Intentional Binding in Automated Control Settings Figure 5. Modulation of interval estimates and explicit judgement of agency by automation level. doi:10.1371/journal.pone.0034075.g005 binding may be a useful measure in future cognitive engineering studies. Binding by degrees Our results reveal a gradual increase of interval estimates with the increasing level of automation. In contrast, many previous studies of agency have relied on binary agency-attribution judgements [21]. In binary agency-attribution, judgements of agency may depend on a match between predicted and actual effects, leading to a simple ‘me’ vs. ‘not me’ decision [22]. Our finding of binding by degrees goes beyond a simple compare and decide model. Instead, our results suggest that several features of the way in which intentions guide and sustain action contribute to the experience of acting, and the sense of control. In particular, in our task participants always judged the interval between command engagement and conflict resolution. However, we found that the amount of operator involvement in processing stages preceding the command engagement, such as decision and implementation of the heading adjustment, strongly influenced interval estimates. Thus, specific subprocesses of intentional control may be relevant for sense of agency. For example, processes that generate and select between action alternatives may also contribute to the sense of control over action outcomes (see also [23]). In contrast, previous work emphasised the role of retrospective comparison of intended and actual outcomes in agency judgements [24], [25]. More generally, our result suggests action selection, planning and intention realisation may all contribute to sense of agency. In this way, our results are consistent with recent arguments that sense of agency is based on cue integration [26]. Binding effect and time constraints Our results suggest that temporal binding is not present for the shortest interval tested here (750 ms). Other studies have suggested that longer action–outcome intervals were associated with reduced binding [7], [9], [27]. Here we show that very short intervals could also decrease the intentional binding effect. Interestingly, the short interval tested here corresponds to a large interval in previous studies [9], suggesting this is unlikely to be simply a floor effect. The complex nature of the actions and their effects in our device may explain the preferential binding over longer intervals. We propose that temporal contiguity is task dependent and that intentional binding occurs in a specific ‘‘window of opportunity’’ which may vary across tasks, and may also depend on the range of action-effect delays experienced in a given setting. Operant learning is similarly sensitive to the natural time delays of the system linking actions to effects, even for systems as familiar as one’s own body. For example, when rats learn to avoid eating food associated with illness, the optimal delay between eating and illness is not the shortest possible delay, but a delay consistent with their normal digestive operation [28]. Conclusion We found a distortion of time perception in the control of complex machinery, which adds to a growing literature on sense of agency. Our findings are significant in four ways: First, demonstration of binding effects in a richer and more complex paradigm provides external validity for intentional binding. Second, we show agreement between implicit binding measures of sense of agency, and explicit agency judgement, in such a complex setting. Third, we demonstrate that intentional binding PLoS ONE | www.plosone.org 5 March 2012 | Volume 7 | Issue 3 | e34075