Sense of agency in continuous action is influenced by outcome feedback in one-back trials.

Sense of agency (SoA) is a subjective feeling that a person controls his/her own actions and causes changes in the external world. In continuous action such as controlling a dot by keypresses, SoA is influenced by actual actions during the task. Additionally, it is known that even though the actual actions were almost identical, outcome feedback (e.g., success or fail) could modulate SoA, indicating a retrospective modulation of SoA. However, it was unclear whether the SoA modulated by outcome feedback would influence SoA for an up-coming action. Here, we investigated the effects of outcome feedback in one-back trial on SoA in the present trial (i.e., prospective modulation). We conducted three experiments where participants controlled a dot to a target whose color changed unpredictably between white and blue. If the dot reached the target when the color was white (blue), participants received a text feedback of "Success" ("Fail"). However, in fact, we predetermined the outcome feedback to remove the effects of the actual performance of participants on SoA. The results showed that if the outcome feedback of the one-back trial was successful, SoA of the present trial became higher (i.e., prospective modulation) until they received the outcome feedback. Moreover, the prospectively modulated SoA was retrospectively overwritten by the outcome feedback of the present trial and likely converged to a constant level. These findings indicated that SoA was not produced by a mere sum of the prospective and retrospective factors, but rather that these factors independently influenced SoA with differential time courses.