Short Communication Prime and probability: Causal knowledge affects inferential and predictive effects on self-agency experiences Anouk van der Weiden a,⇑ , Henk Aarts a , Kirsten I. Ruys a,b a Department of Psychology, Utrecht University, PO Box 80140, 3508 TC, Utrecht, The Netherlands b Social Psychology Department, Tilburg University, PO Box 90153, 5000 LE, Tilburg, The Netherlands article info Article history: Received 7 April 2011 Available online 2 October 2011 Keywords: Self-agency Inference Prediction Outcome priming Outcome probability Causal knowledge abstract Experiences of having caused a certain outcome may arise from motor predictions based on action–outcome probabilities and causal inferences based on pre-activated outcome repre- sentations. However, when and how both indicators combine to affect such self-agency experiences is still unclear. Based on previous research on prediction and inference effects on self-agency, we propose that their (combined) contribution crucially depends on whether people have knowledge about the causal relation between actions and outcomes that is relevant to subsequent self-agency experiences. Therefore, we manipulated causal knowledge that was either relevant or irrelevant by varying the probability of co-occur- rence (50% or 80%) of specific actions and outcomes. Afterwards, we measured self-agency experiences in an action–outcome task where outcomes were primed or not. Results showed that motor prediction only affected self-agency when relevant actions and out- comes were learned to be causally related. Interestingly, however, inference effects also occurred when no relevant causal knowledge was acquired. Ó 2011 Elsevier Inc. All rights reserved. 1. Introduction In most humans, the performance of behavior is often accompanied by a sense of self-agency, that is, the experience of causing one’s own actions and resulting outcomes. These experiences arise under conditions in which the cause of outcomes is clear, such as when one knows that one’s own action leads to the outcome, but also when self-causation is more ambig- uous, such as when the outcome may occur independently of one’s own action. Accordingly, the literature distinguishes two main processes that contribute to experiences of self-agency (e.g., Moore & Haggard, 2008; Moore, Lagnado, Deal, & Haggard, 2009). First, experiences of self-agency depend on the extent to which our motor control system is able to predict the sensory outcome that is produced by performing a specific action. Second, self-agency can be cognitively inferred, based on whether the outcome corresponds with the outcome we had in mind. So far, however, research has not clearly addressed when and how motor predictions and cognitive inferences combine to affect experiences of self-agency. Based on previous research on the effects of prediction and inference on self-agency (Sato, 2009), we propose that the influence of motor predictions and cognitive inferences on experiences of self-agency crucially depends on knowledge people have about the causal relation between actions and outcomes. Such causal knowledge refers to the information that a person has to assess the consequences of a specific action. Basically, this knowledge is obtained when the motor control system learns that the execution of a specific motor command leads to a specific sensory outcome. One can learn such a relation through direct performance of an action and subsequent observation of the outcome, but also 1053-8100/$ - see front matter Ó 2011 Elsevier Inc. All rights reserved. doi:10.1016/j.concog.2011.09.007 ⇑ Corresponding author. Fax: +31 30 253 4718. E-mail address: a.vanderweiden@uu.nl (A. van der Weiden). Consciousness and Cognition 20 (2011) 1865–1871 Contents lists available at SciVerse ScienceDirect Consciousness and Cognition journal homepage: www.elsevier.com/locate/concog