Evidence for pain attenuation by the motor system-based judgment of agency.

Pain is an integral part of our lives. Although the effect of 'control' on sensed pain has been extensively studied and discussed, recent findings seem to be at odds with the substantial evidence for a robust motor-based sensory attenuation effect - an indirect marker for one's sense of agency. The goal of the current study was to re-examine whether there is evidence for such an effect in the context of pain. In three experiments, human participants were aversively stimulated and the sensitivity of self-reported pain to factors previously shown to modulate the sensory attenuation effect was tested (control over parameters of the stimulation; temporal contiguity and predictability, and stimulation intensity). Two of three experiments found some evidence that objective control attenuates pain, but only when the painful stimulation immediately follows the motor response. We discuss the complex relations between having objective control, feeling helpless, predictability and sensed pain.

I control therefore I do: judgments of agency influence action selection.

Our sense of being agents, that is of willingly controlling both our own bodies and the external environment is ubiquitous if thin. Empirical and theoretical work on this 'sense of agency' has documented motivational, cognitive and neural influences on implicit (out of awareness) and explicit (conscious) judgments of agency. For example, fluency of action selection processes has been recently shown to affect judgments of one's degree of control over an external event. However, it is an open question whether and how such judgments of agency act as input to other processes. In this study we demonstrate that the opposite relationship between action selection and judgment of agency also exists. Specifically, we show that manipulating one's objective control over the environment influences both the speed and the frequency of performing an action associated with that control. This pattern bears a striking resemblance to the effect that tangible rewards have on action selection and suggests that positive control feedback is rewarding to the organism, consequently affecting action selection. If further corroborated this 'reward from control' may explain everyday addictions such as prolonged engagement in arcade games and pathological behaviors, such as stereotypy.