Should you seek assistance from someone you know or from someone you don't?
Earlier this year, one study covered on Medical News Today showed that, just by touching someone we care about, we can relieve physical pain to a certain degree.
More recently, researchers from the University of Würzburg in Germany, the University of Amsterdam in the Netherlands, and the University of Zurich in Switzerland have conducted a study addressing an intriguing question.
They wanted to learn whether treatment was likely to be more effective if delivered by a person with whom the recipient of the treatment was already familiar or whether the impact would be stronger if it came from a complete stranger.
"[In the present study,] participants received pain on the back of their hand," explains lead author Grit Hein.
"In one group of participants, this pain was relieved by a person from their own social group, another group of participants received pain relief from a person from a different group. We measured how the pain relief treatment changed neural pain responses and subjective pain judgments," he adds.
The researchers report their findings in the current issue of the journal Royal Society of London B: Biological Sciences.
Care from a stranger is more soothing
First, the researchers recorded the response to pain that all the participants showed before the experiment. "Before the treatment, both groups showed similarly strong responses to pain," says Hein.
Although pain tolerance was about the same for all the participants, the investigator noticed that, after having received analgesic care, the volunteers' perception of pain appeared to change depending on whom they received the attention from.
Thus, those individuals whose pain was treated by someone they did not know beforehand felt that their pain was more diminished, compared with individuals who had received the treatment from a person in their own group.
"In contrast, after being treated by what they considered a 'stranger,' the participants from this group rated their pain less intense than the other group."
Moreover, this effect was not based purely on subjective impressions. As Hein observes, there was also "a reduction of the pain-related activation in the corresponding brain regions" in the case of participants who were treated by a stranger.
Learning patterns may explain results
Hein and team explain that while these findings may seem surprising on first impression, they are not, in fact, unexpected.
The researchers write that the changes in brain activity patterns they observed appeared in the anterior insular cortex. This brain region is associated with, among others, empathetic pain perception.
A notion from learning theory may help us understand why such changes in pain perception occur in the first place. This is the principle of "prediction error learning," which finds that encountering an element of unfamiliarity or surprise allows us to learn certain experiences more quickly.
Within the parameters of the current study, this means that participants were surprised to receive assistance from an unknown person.
The fact that they had not anticipated this positive outcome may have boosted the effectiveness of the treatment, as the participants' brains were acting to accommodate this unexpected turn of events.
"The participants who received pain relief from an outgroup member had not expected to actually get effective help from this person," notes the lead investigator.
Also, the more surprised a participant was to receive attention from a stranger, the greater their surprise was at the fact that the help they received was actually effective, which may have boosted its impact, the researchers speculate.
"Of course, this finding still needs to be verified outside the laboratory, but it could be relevant for the clinical context where treatment by nurses and doctors from different cultures is common today," Hein suggests.