Dennō Senshi Porygon

Ash, Misty, Brock and Pikachu discover that the system used to transfer Pokémon from one Pokémon Center to the other is malfunctioning. On Nurse Joy's request, they go to Professor Akihabara, the one who created the Poké Ball transfer system. He tells them that Team Rocket stole his prototype Porygon, a digital Pokémon that can exist in cyberspace, and is using it to steal trainers' Pokémon from inside the computer system.

Akihabara sends Ash, Misty, Brock, Pikachu and his second Porygon into the system to stop Team Rocket, whom they learn have set up a blockade that stops Pokéballs from traveling the network. Porygon is able to defeat Team Rocket's Porygon, but Nurse Joy, monitoring the situation and unaware that Ash and the others are inside, has sent an anti-virus program into the system to combat the computer virus Team Rocket set up. Pikachu uses a Thunderbolt attack on the program, which manifests as "vaccine missiles", which causes an explosion. The group and Team Rocket successfully escape the computer, and with Team Rocket's blockade removed, the system returns to normal.

"Dennō Senshi Porygon" aired once in Japan on December 16, 1997[1] at 6:30 PM Japan Standard Time (09:30 UTC).[2] It was broadcast over 37 TV stations that Tuesday night. It held the highest ratings for its time slot[2] and was watched by approximately 4.6 million households.[3][4]

Twenty minutes into the episode, Pikachu stops "vaccine" missiles with his Thunderbolt attack, resulting in an explosion that flashes red and blue lights.[1][5] Although there were similar parts in the episode with red and blue flashes, two anime techniques, "paka paka"[lower-alpha 1] and "flash"[lower-alpha 2] made the scene particularly intense.[6] These flashes were bright strobe lights, with blinks at a rate of about 12 Hz for approximately six seconds.[7]

At this point, some viewers experienced blurred vision, headaches, dizziness and nausea.[1][5][8] Some suffered seizures, blindness, convulsions and loss of consciousness.[1][5] Japan's Fire Defense Agency reported that 685 viewers – 310 boys and 375 girls – were taken to hospitals by ambulances.[5][9] Although many victims recovered during the ambulance trip, more than 150 were admitted to hospitals.[5][9] Two were hospitalized for more than two weeks.[9] Some had seizures when parts of the scene were rebroadcast during news reports on the seizures.[8] Only a small fraction of the 685 children treated were diagnosed with photosensitive epilepsy.[10] The incident was referred to as "Pokémon Shock" (ポケモンショック, Pokémon Shokku) by the Japanese press.[11]

Later studies showed that 5–10% of the viewers had mild symptoms that did not need hospital treatment.[7] Twelve thousand children who were not sent to hospital reported mild symptoms of illness; however, their symptoms more closely resembled mass hysteria than a grand mal seizure.[5][12] A study following 103 patients over three years after the event found that most had no further seizures.[13] 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 are susceptible to these types of seizures, the number of people affected by the Pokémon episode was unprecedented.[1][9]

An article in USA Today reassured parents that American children were unlikely to suffer seizures provoked by cartoons as US networks at the time rarely aired anime, with its "fast-paced style of animation",[14] though anime has since become more prevalent with the expansion of cable networks and streaming venues. The incident was included in the 2004 edition and the 2008 Gamer's Edition of the Guinness World Records book, holding the record for "Most Photosensitive Epileptic Seizures Caused by a Television Show".[15][16]

News of the incident spread quickly through Japan. The following day the television station that had originated the lone broadcast of that episode, TV Tokyo, issued an apology to the Japanese public, suspended the program, and said it would investigate the cause of the seizures.[5] Officers from Atago Police stations were ordered by Japan's National Police Agency to question the anime's producers about the show's contents and production process.[6] An emergency meeting was held by the Ministry of Health, Labour and Welfare, in which the case was discussed with experts and information collected from hospitals. Video retailers all over Japan removed the Pokémon anime from their rental shelves.[5]

Reaction was swift on the Tokyo Stock Exchange, and Nintendo's shares fell by 400 yen (almost 5%) the following morning to 12,200 yen.[5][17] Nintendo produces the game upon which the Pokémon anime series is based. Then-president of Nintendo, Hiroshi Yamauchi, said at a press conference the day after the episode had aired that the video game company was not responsible since the original Pokémon game for its Game Boy product was presented in black and white.[17][18]

