Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale
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The two-point discrimination threshold (2PDT) has been used to investigate the integration of sensory information, especially in relation to spatial acuity. The 2PDT has been investigated for both innocuous mechanical stimuli and noxious thermal stimuli; however, previous studies used different stimulation modalities to compare innocuous and noxious stimuli. This study investigated the 2PDT in 19 healthy participants, using both thermal (laser) and mechanical stimulation modalities. ⋯ The average NRS for thermal stimuli was 1.6 for innocuous intensities and 4.0 for noxious intensities, while for mechanical stimuli, the average NRS was 0.9 for innocuous intensities and 3.6 for noxious intensities. This study showed that the 2PDT highly depends on both stimulation modality and intensity. Within each modality, noxious intensities modulates the 2PDT differently, i.e., noxious intensities lowers the 2PDT for thermal stimuli, but increases the 2PDT for mechanical stimuli.