A watchdog group is calling on the Ontario gambling regulator to launch a review of slot machines across the province after findings that several types of machines flashed subliminal jackpot messages, but the regulator says that's not their job.

Three types of slot machines built by the same company, Konami, were pulled from Ontario casinos after a CBC investigation revealed the games flashed a line of jackpot symbols every two seconds.

The winning images appear for a fifth of a second, but psychologists say it's enough for the brain to detect even if players are not conscious of the message.

'The likelihood of an error by chance producing a winning combination of the jackpot symbols is extremely low, maybe 100,000 to one.'—Mathematics Prof. Kevin Carrigan

Brian Yealland of the watchdog group Gambling Watch wants the Alcohol and Gaming Commission of Ontario (AGCO) to conduct a comprehensive review of the machines' internal programming — "a review of every slot machine that exists in the province of Ontario from the point of view of is this a safe product? Does it meet the letter of the law from the point of view of the protection of the consumer, fair practice?"

AGCO to seek advice on subliminal messages

Claims by slot machine maker, Konami, that the flashing jackpots are unintentional have been greeted with skepticism by some.

"The likelihood of an error by chance producing a winning combination of the jackpot symbols is extremely low, maybe 100,000 to one," Kevin Harrigan, a mathematics and computer professor at the University of Waterloo, told CBC News.

Computer specialists say the only way to really know if it was intentional is for testers to examine each line of programming code inside the machines.

The AGCO has no plans to do that, saying they are comfortable with the manufacturer's explanation it was a computer glitch.

Ab Campion, spokesman for the commission, also says they don't have the facilities to test the machines, and so rely instead on the good faith of slot machine manufacturers.

However, the AGCO has decided to seek independent advice on whether subliminal messages can pose a risk to gamblers.

From now on, all game suppliers will be asked to sign a guarantee that their machines don't contain any hidden jackpot messages.

The Konami games pulled in Ontario are Most Wanted, Sergeant Fritter and Billionaires.