Dennō Senshi Porygon is an episode infamous for using visual effects that caused seizures in a substantial number of Japanese viewers, an incident referred to as the "Pokémon Shock" (ポケモンショック Pokémon Shokku) by the Japanese press. Six hundred and eighty-five viewers were taken to hospitals; two people remained hospitalized for more than two weeks. Due to this, the episode has not been rebroadcast worldwide.
"Dennō Senshi Porygon" aired in Japan on December 16, 1997 at 6:30 PM Japan Standard Time. The episode, which was broadcast over thirty-seven TV stations that Tuesday night, held the highest ratings for its time slot, and was watched by approximately 26.9 million households.
Twenty minutes into the episode, there is a scene in which Pikachu stops vaccine missiles with its Thunderbolt attack, resulting in a huge explosion that flashes red and blue lights. Although there were similar parts in the episode with red and blue flashes, an anime technique called "paka paka" made this scene extremely intense, for these flashes were extremely bright strobe lights, with blinks at a rate of about 12 Hz for approximately four seconds in almost fullscreen, and then for two seconds outright fullscreen.
At this point, viewers started to complain of blurred vision, headaches, dizziness and nausea. Some experienced seizures, blindness, convulsions and loss of consciousness. Japan's Fire Defense Agency reported that a total of 685 viewers - 310 boys and 375 girls - were taken to hospitals by ambulances. Although many victims recovered during the ambulance trip, more than 150 of them were admitted to hospitals. Two people remained hospitalized for more than two weeks. Some other people had seizures when parts of the scene were rebroadcast during news reports on the seizures. Only a small fraction of the 685 children treated were diagnosed with photosensitive epilepsy.
Later studies showed that 5-10% of the viewers had mild symptoms that did not need hospital treatment. 12,000 children who did not get sent to hospital by ambulance reported mild symptoms of illness; however, their symptoms more closely resembled mass hysteria than a grand mal seizure. A study following 103 patients over three years after the event found that most of them had no further seizures. Scientists believe that the flashing lights triggered photosensitive seizures in which visual stimuli such as flashing lights can cause altered consciousness. Although approximately 1 in 4,000 people is susceptible to these types of seizures, the number of people affected by this Pokémon episode was unprecedented.
After the airing of "Dennō Senshi Porygon", the Pokémon anime went into a four month hiatus until it returned in April 1998. After the hiatus, the time slot changed from Tuesday to Thursday. The opening theme was also redone, and black screens showing various Pokémon in spotlights were broken up into four images per screen. Before the seizure incident, the opening was originally one Pokémon image per screen. Before the resumption of broadcast, "Problem Inspection Report on Pocket Monster Animated Series" (アニメ ポケットモンスター問題検証報告 Anime Poketto Monsutā Mondai Kenshō Hōkoku) was shown. Broadcast in Japan on April 16, 1998, a woman named Miyuki Yadama went over the circumstances of the program format and the on-screen advisories at the beginning of animated programs. Many Japanese television broadcasters and medical officials got together to find ways to make sure the incident was not repeated.
They established a series of guidelines for future animated programs, including:
a more lengthy full article can be found here: http://en.wikipedia.org/wiki/Dennō_Senshi_Porygon
Action starts at 1:06..
"Dennō Senshi Porygon" aired in Japan on December 16, 1997 at 6:30 PM Japan Standard Time. The episode, which was broadcast over thirty-seven TV stations that Tuesday night, held the highest ratings for its time slot, and was watched by approximately 26.9 million households.
Twenty minutes into the episode, there is a scene in which Pikachu stops vaccine missiles with its Thunderbolt attack, resulting in a huge explosion that flashes red and blue lights. Although there were similar parts in the episode with red and blue flashes, an anime technique called "paka paka" made this scene extremely intense, for these flashes were extremely bright strobe lights, with blinks at a rate of about 12 Hz for approximately four seconds in almost fullscreen, and then for two seconds outright fullscreen.
At this point, viewers started to complain of blurred vision, headaches, dizziness and nausea. Some experienced seizures, blindness, convulsions and loss of consciousness. Japan's Fire Defense Agency reported that a total of 685 viewers - 310 boys and 375 girls - were taken to hospitals by ambulances. Although many victims recovered during the ambulance trip, more than 150 of them were admitted to hospitals. Two people remained hospitalized for more than two weeks. Some other people had seizures when parts of the scene were rebroadcast during news reports on the seizures. Only a small fraction of the 685 children treated were diagnosed with photosensitive epilepsy.
Later studies showed that 5-10% of the viewers had mild symptoms that did not need hospital treatment. 12,000 children who did not get sent to hospital by ambulance reported mild symptoms of illness; however, their symptoms more closely resembled mass hysteria than a grand mal seizure. A study following 103 patients over three years after the event found that most of them had no further seizures. Scientists believe that the flashing lights triggered photosensitive seizures in which visual stimuli such as flashing lights can cause altered consciousness. Although approximately 1 in 4,000 people is susceptible to these types of seizures, the number of people affected by this Pokémon episode was unprecedented.
After the airing of "Dennō Senshi Porygon", the Pokémon anime went into a four month hiatus until it returned in April 1998. After the hiatus, the time slot changed from Tuesday to Thursday. The opening theme was also redone, and black screens showing various Pokémon in spotlights were broken up into four images per screen. Before the seizure incident, the opening was originally one Pokémon image per screen. Before the resumption of broadcast, "Problem Inspection Report on Pocket Monster Animated Series" (アニメ ポケットモンスター問題検証報告 Anime Poketto Monsutā Mondai Kenshō Hōkoku) was shown. Broadcast in Japan on April 16, 1998, a woman named Miyuki Yadama went over the circumstances of the program format and the on-screen advisories at the beginning of animated programs. Many Japanese television broadcasters and medical officials got together to find ways to make sure the incident was not repeated.
They established a series of guidelines for future animated programs, including:
- Flashing images, especially those with red, should not flicker faster than three times per second. If the image does not have red, it still should not flicker faster than five times per second.
- Flashing images should not be displayed for a total duration of more than two seconds.
- Stripes, whirls and concentric circles should not take up a large part of the television screen.
a more lengthy full article can be found here: http://en.wikipedia.org/wiki/Dennō_Senshi_Porygon
Action starts at 1:06..
