially for its consumers.” Jason, I so totally agree…even though you aren’t talking about the seizures that games can provoke.
What he’s really getting at
Jason’s particular beef is that publishers are increasingly releasing games before they’re fully functional, and that reviewers turn a blind eye to this practice. Reviewers don’t penalize incomplete products in their ratings but instead rate the game as though all the features are already in place. This is routinely done even performance suffers due to inadequate server capacity, or some features are still missing or aren’t working right at product release. Readers are then misled by reviews that give the publishers a “pass” on missing functionality.
He then calls on readers to speak out on the review process:
“If we want fewer games to launch broken, we have to hold publishers accountable. But that first step absolutely starts with me, and with my fellow critics in the game industry. And you need to tell us that’s what you want. Ultimately, the games and the coverage of games is done for you. So wield the power you have and make your voice heard.”
So, in a nutshell: studios should stop lifting the embargo the day before product release and should stop releasing games before they’re ready, news outlets should wait to run reviews until their reviewers can evaluate the same product version that users receive, reviewers should call out missing features and rate games accordingly, and users need to speak up about the status quo.
Kudos to Jason, especially for calling out the lack of candor by reviewers due to their focus on priorities other than their readers. Of course, in so doing, Jason’s piece brings to mind other ways that reviewers could help and advocate for their readers, if they chose.
Tell reviewers you want them to assess games for seizure risk
If you agree that game reviewers should be more accountable to their readers, more responsible and more cognizant of their potential to influence publishers, then why not urge reviewers to address the seizure issue? It wasn’t what Jason was asking readers to do — but it’s all part of better serving readers. Certainly reviewers could influence the industry by writing about video game seizures and thereby holding publishers accountable.
I responded to the Forbes piece, commenting that consumer product reviews should address product safety issues. Here’s what I wrote (with a few minor edits):
Holding publishers responsible goes further than what you’ve described. Responsible reviewing for any consumer product should consider basic safety issues, and this has never been the case in video game reviews. We don’t expect consumers to test product safety, but in the case of video games, reviewers have left crash-safety testing to the consumer.
Many games expose consumers to a serious health hazard: seizures–many of them undetected— provoked by excessive flash, but game reviews fail to identify those games with a higher likelihood of inducing them. It would be very beneficial to readers if games were evaluated on this risk. Applications exist that scan images to find those with the potential to provoke seizures.
For more than 30 years game manufacturers have been acknowledging the seizure risk by routinely slapping a warning on their games. This protects the studios from legal action and allows them to continue producing images that can be a serious health threat. Including seizure risk in reviewers’ rating criteria would certainly encourage game developers to adhere to seizure reduction guidelines established for visual media.
Not every game contains image sequences that could provoke a seizure. But since all games carry the seizure warning, those consumers who know about the risk have no way to know before using/buying whether a particular game contains images likely to cause them a problem.
Regrettably, most consumers still have little awareness of the seizure risk from flashing graphics or that regardless of whether there’s a seizure history. People with this genetic vulnerability (photosensitive epilepsy) typically don’t realize they need to be cautious around particular visual stimuli, that is until they experience a seizure that’s noticeable enough to be identified. Most people don’t know—I certainly didn’t—that seizures don’t always look like a big event.
Seizures can go on for years before being identified. Certain populations—kids with ADHD or autism in particular—are at higher risk of seizures, and the symptoms caused by unidentified seizures in these kids can exacerbate and hide behind existing behavioral difficulties. Nobody is holding publishers accountable.
According to a Reddit post, a game that I’ve said “passed the seizure test” triggered a seizure. Recently the same game—Hearthstone—could have been implicated in a professional gamer’s seizure that happened during a live stream. What’s going on?
I write about games I’ve tested to alert readers to the games that don’t meet internationally recognized image safety guidelines. But I don’t want to create undeserved confidence that a game that passed the seizure test will be safe for anyone with photosensitive epilepsy.
