A choir of Canadians with Parkinson's disease is helping researchers test how well the performers regain facial movement to express emotions.

Tremors and difficulty walking are often the most noticeable symptoms of Parkinson's disease, which affects about one in 500 people in Canada. Those with the disease may also have limited facial movement, which hampers the ability to express themselves.

For people with Parkinson's who have "masked face syndrome," it can be difficult for others to decipher how they're feeling. That's because we unknowingly mimic or mirror each other during interaction to connect.

"Within a hundred milliseconds of seeing someone else smile or frown, we are smiling or frowning," said Frank Russo, a psychology professor at Ryerson University in Toronto. "We're mirroring what the other person is doing. And that's one of the things that is absent in Parkinson's. It's the absence of mirroring that is leading to some of the deficit in understanding other people's emotions."

Bonnie Le Lyons-Cohen

Bonnie Le Lyons-Cohen, right, sings in a choir whose members all have Parkinson's disease. She says the experience has helped her confidence. (CBC)

Having a static face can leave people with Parkinson's seem cold and aloof as they also show deficits in understanding other people's emotions. The patient can then become emotionally disconnected from others.

Studying the 28 members of the Parkinson's choir has bolstered Russo's thinking that singing, facial expressions and social communications are interconnected.

So far Russo has found that mirroring effect or mimicry was restored among choir participants who sang for 13 weeks.  

"We are facilitating exercise of the facial muscles and the vocal muscles. It's through this experience expressing ourselves in emotional communication that we are better able to understand other people's emotions."

The Toronto researchers say their project is the first to look at emotional mimicry in the context of singing. Other Parkinson's choirs exist for a different focus, such as restoring breath support.

Singer Bonnie Le Lyons-Cohen, 58, said participating in the choir has been a life-changing experience. Previously she tended to look down and freeze.

"It's made a big difference, first of all my confidence," she said. "Now I look up and I sing. If people aren't understanding me I just project my voice a little bit louder."

Lyons-Cohen said she's regained the ability to modulate her voice while enjoying hanging out with other members of the choir. 

The project ended last week but choir members hope to keep it going.

With files from CBC's Vik Adhopia