Scientists have uncovered an ancient and elaborate source of pain relief that is based purely on the power of the mind, according to research published today.

Brain scans of volunteers who were subjected to electrical shocks revealed that Roman Catholics felt less pain than atheists and agnostics when they were shown a painting of the Virgin Mary.

Images of the volunteers' brains showed that in devout believers, an area of the brain that suppresses reactions to threatening situations lit up when they were shown the picture.

Researchers at Oxford University, led by Katja Wiech, recruited 12 nonbelievers and 12 practising Roman Catholic students. In the tests, participants were shown either an image of the Virgin Mary by the 17th-century Italian painter Sassoferrato or Leonardo da Vinci's 15th-century Lady with an Ermine. After looking at the picture for 30 seconds, the volunteers were zapped with electrical pulses for 12 seconds. Each time, they were asked to rank how painful the shocks were on a scale of zero to 100.

The researchers describe how Roman Catholics and nonbelievers reported similar levels of pain after viewing the Leonardo painting. But the two groups responded very differently to the Virgin Mary painting, with Catholics experiencing 12% less pain.

When Wiech's team looked at the brain scans of the two groups, they found marked differences between them. After seeing the Virgin Mary, an area in the brain called the ventrolateral prefrontal cortex lit up in the religious volunteers.

"The Roman Catholics engaged a brain mechanism that is well known from research into the placebo effect, analgesia and emotional disengagement," said Wiech. "It helps people to reinterpret pain, and make it less threatening. These people felt safe by looking at the Virgin Mary, they felt looked after, so the whole context of the test changed for them."

It is highly likely that non-religious people could achieve a similar ability to control pain, perhaps through meditation or other mental strategies. "There's no suggestion that this effect is specific to religion and we've not found the God blob in the brain. This is about the state of mind you can achieve," said Wiech.

Preliminary studies on lapsed Catholics suggest that images of the Virgin Mary lessen their sense of pain too, the researchers said.