Ian Hamilton, a user interface designer who specializes in and advocates for game accessibility, clarifies the role of testing this way:
“Passing the Harding test doesn’t mean that a game is safe. It means ‘reasonably safe’ because common triggers have been avoided. Something that gets a ‘pass’ can still absolutely cause seizures.”
I regularly write that your experience may differ, that I’m not trained in quality assurance, that I test excerpts of game play, and that health and lifestyle variables affect every individual’s vulnerability to seizures at any given time. Still, the meaning of my findings could be misleading without an understanding of the limitations of the seizure test itself:
- the pass/fail guidelines aren’t expected to prevent seizures in all individuals
- the test was designed for TV images, not video games
What the Pass/Fail guidelines mean
The guidelines originated in 1994, when the UK’s agency for regulating TV broadcasting (now known as Ofcom) inserted into its code of standards some technical guidelines to accommodate viewers with photosensitive epilepsy. These guidelines, based on studies of photosensitive epilepsy and consultation with Prof. Graham Harding and other photosensitive epilepsy experts, detail flash rates and spatial patterns that typically trigger seizures in people with photosensitive epilepsy. Specifications regarding saturated red images were added later, after the 1997 Pokémon incident in Japan.
Some compromises in the guidelines were made for the sake of practicality. Criteria for acceptable images (commonly referred to as the Harding test) were developed with the understanding that they would realistically protect most individuals with photosensitive epilepsy, but not all. For example, the guidelines permit images that flash at a rate of up to 3 times per second because flash at that frequency affects only 3 percent of photosensitive individuals. UK regulators decided that was “an acceptably small risk.”
The introduction to the guidelines states that their purpose is “reducing the risk of exposure to potentially harmful stimuli.” It also concedes that even when broadcasting images that comply with the guidelines,
“it is…impossible to eliminate the risk of television causing convulsions in viewers with photosensitive epilepsy.”
Applying TV guidelines to video games
There are no formal guidelines for reducing the seizure risk from video games. A 2005 consensus paper by experts on photosensitive seizures acknowledges that additional work would be required first on the existing guidelines for TV. In the meantime, it is reasonable to use the television guidelines since the impact of screen images on the visual system is the same.
The biggest challenge in applying TV specifications to video games is explained in the consensus paper:
“These principles are easier to apply in the case of fixed media (for example, a prerecorded TV show), which can be analyzed frame-by-frame. Interactive media, such as video games, may afford essentially limitless pathways through the game, depending on user actions. Therefore …in the case of video games, the consensus recommendations apply to typical pathways of play but cannot cover every eventuality of play.”**
Reducing risk going forward
In sum, a game that fails the Harding test is best avoided by those with photosensitive epilepsy. A game that passes is less likely to act as a trigger. Despite all the qualifiers, I believe there’s value in reminding people that seizures can happen to anybody, that certain video games can trigger them, and that you can lessen the risk by selecting games without lots of flash and patterns. Other strategies to lessen the risk of photosensitive seizures can be found here and here.
Tip of the hat to Ian, who suggested that I avoid the word “safe” when describing games that have passed the test. I also will be revising my prior posts to do some rewording.
Gamer’s seizure on live stream
Here’s a reminder that seizures can happen to anyone. A professional gamer known as Lothar had a seizure recently during his live feed while playing Hearthstone on Twitch. Lothar apparently has no history of seizures and the seizure may or may not have any connection to Hearthstone. In updates about his condition and hospital stay, Lothar didn’t mention photosensitive epilepsy nor has he said he’s been advised to limit his gameplay.
For the record, Lothar is also a body builder—he’s obviously a guy who has enjoyed good health and takes good care of himself. Lothar has a large and caring following and has been receiving lots of well wishes as he recovers. Why do I mention this incident here? Viewing the incident (you can find it on YouTube) and seeing how it affected so many fans who care about him reinforced for me the seriousness of seizures and the importance of preventing those that are preventable.
Wouldn’t it feel terrible to give someone a present that could set off an epileptic seizure? If you consult the CNET guide to video games for 2015 holiday giving, you’ve got 8 games to choose from–of which 7 contain seizure-inducing images. In the 3+ years that I’ve been testing selected video games for seizure-provoking graphics, this is easily the most lopsided result I’ve found.
