A new study from Aarhus University has uncovered that uncertainty, not just expectation, significantly influences pain perception. This discovery could reshape pain management strategies, helping alleviate unnecessary pain by providing patients with clearer information.
A new study by researchers at Aarhus University, published in the journal Science Advances, has revealed that uncertainty plays a crucial role in how we perceive pain, potentially making it worse. This finding challenges the existing belief that expectation alone shapes pain experience and could have significant implications for pain management.
“Our results show that uncertainty, not just expectation, plays an important role in pain,” corresponding author Francesca Fardo, an associate professor at Aarhus University, said in a news release.
The study, conducted by the Department of Clinical Medicine at Aarhus University, designed an experiment where participants were asked to predict whether they would feel a warm or cold sensation on their forearms. Sometimes, the participants were subjected to both warm and cold stimuli simultaneously, triggering a phenomenon known as the thermal grill illusion, which leads to a sensation of burning pain.
“Previous research has shown that our expectations shape how we experience pain. In this study, we wanted to find out whether uncertainty in those expectations, or when the brain doesn’t have a clear prediction, could also increase the pain,” added Fardo. “By taking advantage of the curious case of the thermal grill illusion, we could show that even when nothing harmful is happening, not knowing what to expect somehow makes us feel a fairly high level of pain.”
The experiment combined sophisticated brain imaging with computer modeling in 300 participants, allowing researchers to observe how uncertainty responses are linked to specific parts of the brain. The results suggest that when the brain encounters ambiguous signals, it errs on the side of caution, increasing perceived pain.
“Previous research on placebo and nocebo effects has shown that expecting relief can reduce pain, while expecting harm can make pain worse. Our findings add a new layer: when the brain is unsure about what to expect and encounters ambiguous signals, it errs on the side of caution, intensifying pain beyond what’s necessary,” Fardo added.
These insights might significantly influence how pain is managed and treated, particularly for patients facing anxiety and uncertainty regarding medical procedures.
“In the short term, these findings might help pain scientists better understand how these processes work, and they may also help to guide health professionals in better tailoring pain management strategies, such as by giving clearer information or setting precise expectations, so patients feel less uncertain about what’s coming,” added Fardo.
Looking ahead, Fardo aims to replicate the study in individuals with chronic pain and explore the potential impact of psychological factors, such as depression and anxiety, on pain perception.
Source: Aarhus University