A new study shows that interacting with a cute and cuddly robotic seal called Paro can actually reduce the perception of pain.

Created in Japan more than 15 years ago, Paro is a robotic baby harp seal designed as a therapeutic tool for use in hospitals and nursing homes.

The robot is programmed to cry for attention and respond to its name. It’s cute, it’s cuddly, it wiggles and has comforting noises – making it an ideal companion.

Several international studies have shown that Paro can reduce stress and anxiety and improve mood, particularly in older adults with dementia.

More recently, researchers in Israel have been exploring Paro’s effect on physical pain.

Nirit Geva, Dr Florina Uzefovsky and Dr Shelly Levy-Tzedek at Ben-Gurion University of the Negev, in Israel, have published the results of the study in Scientific Reports measuring exactly how much Paro can help those experiencing pain.

During the study, the researchers subjected 83 participants to a spectrum of pain sensations ranging from “mild” to “strong.”

Some were allowed to see Paro while others were allowed to cuddle the seal. They then measured whether Paro was able to mitigate the pain.

Holding hands can reduce pain

Previous studies have shown that a pain sufferer’s pain is reduced if they’re holding hands with another person. So, is it the same if you’re holding a little seal robot?

The initial studies found that touching Paro does, in fact, reduce the perception of pain. Was the pain significantly less than if the robot wasn’t there?

During the experiment, heat-pain intensity was calibrated separately for each individual, and they were asked to rate how intense they felt like the pain was at several points.

One group did not get to interact with Paro at all. The others alternated between watching Paro from across the room during the experiment and “actively touching” Paro.

As well as recording the subjective pain measurement from each participant, the researchers also took samples of oxytocin, a hormone associated with social behaviour and bonding. Participants were also asked to fill out a questionnaire about what they were thinking and feeling.

Pain ratings

They rated their pain sensation as significantly lower when touching Paro robot in relation to their baseline pain ratings. The effect was most pronounced in the strong pain condition.

On those occasions, when touching Paro the amount of perceived pain was reduced from about a five (on the 1-10 scale) down to about a three.

However, when Paro was just in the room, pain levels were reduced minimally.

This implies that the distraction of a robot made people feel “a little better.”

Touching Paro also made people happier in general, highlighting the importance of wanted social touch. This same kind of pain reduction effect can be achieved when someone is holding hands with a partner, but not with a stranger.

Emotional connection

The researchers suggest that the robot is effective because “touching PARO enabled participants to form an emotional connection with it,” turning the robot into a more effective social agent than a stranger who is an actual human.

The results with the oxytocin were also interesting, the researchers say.

Oxytocin is a hormone they describe as “having a central role in mediating feelings of love, social attachment, and communication.” It has been shown that by increasing oxytocin, perceived pain can be lowered.

You could therefore assume that by cuddling Paro oxytocin levels increase, causing a decrease in perceived pain. But when the researchers measured oxytocin levels during the study, they found the opposite: Oxytocin levels decreased in people who touched Paro.

Dr Levy-Tzedek, head of the Cognition, Aging, and Rehabilitation Lab, thinks that this may have been because Paro significantly reduced stress, which also reduces oxytocin. This effect was most pronounced in participants who felt the strongest connection with Paro.

“It appears that those who felt they were able to communicate well with the robot (form a social connection with it) benefited more from the interaction, as they experienced a greater reduction in pain (which may be mediated by the reduction in oxytocin),” Dr Levy-Tzedek said.

Positive feedback from participants

In a recent interview with IEEE, Dr Levy-Tzedek, explained how she managed to convince young adults to take part in the experiment which involved some “strong pain.”

Strong pain is a 6+ out of 10 on a scale where 10 is “the most intense pain sensation imaginable.

However, Levy-Tzedek assured them the experience would not be “stressful or traumatic.”

The pain was generated for just a few seconds by a heating plate attached to the forearm, and the participants had direct control over not just stopping it but enabling an active cooling system to remove the heat as quickly as possible.

The feedback from participants about their experience was positive, she says.

“And many of them said (unprompted) they were willing to return for future experiments.”

Previous studies

The latest study confirms that Paro is becoming an increasingly useful medical tool on a number of levels.

A previous study with Paro showed that it reduced stress in children more when it was turned on rather than off. (Another study, with a different social robot, showed a reduction in cortisol levels in old adults in the on, and not in the off state).

A third study, with Paro, showed greater verbal and visual engagement levels with Paro in adults with dementia while the robot is operating.

Also, studies from human-human touch interactions show that the touch has to have a positive social meaning for it to be effective in reducing pain.

Dr Levy-Tzedek says based on the latest research, Paro could be used in other ways to help people.

For instance, it could be used to help manage pain and improve emotional state in young adults. It could also be potentially used for people with chronic pain to help improve the quality of life.

Dr Levy-Tzedek says the findings are particularly relevant during the current COVID-19 pandemic, when people are advised to keep a social distance from others – including family members and close friends.

When there is a reduction in the availability of close affective touch a social robot may help in this period, she says. 

Dr Levy-Tzedek says the research is continuing. So, watch this space.