Self-agency

Fritz Heider and Mary-Ann Simmel (1944) conducted seminal work on the perception of external causal events. Work on attribution of agency to oneself, however, began with Benjamin Libet's demonstration that brain activity predictive of action precedes conscious awareness of the intention to act (Libet, Gleason, Wright and Pearl 1983; Libet 1985). Since this demonstration psychologists have been trying to determine the relationship between the sense of agency, also known as the phenomenal will, and actual self-agency.

Daniel Wegner’s book The Illusion of Conscious Will (Illusion of control; 2002; see also Wegner 2003 and 2004) posits the phenomenal will as the illusory product of post hoc inference. Sense of agency, on this view, is a product of fallible post hoc inference rather than infallible direct access to one's conscious force of will. The attribution of self-agency is made most strongly when the following three conditions are met: priority, exclusivity, and consistency. Thus, one's action must be the exclusive potential cause of the event (exclusivity), one must have had prior thoughts or plans about the action before it occurred (priority), and the action the occurred must match the action that was planned (consistency). An inference of self-agency is thus made under at least three parameters of uncertainty.

Most studies of self-attribution of agency can be categorized as examining one or more of Wegner's three conditions of priority, exclusivity, and consistency. By manipulating these three parameters in systematic ways, researchers have shed light on the role that each plays in self-attributions of agency.

Wegner's account is a leading example of a postdictive or inferential account of the attribution of self-agency. On this type of view, the feeling of self-agency emerges entirely from post hoc inference and does not track or emerge from anything directly related to the actual causation of the action.

Computational models of motor control, by contrast, hypothesize that the sense of agency for a given action arises most directly from internal motor representations associated with generating the movement. An internal forward model based on efference copy, for example, can predict the sensory consequences of a motor command and compare them with the actual sensory state after that action has been initiated (Blakemore, Wolpert and Frith, 2000, 2002; Haggard, 2005). If the actual sensory state matches the predicted one, self-agency is (likely to be) inferred. Indeed, the intentional binding effect (described above) may depend on the motor efference command; Engbert, Wohlschläger and Haggard (2008) provide data suggesting that compression of estimated intervals between action and effect occurs only for volitional actions initiated by the self and not for passive actions or for actions performed by others. These authors maintain an efferent motor command is necessary for a sense of agency. Indeed, omitting the effect of an action does eliminate intentional binding, so long as the probability of an effect given an action is sufficiently high (Moore and Haggard, 2008).

Synofzik, Vosgerau and Newen (2008) review findings on comparator models and argue that they cannot account for either a feeling of agency or a judgment of agency. Their multifactorial model separates feeling from judgment and discusses the conceptual level of processing that is added to the latter. Their discussion concerns explicit judgments of agency, however, which may differ from results obtained using implicit measures (e.g., Engbert, Wohlschläger and Haggard 2008).

Moore, Lagnado, Deal and Haggard (2009) investigated whether statistical contingency alone could explain both predictive and inferential ‘‘postdictive” intentional binding effects. Both predictive and ‘postdictive' shifts in the time of action perception depended on strong contingency between the action and effect, suggesting that the experience of agency involves causal learning based on statistical contingency.

Although predictive and postdictive accounts of agency are often cast as competitors, they may in fact be reconcilable when attributions of self-agency are viewed within the framework of cognition under uncertainty. In particular, a comparator model based on efference copy can be seen as a more sophisticated way of characterizing Wegner's consistency parameter and the computations that are likely to be a part of it. Basing outcome predictions on motor commands, rather than just higher-level representations of the goal state that an action is intended to bring about, is likely to provide finer-grained predictions with which to compare outcomes, thereby reducing uncertainty in agency attributions. This higher predictive resolution, in turn, could be useful in making exclusivity judgments (Wegner's second condition): even if a particular goal state is brought about, if the way it is brought about does not closely match the motoric prediction, the attribution of agency may be reduced or blocked entirely. Similarly, given evidence (discussed above – see Haggard, Clark and Kalogeras 2002) that whether or not an action is volitional affects intentional binding, motoric representations and predictions seem also to affect Wegner's priority parameter. As such, predictive and postdictive accounts may simply differ in emphasis and in the level at which they describe the phenomenon, rather than being fundamentally incompatible.

• Free will
• Neuroscience of free will
• Self-efficacy
• Volition (psychology)