Interactions between spatial summation, 2-point discrimination and habituation of heat pain

摘要: Recently, spatial summation (SS) of two discrete noxious stimuli was found to occur at separation distances less than 10cm in the forearm. Interestingly though, with larger there is 2-point discrimination (2PD) but not SS. However, previous studies have examined interactions between these phenomena and temporal aspects pain. Therefore, our aims were (1) examine inverse relationship SS 2PD leg, (2) assess whether pain are affected by repetitive stimulation. Twenty-four subjects received multiple series 16 repeated heat (22s inter-stimulus interval) various intensities delivered one or thermal probes separated either 0.4cm 15cm. For each configuration, rated amount perceived on a Visual Analogue Scale (VAS) (to evaluate SS) stated number spots 2PD) following stimulus. A significant occurred only probe (in which significantly increased compared single probe, p<0.001) whereas 15cm (p<0.001). When stimulation temperature fixed (but evoked different initial scores for configurations), habituation when score stimulus varied) all configurations 0.4cm. Sex factor pain, however greater females males. In conclusion, counteracts lesser extent, habituation.