Every Brain Has Unique ‘Pain Fingerprint’

By Pat Anson, PNN Editor

They say no two fingerprints or snowflakes are alike. The same may also be true about pain perception.

UK researchers say brain waves -- called gamma oscillations – vary so much from person to person they could be called “pain fingerprints.” That may explain why there is such wide variability in how we feel pain and respond to it.

Scientists at the University of Essex subjected 70 people to brief touch and pain stimulation with a laser, while their gamma oscillations were monitored with an electroencephalogram (EEG), a test that measures electrical activity in the brain using small electrodes attached to the scalp.

The study findings, published in the Journal of Neurophysiology, showed that every participant’s gamma waves had distinct patterns when stimulated, with major differences in the timing, frequency and location of the gamma oscillations. Some had no gamma response when subjected to pain, while others had a large response. 

“Not only, for the first time, can we pinpoint the extreme variability in the gamma response across individuals, but we also show that the individual response pattern is stable across time,” said lead author Elia Valentini, PhD, a Senior Lecturer in the Department of Psychology and Centre for Brain Science, University of Essex. 

“This pattern of group variability and individual stability may apply to other brain responses, and characterizing it may allow us to identify individual pain fingerprints in the activity of the brain.” 

JOURNAL OF NEUROPHYSIOLOGY

Previous studies of how pain changes gamma waves focused on group data, while overlooking individual differences. As a result, some scan results were discarded as background noise, leading to false conclusions.  

The new study found that every participant’s gamma waves were highly individual and “remarkably stable.” It’s not clear why there is such variation between individuals, but Valentini hopes his study will change the way gamma oscillations are measured in future research. 

“I think we need to go back to square one because past findings on the relationship between pain and gamma oscillations do not represent all the participants,” he said. “Our results indicate that current EEG measures do not reflect the complex reality of the diverse individual response patterns to brief pain and touch experiences.”

New research could lead to a better understanding of how we perceive and manage pain. Instead of one-size-fits-all therapies, future treatments could be tailored to our individual “pain fingerprints.”