Acting and reacting: Is intentional binding due to sense of agency or to temporal expectancy?

Intentional Binding (IB) refers to the phenomenon that we perceive effects we caused by a voluntary action earlier compared to stimuli we did not cause by our action. Although IB has been investigated in numerous studies and is routinely employed as an implicit measure for Sense of Agency, its underlying mechanisms are not yet clear. We investigated whether IB is based on Sense of Agency or on temporal expectancy. To this end, we compared how delay duration (250 ms vs. 600 ms) and duration predictability (valid vs. invalid) influence IB regarding Sense of Agency, measured as agency judgment (AJ), and temporal expectancy, measured as reaction time benefit (RTB). Results pattern were quite similar for IB and AJ but different for IB and RTB: IB and AJ decreased for longer delay durations, whereas the RTB increased for longer delay durations. An additional interaction of delay duration and duration predictability was only significant for AJ and RTB. Yet, the interactional pattern of delay duration and duration predictability on AJ did not differ from the result pattern of IB. Overall, results indicate IB to be rather driven by Sense of Agency than by temporal expectancy. (PsycINFO Database Record (c) 2019 APA, all rights reserved).