Pain is a multidimensional perception that is complex in nature. It is a unitary construct that includes overlapping domains such as intensity, affect, quality, and frequency. These domains do not reflect the amount of tissue damage. It reflects the end result of the perception of pain in which multiple biopsychosocial factors are involved (Gatchel et al., 2007). Multiple self-reported measures have been used in an attempt to capture most factors that may influence pain such as psychological factors. However, there is no one scale that can be used to characterize pain as a whole with all its factors. Furthermore, physical measurements did not prove to be better than self-reported measure in pain characterization. Since pain perception is believed to occur in the brain, it seems rational to measure aspects of the brain as a biomarker for pain. One method that has been recently used is functional connectivity magnetic resonance imaging (fcMRI), which is a measure of the connectivity between brain regions that are previously known to be related to pain.
In this paper the focus will be on the recent “physical measure” of pain in comparison to the self-reported measure, the Gracely box scale. First a summary of the reliability and validity of the Gracely box scale will be mentioned. Then the development of the functional connectivity based on the fMRI studies will be addressed. Finally, I will assess the reliability and validity of the measure compared to the Gracely box scale.