Tactile stimulation of the face and hand studied by functional MRI

Background: Tactile stimuli are physiological somatosensory stimuli which predominantly activate touch-encoding afferents. In contrast to electrical stimuli, they can be applied to the face during fMRI. As somatosensory perception depends on experimental factors such as the subject's attention, we compared two different experimental designs for tactile stimulation during fMRI. Methods: Eight right-handed volunteers (four females, four males) were studied with a Siemens Symphony 1.5T scanner during two runs of a blocked and two runs of an event-related design (165 images/run). The intensity of tactile stimuli was…