Attentional orienting to own and others' hands

High-density electroencephalographic recordings were used to investigate the level of analysis at which attentional expectations modulate the processing of specific stimuli from the same perceptual category but differentiated in terms of a particular non-perceptual feature: body ownership. We used a task in which colour cues predicted whether a picture of a hand stimulus belonged to the participant or to somebody else. Participants were instructed to respond whether the target was a left or a right hand. Results revealed that the ERP pattern depended on stimulus ownership and attention orienting, which influenced the visual processing of own and someone else's hands differentially. Larger amplitude for others' than for own hands was shown at the N1 deflection (at the right hemisphere). Attentional effects were found at the P2 and P3 potentials. The P2 reflected an interaction between stimulus ownership and attentional orienting, due to a larger validity effect for others' hands. At the P3 level, the data showed a significant validity effect only for self-hand stimuli. In sum, our results suggest that (1) differences as a function of stimulus ownership can be detected at early levels of stimulus processing; (2) endogenous attention can be directed to exemplars within the same category, hand stimuli in this case; (3) the effects of attention are modulated by ownership.