(CNN Belief Blog) -- A Vatican spokesman on Tuesday refuted claims that Pope Francis performed an exorcism on a man in St. Peter's Square after Mass on Sunday. But he did not altogether deny the encounter.
"The Holy Father had no intention to perform any exorcism," the Rev. Federico Lombardi said in a statement. "Instead, as he frequently does for the sick and suffering persons who approach him, he simply meant to pray for a suffering person who was presented to him."
Speculation that Francis performed an exorcism began to ricochet around the Internet when video of the encounter from TV2000, a Catholic television station in Italy, was posted online.
In the video, Francis smiles and takes the hand of an unnamed man in a wheelchair. After a priest whispers in the pope's ear, his demeanor changes and he places his hands on the man's head. The video shows the man in the wheelchair convulsing before his body goes limp with his mouth agape.
The pope also places his hands on two other people in wheelchairs, but neither has the same dramatic reaction.
Performing an exorcism is the act of "casting out" evil spirits from a person's body. The power to perform exorcisms, wrote the Rev. Thomas Rosica in an e-mail to reporters, "was conferred by Jesus on the apostles, and it is understood that this power passes to the bishops who are the successors to the apostles, and priests the co-workers."
"The Church has had -- for many hundreds of years, it ought to be added -- a very precise ritual of exorcism: there are no evangelical-style tent revival theatrics, but careful, even methodical attention and faithful following of the prescribed prayers, gestures and use of sacraments such as holy water and the crucifix," Rosica added.
Bishop Thomas J. Paprocki of Springfield, Illinois, an American expert on exorcism who organized a conference on the topic in 2010, said what Francis did on Sunday was "clearly not an exorcism as most people understand it."
"It is just too short," Paprocki said. Most exorcisms, Paprocki said, take 20 to 30 minutes to complete and involve reciting prayers, reading scriptures and using sacramental objects such as crucifixes and holy water.
"I doubt the pope has it memorized," the bishop said.
Paprocki's 2010 conference on exorcism was seen as a peak of interest in the ancient practice -- at least in the United States. According to experts, 100 bishops and priests attended the exorcism conference held in Baltimore.
"Since that conference, I think things have died down a little bit," Paprocki said. "I think it kind of ebbs and flows and sometimes you get more of an interest in that than other times."
Exorcism is not unique to Catholicism. Other Christian faiths, Hinduism and Islam all have forms of casting out evil spirits.
Jesus performs a number of exorcisms in the Bible, encounters that are recounted in the Gospels of Matthew, Mark and Luke. One example: in Matthew 9:32-34, Jesus exorcises a mute shortly after healing two blind men.
"As they were going away, behold, a demon-oppressed man who was mute was brought to him," reads the passage. "And when the demon had been cast out, the mute man spoke."
The guidelines on Catholic exorcisms, "De Exorcismis et Supplicationibus Quibusdam," or "Of Exorcisms and Certain Supplications," are an 84-page document that was last revised in 1998.
Hollywood has also contributed to the public fascination with exorcism.
In 1973 "The Exorcist" captured America's imagination about demons taking over a person's body and profoundly shaped the public's perceptions about the process of throwing those devils out. The movie was violent, vivid and for many people unforgettable.
More recently, in 2010, a movie titled "The Rite," starring Anthony Hopkins, dramatized the life and training of the Rev. Gary Thomas, a California priest, as an exorcist in Rome.
To experts on exorcism, however, these movies are just a sensational look at a traditional Catholic practice.
"These portrayals in these movies tend towards sensationalism," said Rev. Mark Morozowich, dean of theology and religious studies at the Catholic University of America. "It creates a hysteria among some people and it creates fantasies among other people. I think this has caused undue fascination with these things."
Morozowich said in some cases exorcisms are legitimately necessary and solemn tasks taken on by a priest.
"While possessions do exist, they are meant to be something more private," Morozowich said. "Sometimes it trivializes that experience by fantasizing it."