Everyone can relate to pain and research has shown that the face is considered a finely tuned medium for pain communication. Studies assessing the decoding of pain facial expressions, however, have revealed an interesting discrepancy according to a study published online January 2 in the Journal of Pain. Despite narrowing of the eyes being the most frequent facial expression accompanying pain, individuals mostly relied on brow lowering or nose wrinkling/upper-lip curling as a better way to evaluate pain based on facial appearance.
The study examined if this discrepancy may reflect an interaction between the features coding pain expressions and the features used by observers and stored in their mental representations.
The first experiment showed that more weight is allocated to individuals lowering their brow and wrinkling their nose and curling their upper lip to support the idea that these features are allocated more importance when mental representations of pain expressions are stored in memory. The second experiment showed that these features remained more striking than narrowing of the eyes even when attention is specifically directed towards the sensory dimension of pain, the study found.