Intentional Binding for Unintended Effects

We execute most of our movements in order to elicit an intended effect. This kind of intentionality is commonly assumed to drive a temporal illusion, referred to as Intentional Binding (IB): Stimuli intentionally elicited by one's own action (i.e., effects) are perceived as temporally earlier compared to unintentionally occurring stimuli (not elicited by one's own action). It is currently under debate whether intentionality is necessary for IB to occur, or whether causality might be sufficient for IB to occur. In the present study, we investigated the importance of an intention for the occurrence of IB. Employing a Libet Clock paradigm, we assessed IB for effects which participants were instructed to cause by their action (i.e., intended effect) as well as for effects participants were instructed not to cause by their action (i.e., unintended effect). Both effects, the intended as well as the unintended, were subject to IB, with a Bayesian analysis favoring no difference for both effect types. This implies that even an unintended effect is subject to IB and that, thus, causality instead of intentionality might be sufficient for IB.