To answer this question, Milica Nikolic and Desa Suter from the University of Amsterdam teamed up with Simone de Plinio from the University of Chieti, under the supervision of Christian Keyers and Valeria Gazzola from the Netherlands Brain Institute.
“Blushing is an interesting phenomenon because we still don’t know what cognitive skills are required for it,” explains developmental psychologist Nikolic. “There’s an idea in psychology that goes back to Darwin, who said that blushing happens when we think about something other people think about, which involves relatively sophisticated cognitive skills.
Redness in karaoke preparation
The researchers examined blushing by looking at which brain regions were active in an MRI scanner while the temperature of the cheeks was recorded—an indicator of facial blushing. The participants were teenage girls, a group that is generally concerned about what others think of them. “Blushing is known to increase during this stage of life, as teenagers are very sensitive to the opinions of others, and may fear rejection or not want to make the wrong impression,” Nikolich explains.
To elicit a blushing response in a controlled experimental setting, participants came to the lab for two separate sessions. During the first session, they were asked to sing deliberately difficult karaoke songs, and in the second session they watched recordings of themselves while their brain activity and physiological responses were measured.
To make matters more difficult, they were also told that an audience would be watching their recording. Finally, the participants were shown recordings of another participant who sang at a similar level, and a professional singer who pretended to be a third participant.
The mechanism behind facial blushing
As expected, the researchers found that participants blushed more while watching their own recordings than when watching other participants’ recordings.
The corresponding brain regions were somewhat surprising. Blushing was associated with increased activity in the cerebellum, an area known to be involved in movement and coordination. “Recently, there’s been a lot of research suggesting that the cerebellum is involved in emotional processing,” Nikolich says. The researchers also found increased activity in visual areas, suggesting that the videos of their singing had captured participants’ attention.
Surprisingly, there was no activation in areas typically involved in understanding one’s own or others’ mental states. “Based on this, we concluded that thinking about other people’s thoughts is not necessary for blushing,” Nikolich concludes. “Blushing may be part of the automatic arousal that occurs when you’re exposed to these types of situations.”
