Graham Harding, 1937 – 2018

charles at aston2

Prof. Harding hosted Prince Charles at the opening of the new Vision Sciences Department building at Aston University in November 1987.

Prof. Graham Harding, a pioneer in photosensitive epilepsy research, has died at age 81. His recent obituary in The Times aptly described him as a world authority on photosensitive epilepsy. Prof. Harding published more than 350 research papers and co-authored a seminal book on photosensitive epilepsy. He was among the first to recognize the risk of seizures from television and video game graphics.

Perhaps most important of all, he crafted image guidelines that reduce the public’s risk of photosensitive seizures from environmental triggers, and he advocated for safer video games. His own research and studies by others showed that specific, measurable qualities of a flashing or patterned image determine its risk of triggering epileptic seizures in individuals with photosensitive epilepsy.  Identifying the risk factors and danger thresholds from the flash interval, and the brightness, size, and color contrast of images enabled him to create guidelines for minimizing the chances of seizures.

The need to protect the public 

In 1993, flashing images in a commercial on British TV caused seizures in three viewers the first time it aired. In response, the British regulatory agency for television asked Prof. Harding to draft guidelines to limit the public’s exposure to seizure-provoking television images. Four years later, after the Pokémon incident in Japan, the Japanese government asked him to do the same.

Nearly 700 children had arrived at hospitals in Japan for suspected seizures during a Pokémon cartoon broadcast. Prof. Harding later recalled in an interview, ‘The first I knew of it was when my secretary said, ‘The Japanese embassy is on the phone, 400 children have just had seizures,”’ and shortly afterward he was flown to Japan. Doctors found that 560 of the children had probably experienced seizures; 76 percent of them had never had a seizure previously.

Practical solutions

Prof. Harding was clear that seizure warnings on video game packaging and instructions do not provide adequate protection for consumers, citing the 76 percent of Japanese children whose first seizure occurred during the Pokémon cartoon.

While Nintendo, for example, warns that anyone who has had a seizure induced by flashing lights or patterns should consult a doctor before playing a video game, Harding said, that doesn’t protect against a first attack. ″Warnings are good except for people who don’t know they are photosensitive,″ said Harding.

Knight-Ridder Newspapers, December 25, 2002

Ensuring that the guidelines were observed was very time-consuming; he analyzed broadcast video images frame by frame. “Some days I spend four to five hours watching the television,” he said at the time. “It is nice in that it is real applied medical science. Part of my job is stopping people having seizures, so if this is how I do that I don’t really mind.”

With the help of his wife and Cambridge Research Systems, Ltd. he then created the Harding Flash and Pattern Analyzer (FPA) to automate the process, which was nominated for a Royal Television Society technical innovation award in 2001. I have used the FPA many times to check images of video games and music videos.

Harding and Jeavons book cover tiny

Prof. Harding co-authored the first monograph on photosensitive epilepsy in 1975.

Other accomplishments

Prof. Harding received his PhD at the University of Birmingham in electroencephalography (EEG) and psychiatry. He spent 40 years at Aston University in Birmingham, where he headed up the Vision Sciences Department and was the first professor of clinical neurophysiology in the UK. When the department opened a new building in 1987, Prof. Harding hosted the Prince of Wales at the opening ceremony. Although he did not have medical credentials, his contributions to medicine were recognized with membership and then fellowship in the Royal College of Physicians.

Prof. Harding was also one of the developers of guidelines to standardize photic stimulation testing, a diagnostic procedure for identifying photosensitivity, and he wrote about the risk of photosensitive seizures precipitated by wind turbines.

It is hard to overstate Prof. Harding’s influence on the study, diagnosis, and prevention of visually induced seizures.

Selected papers

Televised Material and Photosensitive Epilepsy

Regulations: What Next?

Persistence of Photosensitivity

Characterizing the Patterned Images that Precipitate Seizures and Optimizing Guidelines to Prevent Them

Photic- and Pattern-induced Seizures: Expert Consensus of the Working Group of the Epilepsy Foundation of America Working Group

Wind Turbines, Flicker, and Photosensitive Epilepsy

 


Fortnite: The game–and the seizures–are free

Fortnite’s High Explosives mode fills large areas of the screen with bright, rapidly moving images that can trigger seizures.

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.

A Fortnite “high explosives” weapon in action

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.

Problem flash isn’t limited to explosions. The flash in this sequence came from spacecraft lights.

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.


Seizures from 2017’s best video games

What Remains of Edith Finch, Gorogoa, Everything, Night in the Woods, Divinity: Original Sin 2, Legend of Zelda: Breath of the Wild, PlayerUnknown's Battlegrounds, NieR:Automata, Persona 5, Super Mario Odyssey

The New Yorker’s Top 10 video games of 2017. Five contain scenes that could trigger 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?

Resident Evil 7, Horizon Zero Dawn, Wolfenstein 2: The New Colossus, Hellblade: Senua's Sacrifice

GameSpot’s 2017 Top 10 list includes 6 games that contain images that can trigger 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.

Screen grab from a sequence in The Legend of Zelda that could provoke a seizure in individuals with photosensitive epilepsy.