After the airing of "Dennō Senshi Porygon", the Pokémon anime went into a four-month hiatus, removing the TV Tokyo red circle logo and the チュシ! text from the Japanese anime, Pokémon Season 1: Indigo League Opening Credits & Ending Credits, The opening animation was redone, The lightining flash has been removed from the Dare da? segment, and rerun all 37 episodes of Pokémon Season 1: Indigo League on Kids Station in Tokyo, Japan, and they show the EP039 Pikachu's Goodbye Preview, until it returned on April 16, 1998 with airing of "Forest of Pikachu" ("Pikachu's Goodbye") and "The Four Eievui Brothers" ("The Battling Eevee Brothers").[19][20] After the hiatus, the time slot changed from Tuesday to Thursday.[3] The opening theme was also redone, and black screens showing various Pokémon in spotlights were broken up into four images per screen and at the end of the opening animation, they show just the テレビ東京 text logo without the TV Tokyo red circle logo and without the チュシ! text. The Dare da? segment was also redone, it starts on the black screen without the lightning flash, and it continues on the blue screen without the lightning flash. Before the seizure incident, the opening was originally one Pokémon image per screen, the end of the opening animation was showing TV Tokyo red circle logo and the チュシ! text, the Dare da? segenent still has the lightning flash.[3] 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, host Miyuki Yadama went over the circumstances of the program format and the on-screen advisories at the beginning of animated programs, as well as showing letters and fan drawings sent in by viewers, most of whom were concerned that the incident would lead to the anime being cancelled.[3] Many Japanese television broadcasters and medical officials (along with the ITC of the UK) came together to find ways to make sure the incident was not repeated. They established a series of guidelines for future animated programs,[9][21] 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.

This episode kept the episodes "Rougela's Christmas" ("Holiday Hi-Jynx") and "Iwark as a Bivouac" ("Snow Way Out!") off their original broadcast date in Japan following the incident. Those two episodes were about to air after "Dennō Senshi Porygon" on December 23, 1997 and January 6, 1998 respectively. They were eventually only aired on October 5, 1998 as an hour-long special. Airing out of order caused confusion to viewers because Ash still had a Charmander instead of Charizard, and Misty did not have Togepi yet, but Starmie and Horsea. Also, a New Year special was about to air between these episodes on December 30, 1997, but it was cancelled after TV Tokyo pulled any mention of Pokémon from their channel following the incident.

To prevent any similar incidents from occurring, Nintendo quickly ordered the episode pulled, and it has not aired since in any country.[1][22] After the Pokémon incident, TV broadcasters voluntarily added on-screen warnings to shows targeted at young children encouraging viewers to watch anime in a well-lit room and to sit far away from the television set.[23] In an effort to put the event out of public concern and prevent victims from reliving the traumatizing event, the anime has not featured Porygon or its evolutions in any subsequent episodes.[24]

The "Pokémon Shock" incident has been parodied many times in popular culture, including an episode of The Simpsons, "Thirty Minutes over Tokyo". In the episode, the Simpson family travels to Japan. When they arrive at their hotel in Tokyo, Bart is seen watching an anime entitled Battling Seizure Robots featuring robots with flashing eye lasers, and asks: "Isn't this that cartoon that causes seizures?", and the flashing eyes cause him to have a seizure. Marge and Lisa are also affected and Homer walks in seeing them all convulsing on the floor and joins in. The same scene is seen again in the episode's end credits, this time covering the entire screen.[20]

An episode of South Park that first aired in November 1999, "Chinpokomon", revolves around a Pokémon-like phenomenon, called Chinpokomon, with which the children of South Park become obsessed. Chinpokomon toys and video games are sold to American children in South Park by a Japanese company. The company's president, Mr. Hirohito, uses the toys to brainwash the American children, making them into his own army to topple the "evil" American "empire". These toys included a video game in which the player attempts to bomb Pearl Harbor. While playing this game, Kenny has an epileptic seizure and later dies, in reference to the Pokémon seizure incident.[20]

In the pilot episode of Drawn Together, Ling-Ling, who is a parody of Pikachu, states that his goal in the Drawn Together house is to "destroy all, and give children seizures". There follows a scene with flashing lights.[25]

In So Yesterday, a novel by Scott Westerfeld, this episode is mentioned and shown to one of the characters. The flashing red light that caused the seizure is also used in the story telling elements.[26]

• List of Pokémon episodes
• Pokémon episodes removed from rotation — information on other Pokémon episode controversies
• YAT Anshin! Uchū Ryokō controversy — a similar incident

• "Dennō Senshi Porygon" at TV.com
• "Dennō Senshi Porygon" on IMDb