The influence of body-ownership cues on tactile sensitivity.

To some extent the bodies of others and one's own body are represented differently in the human brain. This study investigates how these different body representations are used during tactile perception. Two types of cues--purely visual cues (pictures of hands) and multisensory cues (equivalent to the rubber hand illusion paradigm)--were used to control whether a seen hand was one's own hand or somebody else's hand. We found that viewing one's own hand improves nonspatial tactile discrimination of supra-threshold stimuli, but attenuates tactile detection performance. Furthermore, when multisensory information signals that the viewed hand is not one's own hand, tactile nonspatial performance seems to be generally sensitized as compared to not viewing a hand. Such body-ownership-specific modulations were present only when multisensory cues signaled body ownership.