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.

For more specifics on how to interpret the test results, please see this prior post. For more on my testing process, see this one.


Fidget spinners can trigger seizures

Local TV news ran a feature on seven-year-old Khloe of Aiken County, SC after she experienced a 30-minute seizure triggered by a fidget spinner. She’d never had a seizure before. The spinners, the latest craze in toys/gadgets, have already drawn criticism because children can be injured by them or choke on the small parts, and because they create distractions in classrooms. Khloe’s experience demonstrates another reason to be wary of fidget spinners:  they create visual effects that can bring on seizures, even in people with no seizure history.

How does a spinner cause seizures?

When seen from close range, a rotating fidget spinner creates rhythmic visual effects that can cause a seizure.

Seizures induced by visual stimuli can be triggered in people with a condition known as photosensitive epilepsy. Typical triggers include rapidly flashing strobe lights, video games, and TV, as well as rotating helicopter blades and spoked wheels. Because rotating blades and spokes make rhythmic visual patterns where parts of the image rapidly alternate between light and dark, they can have a similar effect on the brain’s visual cortex as flashing lights. Because photosensitive epilepsy can emerge in people with no history of seizures, people may learn they have the condition only after experiencing a seizure.

Added risk from LED lights…

Strobing LED lights significantly boost the seizure-provoking visual effects of spinners. Watching in the dark boosts them further.

The risk of spinners triggering seizures is heightened by the flashing LED lights on some versions. Varleisha Gibbs, PhD, chair and director of the occupational therapy master’s program at Wesley College, expressed concern about this possibility in a May piece on Fatherly.com, “One of the triggers for seizure disorders is strobe lights…I would fear that could be a trigger.” Khloe’s seizure happened while she using a spinner with LED lights. She owns several others, without lights, that have not triggered seizures.

If kids turn out the lights to watch the spinner flashing in the dark, the strobing lights create even more of a seizure risk because of the contrast in brightness between the LEDs and the surrounding darkness.

The strobing effect of an LED spinner in motion captured on video. The frames shown here represent approximately half a second in real time.

Should I be concerned even if my child isn’t having seizures?

Your child could be having seizures you and the child aren’t aware of. Not all seizures involve convulsions, and many seizures aren’t noticed because their outward signs are subtle or simply not visible. Even if you can’t see them happening, seizures can leave your child with fatigue, confusion, mood problems, and other issues. We learned this after discovering that our daughter experienced unseen seizures while playing video games.

Vulnerable kids with ADHD and/or autism

The kids for whom these fidget spinners were initially intended to help (to increase focus, decrease anxiety) are probably more vulnerable than most other kids to visually induced seizures. Young people with ADHD and autism are more likely to have sensory processing issues that can include photosensitive epilepsy.

This frame was captured from the video clip about a seven-year-old’s seizure from her LED fidget spinner.

Note: Unfortunately, the WJBF TV news story about Khloe’s seizure, now posted on the station’s website and on YouTube, shows close-ups of the LED spinner in motion. Do not watch it if you are vulnerable to visually induced seizures! The clip includes images that exceed recommended limits on “safe” flash frequency. Watch anyway, at your own risk? Click here.

 


Kudos: Riot Games Pulls Problem Image Fast

Riot Games’ League of Legends

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:

  1. apologized
  2. took down and replaced the animated image
  3. announced the fix
  4. 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.”
  5. 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.

No violations of seizure reduction guidelines occurred when testing the League of Legends image.

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.

 

 

 

 


New York Magazine’s Top Ten Video Games? Half ignore seizure safety guidelines!

thumper

Thumper, #9 on New York Magazine‘s top ten games list, has many flashing images that could trigger seizures in users. The image here is seen during a sequence that failed the seizure guidelines compliance test.

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.

Thumper, Overwatch, Hyper Light Drifter, Uncharted 4: A Thief's End, Doom, Inside, Firewatch, Kentucky Route Zero Act IV, Owlboy, Overcooked

New York magazine’s top ten video games for 2016

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

Want to know more about how I test video games? Read here. Or read more about the image safety guidelines.


5 top first person shooter games of 2016 fail seizure safety guidelines test

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:

2016-top-5-shooter-games

Forbes’ Best 5 First-Person Shooter Games of 2016 all failed to adhere to guidelines for reducing seizures.

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 

This bright flash is seen during a Doom image sequence that fails to meet seizure reduction guidelines.

This bright flash is seen during a DOOM image sequence that doesn’t meet seizure reduction guidelines.

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

A problem sequence in Call of Duty: Infinite Warfare is created by a flicker effect of changing background light in this scene.

A problem sequence in Call of Duty: Infinite Warfare is created by the flicker effect of alternating background light in this scene.

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.

Reason #3

When the area on the screen lit by a flash and the time interval between flashes exceed guidelines for seizure reduction, the image sequence fails the assessment. This screen shows test results for Titanfall 2.

This screen capture from the Harding Flash and Pattern Analyzer, which I used to assess guidelines compliance, shows test results above the horizontal pass/fail line.

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.)

Also…

  • 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.