The (not so) social Simon effect: a referential coding account.

The joint go-nogo Simon effect (social Simon effect, or joint cSE) has been considered as an index of automatic action/task co-representation. Recent findings, however, challenge extreme versions of this social co-representation account by suggesting that the (joint) cSE results from any sufficiently salient event that provides a reference for spatially coding one's own action. By manipulating the salient nature of reference-providing events in an auditory go-nogo Simon task, the present study indeed demonstrates that spatial reference events do not necessarily require social (Experiment 1) or movement features (Experiment 2) to induce action coding. As long as events attract attention in a bottom-up fashion (e.g., auditory rhythmic features; Experiment 3 and 4), events in an auditory go-nogo Simon task seem to be co-represented irrespective of the agent or object producing these events. This suggests that the cSE does not necessarily imply the co-representation of tasks. The theory of event coding provides a comprehensive account of the available evidence on the cSE: the presence of another salient event requires distinguishing the cognitive representation of one's own action from the representation of other events, which can be achieved by referential coding-the spatial coding of one's action relative to the other events.