The two-point discrimination threshold depends both on the stimulation noxiousness and modality

The two-point discrimination threshold (2PDT) has been used to investigate the integration of sensory information, especially in relation spatial acuity. 2PDT investigated for both innocuous mechanical stimuli and noxious thermal stimuli; however, previous studies different stimulation modalities compare stimuli. This study 19 healthy participants, using (laser) modalities. Within each modality, intensities were applied. Concurrent point applied right volar forearm, with separation distances 0–120 mm, steps 10 mm. 0 mm corresponds a single point. Following stimulus, participants indicated number perceived points (1 or 2) intensity (NRS: 0: no perception, 3: pain threshold, 10: maximum pain). order distance was randomized. 34.7 47.1 respectively. For stimuli, 80.5 66.9 average NRS 1.6 4.0 intensities, while 0.9 3.6 intensities. showed that highly depends on modality intensity. modulates differently, i.e., lowers but increases