关键词: 施动感, 动作自主性, 结果性质, 预测性, 时间压缩效应

Abstract:

Sense of agency (SoA) is the feeling of having control over an external event through one’s own actions. SoA is a result of the connection between one's intentions, actions and outcomes. In addition, predictability of outcomes can also have an effect on SoA. Previous studies have found that threats can reduce agency, but these results are mostly limited to aggressive behavior. A pro-social outcome is often attributable to one's own action. However, it is unclear whether a person can change their perception of their actions and results. In this study, we used the Temporal Estimates method to examine the effects of voluntary action and the nature of outcomes on the sense of agency under predictable and unpredictable conditions.

We used the temporal binding paradigm in order to measure the interval time in a card game task. The intensity of the sense of agency was linked with the estimated interval time. Self-interested and altruistic monetary rewards or neutral outcomes were presented to the participants. In both experiments, a neutral tone emerged by pressing buttons on their own initiative (voluntary action) or following instructions (involuntary action), respectively, under predictable conditions (Experiment 1) and unpredictable conditions (Experiment 2). Time interval from the action to the outcome was set to 200 ms, 500 ms, and 800 ms. Each interval was chosen randomly. In the experiments, participants were asked to estimate the time interval between the keys and the sound or picture, which was expressed as a number between 100 and 1000 ms. As the time interval increased, the sense of agency lessened.

In Experiment 1, there was a significant main effect of actions. The time estimate for the voluntary action (self-initiative) was significantly shorter than the time estimate for the involuntary actions (following instruction). The main effect of outcome was not significant. The estimates for self-interest, altruism, and neutral outcomes were similar. However, there was a significant interaction between involuntary action and outcome. It was estimated that altruistic and neutral outcomes would take longer than self-interest outcomes, meaning self-interest outcomes would have a stronger SoA. In Experiment 2, there was a main effect of actions. The SoA was weaker in the involuntary action. The main effect of the outcome was significant. The time interval estimation of self-interest and altruistic outcomes was longer than that of neutral outcomes. There was less SoA in self-interest and altruistic outcomes, and there was no significant difference between the two outcomes. No significant interaction was found.

The results of our study show that voluntary action plays a significant role in the process of SoA. Individual agency is primarily determined by voluntary action and the nature of outcomes. Involuntary action can reduce individual agency. Predictability can change the individual’s perception of the outcomes, especially when the self-interest outcome is more predictable than the altruistic outcome. The agency of self-interest and altruistic outcomes had no difference under unpredictable conditions and was weaker than the neutral outcome. The results show that outcome (self-interest and altruism) has a top-down effect on SoA and the effect is more prominent in voluntary action.

Key words: sense of agency, voluntary action, nature of outcomes, predictability, temporal binding effect