When we accidentally touch something familiar, like a hot pan, our brain already knows what to expect and how painful it will be. But if you're blindfolded and unaware of touching a hot pan, the pain would feel much more intense—even if the pan isn't hot enough to cause damage.
Pain is perceived as more intense when it's unexpected, according to new research by Danish scientists.
Neuroscientists at Aarhus University in Denmark exposed participants to varying temperatures on their skin—sometimes cold, sometimes warm, and sometimes both simultaneously. This created a harmless but painful effect known as the 'thermal grill illusion.'
Participants had to predict whether they would feel cold or heat beforehand. Uncertainty about what they would experience made them perceive the pain as more severe.
"Previous studies show that our expectations shape how we experience pain," says Associate Professor Francesca Fardo. "Even when nothing serious is happening, not knowing what to expect can make pain feel stronger."
According to Fardo, the brain reacts to uncertainty by "erring on the side of caution" and amplifying the pain response more than necessary. These insights could help treat patients with pain-related anxiety.
"These findings can help pain researchers better understand these processes," Fardo explains. "Healthcare providers can also develop targeted strategies to manage pain better, such as giving patients clearer information and managing their expectations."
Fardo aims to expand the research to chronic pain and the role of anxiety and depression, which could lead to better treatments for long-term pain sufferers.