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An action that produced an effect is perceived later in time compared to an action that did not produce an effect. Likewise, the effect of an action is perceived earlier in time compared to a stimulus that was not produced by an action. Despite numerous studies on this phenomenon-referred to as Intentional Binding effect (IB)-the underlying mechanisms are still not fully understood. Typically, IB is investigated in settings where the action produces just one single effect, whereas in everyday action contexts, it rather causes a sequence of effects before leading to the desired outcome. Therefore, we investigated IB of two consecutive effects. We observed substantially more IB of a first effect tone compared to a second tone. This pattern was observed for second tones that were temporally predictable (Exp. 1) or not (Exp. 2 and 3). Interestingly, the second tone yielded stronger IB when it was less delayed (Exp. 4). Thus, also an event occurring later in an unfolding action-effect sequence can be bound to its causing action, but it might be less bound to the action than a first effect. Instead of the fact that it is the second of two consecutive effects, this, however, rather seems to be influenced by the longer delay of a second and, therefore, later occurring effect.

In the current study, we investigate whether sense of agency over an effect coincides with the perceived time of the effect that occurs either at its usual time or earlier or later than usual. One group of participants usually perceived an action effect immediately after the action, another group delayed by 250 ms. In test blocks the effect stimulus was sometimes presented earlier or later than usual. Participants judged either the degree of experienced agency over the effect or whether the effect had appeared at its usual time, or earlier or later than usual. In both groups experienced agency and the perception of the effect's time 'as usual' were highly correlated. To rule out that time judgments influenced sense of agency, we replicated the pattern of agency judgments in Experiment 2 in which participants only judged agency. Taken together, we demonstrated that agency and time judgments vary similarly across temporal deviations of effects irrespective of to which delay participants were adapted to. The high correlation of judgment types indicates that perceiving an effect at its usual time and sensing to have caused the effect are closely related. In contrast, physical temporal proximity of actions and effects has only a minor impact on experienced agency.

When an action produces an effect, both events are perceived to be shifted in time toward each other. This shift is called Intentional Binding (IB) effect. First evidence shows that this shift does not depend on the statistical predictability of the produced effect's identity (Desantis, Hughes, & Waszak, 2012). We confirm this result by comparing the perceived duration of action-effect intervals before valid and invalid action effects using the method of constant stimuli. The perceived duration of action-effect intervals did not differ for valid and invalid effects. This result was true for different durations of the action-effect interval (Experiments 1-4: 250 ms, Experiments 1 & 2: 400 ms), different effect modalities (Experiments 1 & 3: visual, Experiments 2-4: auditive), and two types of validity variations (Experiments 1 & 2: 80% valid, Experiments 3 & 4: 100% valid vs. random). We validated our results by using a clock paradigm and a numerical duration estimation task (Experiment 4). We conclude that the IB effect is not the result of internal prediction due to action-effect bindings, but might rely on higher-order processes., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Intentional binding describes the phenomenon that actions and their effects are perceived to be temporally approximated. We introduced a new method of duration estimation to the research field, the method of constant stimuli. Participants freely chose to press one of two keys or experienced passive key presses. After an interval of 250 ms or 600 ms a visual effect occurred. In Experiment 1, each key produced an effect after a specific interval. In Experiment 2, both keys produced an effect after the same interval that varied between sessions. Participants compared the duration of the action-effect interval with a tone of varying duration. To assess intentional binding, we compared the perceived duration of the action-effect interval between the active and passive condition. We showed intentional binding for 600 ms, but not for 250 ms action-effect intervals in both experiments. Thus, the method of constant stimuli is suitable to assess intentional binding., (Copyright © 2012 Elsevier Inc. All rights reserved.)