Cerebral Activation Patterns of Tactile, Phasic and Tonic Painful Stimulation in Humans

Non-painful and painful stimuli are known to activate neighboring regions or even the same areas like the somatosensory cortices. Other activation areas seem to be predominantly, or exclusively, active when a stimulus is painful. In this fMRI study we compared different cerebral activation patterns evoked by three types of stimulation. 12 healthy subjects underwent a balanced series of 1) non painful tactile stimulation with a 128 mN v. Frey hair, 2) phasic painful stimulation with a 128 mN pin prick stimulator, and 3) tonic painful stimulation using a thermode (temperature oscillation around the individual heat…