There are areas in the brain that deal specifically with the expectation of pain, as well as with the painful sensation itself, new research has shown.The finding not only explains why certain mind-based techniques can play a role in the management of chronic pain, but it may also lead to better anti-pain drugs.
In the research, published in today's Science, scientists from Oxford University used magnetic resonance imaging to monitor the brain activity of a group of people as they felt a series of painful sensations on their hands, each signaled in advance by a coloured light.
This allowed them to show something no research team had demonstrated before - there are two distinct phases in the perception of pain.While certain brain areas "lit up" when the painful sensation itself was experienced, this was preceded by stimulation in separate but nearby areas when the "pain warning" light was switched on.
Stimulation of the brain's "pain anticipation" regions is known to trigger feelings of fear or anxiety as well as other mood changes, said the team's head researcher Dr Alexander Ploghaus. And unfortunately the anxious feelings can make the painful sensations that follow feel worse.
But the new research might help in the screening of anti-pain medications for such people. If the anticipation part of the pain response can be removed, it would reduce the overall "pain load".