Abstract
The purpose of the current study was to determine whether the perception of object ownership and the presence of a co-actor exert an independent or interactive influence upon the perception of an individual's peri-personal space. Participants completed a stimulus-response compatibility task either in the presence or absence of a confederate. Participants stood in front of a horizontally positioned computer monitor and were required to indicate whether a stimulus (i.e., a picture of either a self-owned or un-owned mug) was upright or inverted. The factors of social context, ownership, and space were manipulated. The analysis of response times revealed a significant interaction between social context and space: social context did not affect RTs for objects in 'far', but for objects in 'near' space, participants responded more efficiently to the mugs located at the near location in the presence of a co-actor than when acting alone. These findings indicate that the perception of peri-personal space became more salient in the presence of a co-actor. Additionally, an ownership by space interaction indicated that RTs for the self-owned object were shorter than for the un-owned object when the object was located at the 'near' location - a facilitation effect for a self-owned object was only observed when the stimuli were located in peri-personal space. The absence of any interaction between social context and ownership, however, indicates that these social cues did not exert an interactive influence upon the coding of space.
