GRIFFITHS AND TIPPER At ﬁrst glance, this result may be considered to be similar to the effects when individuals learn to use tools. That is, after experience of interacting with objects with a tool, near (peripersonal) space is extended to include the tool (e.g., Iriki, Tanaka, & Iwamura, 1996). However, critically this tool effect requires direct interactions between the hand, the tool, and the manipulated object, where visuomotor and tactile feedback adjust the represen- tation of space, so that more distant objects are encoded as within action space. The requirement for direct interactions between hand, tool, and object is reﬂected in the nature of learning, where it is speciﬁc to the hand trained to use the tool (e. g., Bassolino, Serino, Ubaldi, & Làdavas, 2010) and does not take place if the tool is merely held (e.g., Làdavas & Farnè, 2006). In sharp contrast, in our study there is no visuomotor/tactile feedback. Participants do not learn to manipulate far space, as they passively view another person’s actions, and objects always remain out of reach. Furthermore, the observation and production of action are identi- cal in the separate- and shared-workspace con- ditions, but only the latter situation produces action simulation. Another interpretation of our results might be in terms of joint actions—that is, when individuals interact together to achieve a joint goal, such as lifting a heavy weight or dancing, by coordinating their actions (e.g., Sebanz, Bekkering, & Knoblich, 2006). However, a joint action account would seem to be unlikely in our experiment. Participants were instructed to perform their own reaching task and were asked to merely passively observe the other person’s actions. Both individuals’ actions are therefore undertaken at different times, not coordinated in any way, and the observed action is not relevant to a participant’s own sub- sequent action. Finally, the current effects might be mediated by memory processes inﬂuenced by ownership. That is, in the separate-workspace condition, observed actions are outside action space, and they are not encoded into memory, hence no priming effects are observed a few seconds later. However, in the shared-workspace condition, participants have greater ownership of the objects and workspace, 1248 and ownership has previously been shown to improve memory (e.g., van den Bos, Cunnigham, Conway, & Turk, 2010). That is, objects that are “owned” by a participant are better encoded into episodic memory and subsequently recalled than those “owned” by another person. Hence, in our study, we propose that the motor states activated when a participant observes another person reach over an obstacle that the participant also interacts with are maintained in memory and inﬂuence a participant’s own reach trajectory a few seconds later. The simulation of another person’s actions as a means of understanding them is an important process. The current work shows that these action simulation processes are not automatic and inﬂex- ible, but can be inﬂuenced by ownership of objects and environments. These ﬁndings are novel because they cannot be accounted for by typical explanations based on tool use or joint actions. Rather we propose that simulation of observed actions can be selectively activated and maintained in memory when of particular relevance, which can be determined by ownership. Original manuscript received 27 February 2012 Accepted revision received 17 April 2012 First published online 8 June 2012 REFERENCES Bassolino, M., Serino, A., Ubaldi, S., & Làdavas, E. (2010). Everyday use of the computer mouse extends peripersonal space representation. Neuropsychologia, 48(3), 803–811. Binkofski, F., Buccino, G., Posse, S., Seitz, R. J., Rizzolatti, G., & Freund, H. J. (1999). A frontopar- ietal circuit for object manipulation in man: Evidence from an fMRI-study. European Journal of Neuroscience, 11(9), 3276–3286. Bowers, D., & Heilman, K. M. (1980). Pseudoneglect: Effects of hemispace on a tactile line bisection task. Neuropsychologia, 18(4–5), 491–498. Costantini, M., Committeri, G., & Galati, G. (2008). Effector- and target-independent representation of observed actions: Evidence from incidental repetition THE QUARTERLY JOURNAL OF EXPERIMENTAL PSYCHOLOGY, 2012, 65 (7)