Therapeutic clowns seem to have the ability to reach unresponsive children disabled by brain injuries or cerebral palsy, a unique Canadian study suggests.

Therapeutic clowns are designed to engage children, but there had yet to be a scientific study into their physiological effectiveness.

In the new study, researchers at Bloorview Kids Rehab in Toronto, gauged the physical responses of eight unresponsive children while they viewed television and when they were visited by the therapeutic clowns.

"We don't know how to get into their world, and there are very few things that happen in their lives that we can objectively study," researcher Stefanie Blain said of the children.

The eight children used in the study had conditions that included severe cerebral palsy, traumatic brain injury and stroke. Five of the eight could speak, express emotion through facial expressions and point; two were non-verbal but could show facial emotion; and one was non-verbal and unable to gesture or use facial expression.

So the researchers used heart monitors, bands to measure skin temperature and sweat level and gauges worn around the chest to track breathing.

On alternate days, the children watched 10 minutes of a television show. On the other days, they had 10-minute visits with two clowns named Ricky and Dr. Flap, who used physical and emotional comedy and music.

To their surprise, the researchers found that the children were largely unresponsive to television but were excited by the clown's presence.

Their skin, heart and breathing signals were either pulled out of resting states or the pattern of the four signals changed when the children were visited by the clowns.

"They were having a huge reaction to what was going on around them even though you couldn't see it with the naked eye, it was super exciting because it validated there was a person inside," Shauna Kingsnorth, a postdoctoral fellow Bloorview and the study's lead author, told CTV News.

The findings were collected and published online in the journal Evidence-based Complementary and Alternative Medicine.

Medical therapeutic clowns reacted with excitement to the study.

"We didn't know for sure [that they were reacting] and now that we are hearing that there is a reaction, it's amazing," Helen Donnelly said.

"If we can be used as a tool to find out more information about how these kids communicate . . . we welcome that," added Jamie Burnett, a therapeutic clown who has been at Bloorview for several years.

With a report from CTV medical specialist Avis Favaro and producer Elizabeth St. Philip