Here is another study that shows how our feelings about pain can influence the amount of pain perceived. This is the area where we hypnotist can do so much for our clients in the area of pain management.
Reported in the journal PNAS, Proceedings of the National Academy of Sciences, people that are more anxious, or worried about feeling pain, have differences in connectivity within their brains that make them more susceptible to actually feeling pain.
The team applied short laser pulses to the feet of 16 willing and healthy volunteers just at the point where they started to experience the pulses as being painful ('you can ratchet up the laser pulses so you feel them as warm, then hot, then the point where you say "yeah, actually, that hurts now,"'. These brief laser pulses were applied 120 times to each volunteer, and around half the time the volunteer would declare it was painful and half the time not -- even though the pulse was exactly the same every time.
MRI brain scans during these experiments show that the volunteers' brains were more active in pain-processing regions when they described the laser pulses as being painful -- so this was a real experience and not down to any report bias or artefact.
The researchers at the Oxford Centre for Functional Magnetic Resonance Imaging of the Brain, looked at the period just before the stimulus and wondered if there was a difference in the way certain regions of the brain are connected or communicating before the stimulus was applied.
The researchers focused on the connection between 'higher' parts of the brain involved in the processing of pain, and part of the brain stem that can powerfully alter the experience of pain -- turning its level up or down.
When there was good coupling between the two areas before a laser pulse, the volunteer felt no pain, and when the connectivity was poor, the pulse was experienced as painful.
Most interestingly of all, however, was that people that were more likely to be anxious or vigilant about pain (as scored on their answers to a questionnaire for these traits), showed poorer connectivity in general between these brain regions.