The following table shows the games recommended in CNET’s “The best video games to give this holiday season” feature, with results of testing them for image sequences capable of triggering seizures. Testing is done with an application designed for this specific purpose (more info on that is below in the testing methdology section).
Interpreting the results
Passing the seizure test means that in the 1.5+ hours of gameplay and cutscenes I tested, all image sequences meet well-defined guidelines for preventing visually induced seizures. I am not set up to test every possible sequence (video game developers should be able to do this, though). To get a “fail” on my tests, all that’s needed is one violation of the guidelines, which could occur within the space of a second or two. Again, since I do not test every possible sequence, it’s very possible–and likely–that the game also has other problem images that I didn’t test.
Your results may be different. Each person’s seizure threshold can be affected by a number of factors apart from the visual stimulus itself: illness, hunger, stress, fatigue, alcohol, medications, length of play, and others. So a game played without incident may trigger a seizure in the same player under different conditions. Also, players can be exposed to new and different image sequences in subsequent games.
CNET selected conventional action/adventure titles for its gift-giving guide. These games typically have plenty of shooting, explosions, and rapid movements that produce flicker in the seizure-inducing range of more than 3 flashes per second. In contrast, recent video game recommendations from both the New York Times and Los Angeles Times, with less tech-focused audiences, added some unconventional titles to their top picks. It’s worth noting that the less traditional games were less likely to fail the seizure test.
Uncharted: The Nathan Drake Collection–the one game CNET chose that passed the seizure safety test–is an action/adventure game, too, with some shooting and the occasional explosion, but designed without flickering images or other visual overload.
Why it matters
Nobody wants to think about the risk of seizures that can be triggered by video games, figuring they’re extremely rare (they aren’t) and that the risk only applies to “people with epilepsy” (not so). Also, people assume that seizures are always of the grand mal type, with loss of consciousness, lots of involuntary movements, etc., so that they would be very obvious events (most seizures are not like this).
If you assume seizures are very obvious, then you also assume you’d hear a lot more about seizures that happen in front of computer screens and consoles. But many seizures are much more subtle, some so subtle that nobody realizes they’re happening. Even in these instances, though, the after-effects may mean impaired functioning for up to several days, or longer, affecting energy, concentration, memory, sleep, and mood. You can read here about how game-induced seizures we couldn’t see affected my daughter.
Vulnerability to seizures from bright flashes and rapid flicker, known as photosensitive epilepsy, is a genetic trait that’s latent in an unknown percentage of the population. This means that there are people with no idea they have this sensitivity to visual stimuli–until they are triggered and experience a noticeable seizure. So these people assume the seizure warnings accompanying video games don’t apply to them, or they just ignore them.
Testing tool and methodology
I run downloaded gameplay clips, cinematic clips, and promotional trailers for each game and submit the sequences to 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. I don’t know how many of the major game developers in this country use the FPA–they keep such information very much to themselves.
The analyzer examines video sequences for very specific and measurable image qualities that researchers have found can trigger seizures:
- 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
If the first clip I test of a game fails the seizure guidelines test, I then move on to test the next game. If no guideline violations are found, I typically test at least 4 or 5 additional clips of that game–usually more, if I have a hunch due to the game genre and/or overall look of the sequences that there might be unsafe “footage” that I haven’t yet found. Most image sequences that fail the test do so because of strobe-like flicker.
Games that pass could have seizure-provoking sequences that I was unable to locate. I don’t do this testing while actually playing video games. Instead I work with video clips available online, some of which are official marketing and gameplay trailers; others are cutscenes and gameplay sessions posted by reviewers or fans. I avoid testing any clips of gameplay that were made using modifications to the original game software.
Other games I tested in 2015
This year I’ve tested also tested some other highly praised video games for their seizure risk (plus the games recommended by the New York Times and Los Angeles Times as noted above). Those results are here and here.