Spatial acuity, or the ability to identify where it hurts, is different at different parts of the body, a new study reveals.
The researchers produced the first systematic map of how acuity for pain is distributed across the body and found that forehead and fingertips are the most sensitive parts.
Dr Flavia Mancini of the UCL Institute of Cognitive Neuroscience said that acuity for touch has been known for more than a century and tested daily in neurology to assess the state of sensory nerves on the body but it is striking that until now nobody had done the same for pain.
Senior author Dr Giandomenico Iannetti of the UCL Department of Neuroscience said that touch and pain are mediated by different sensory systems and while tactile acuity has been well studied, pain acuity has been largely ignored.
The findings have important implications for the assessment of both acute and chronic pain.
The study is published in the journal Annals of Neurology.