A new study carried out by scientists in the US suggests that people experience pain differently due to individual differences in brain structure.
For their study, the researchers from Wake Forest Baptist Medical Centre in Winston-Salem, North Carolina recruited 116 healthy volunteers and tested their sensitivity to pain by asking them to rate pain intensity whilst a small area of skin on their arm or leg was heated to 120 degrees Fahrenheit. After the pain sensitivity test the participants were given MRI scans to record images of their brain structures. The perceived pain intensity was then compared with the differences in brain structure.
The brain contains grey matter, which processes information, and white matter, which coordinates communication among the various brain regions. The results showed that participants with the highest pain intensity ratings had less grey matter in brain regions known to be involved in internal thoughts and attention control. This included two regions that are part of the default mode network. The default mode network is a group of interlinked brain regions that are associated with the free-flowing thoughts people experience as "day-dreams."
Professor Robert Coghill who led the study says: "We found that individual differences in the amount of grey matter in certain regions of the brain are related to how sensitive different people are to pain."
He suggests that the findings may help develop better ways of diagnosing, classifying, treating and perhaps even preventing pain.
The study was reported in the online issue of the journal Pain.
