The Indiana Gaming Commission told casino licensees on Tuesday to shut off selected Konami Gaming Inc. slots. As of Wednesday, officials had not decided whether to allow the devices to return to service.

Although there are relatively few Konami slots at Indiana casinos, the move was a precaution to protect patrons, said Jennifer Arnold, the commission's deputy director and spokeswoman.

"Based on what we knew, we thought it would be the prudent thing to do to pull the machines, at least until we know more," Arnold said. "It's likely we will not allow those machines to go back into service."

The issue arose last week after the Canadian Broadcasting Co. reported that four video slot games -- Most Wanted, Sergeant Fritter, Billionaires and Sticks and Stones -- featured symbols that for a fraction of a second align like a winning jackpot.

The CBC used slow-motion video to show that the symbols flashed too quickly for players to be aware of them. But psychologists said the flashes could be detected by the brain, the report said.

After the report, the Ontario Lottery and Gaming Corp. pulled 87 Konami machines out of service.

Konami said the flashes were a technical problem that it was fixing, according to the report. But its executives released a statement saying they also intend to take legal action against the CBC.

Konami did not return calls to its Las Vegas headquarters yesterday.

Sol Boxenbaum, a Montreal gambling critic and activist, said the CBC report raised a legitimate question about whether the machines give players the misleading impression that they're about to win. He also said the report shows the need for tighter scrutiny of evolving gaming technology.

"The machines now are meeting the industry standards," Boxenbaum said. But he said the public knows little about how the industry and regulators are policing the technology.

Some of the Canadian machines were examined over the weekend by officials of New Jersey-based Gaming Laboratories International, which tests slot technology and table games under contract with the Indiana commission and several other states.

The testing found that a line of symbols is displayed for a split second at the start of the round after a player activates the machine with the push of a button. But there is no subliminal message in that, said James Maida, president of Gaming Laboratories.

"It's been completely overblown," Maida said.

Indiana regulators acted after an inquiry by The Courier-Journal.

Arnold said the commission learned that Konami had sent a letter to alert regulators about the matter, but it went unnoticed for a day or two because it was addressed to the agency's former executive director.

Commission records indicate that five of Indiana's 11 casinos have the Konami games. Caesars Indiana in Harrison County isn't among them.

Arnold said a limited number are owned by Grand Victoria Casino at Rising Sun in Ohio County, Casino Aztar at Evansville and Belterra Casino in Switzerland County. The other two casinos are in Northern Indiana.