Women have more intense responses to pain than men, say scientists.
Doctors were investigating gender differences in how the sexes respond to the pain of chronic conditions such as Irritable Bowel Syndrome - which affects more women than men.
But the findings also shed light on the age-old debate about the sensitivity of the sexes.
A research team from London and Japan led by Professor Qasim Aziz, of the Wingate Institute for Neurogastroenterology, Queen Mary University of London, studied brain activity and reactions of 16 men and 16 women in the anticipation and processing of pain.
The study involved healthy volunteers who were told that a tiny balloon would be expanded in the gullet, before the procedure lasting a second.
During the period leading up to it, women had less activity in areas that process fear and more activity in areas involved in preparing and planning movements to avoid the impending pain.
In men, fear was predominant when they were expecting to feel pain.
During the painful event the opposite reaction was seen among men who were more involved with pain avoidance.
In contrast, women showed greater activity in areas involved in processing emotions and feeling the pain.
"The fact that during pain our female subjects showed more activation of the emotion processing areas in the brain could suggest a mechanism whereby females may attribute more emotional importance to painful stimuli which may influence how they perceive, report and respond to pain in comparison to males," the Daily Mail quoted Prof Aziz as saying.
"Further research is now required to assess the clinical importance of these findings and to determine if brain imaging studies can help to guide therapy," Prof Aziz added.
Findings from the scans will be released at the British Society of Gastroenterology`s annual meeting in Birmingham.