Comparing intensities and modalities within the sensory attenuation paradigm: Preliminary evidence.

It is well-documented that the intensity of a self-generated somatosensory stimulus is perceived to be attenuated in respect to an identical stimulus generated by others. At present, it is not clear whether such a phenomenon, known as somatosensory attenuation, is based not only on feedforward motor signals but also on re-afferences towards the body. To answer this question, in the present pilot investigation on twelve healthy subjects, three types of stimulations (sensory non-nociceptive electrical - ES, nociceptive electrical - NES, and vibrotactile - VTS) and intensities (1 = sensory threshold ∗ 2.