1 Institute of Cognitive Neuroscience, University College London.
2 Department of Psychology, University of Bologna.
Psychol Sci. 2017 Jul;28(7):882-893. doi: 10.1177/0956797617697693. Epub 2017 May 10.
Sense of agency-a feeling of control over one's actions and their outcomes-might include at least two components: free choice over which outcome to pursue and motoric control over the action causing the outcome. We orthogonally manipulated locus of outcome choice (free or instructed choice) and motoric control (active or passive movement), while measuring the perceived temporal attraction between actions and outcomes ( temporal binding) as an implicit marker of agency. Participants also rated stimulus intensity so that we could measure sensory attenuation, another possible implicit marker of agency. Actions caused higher or lower levels of either painful heat or mild electrotactile stimulation. We found that both motoric control and outcome choice contributed to outcome binding. Moreover, free choice, relative to instructed choice, attenuated the perceived magnitude of high-intensity outcomes, but only when participants made an active movement. Thus, choosing, not just doing, influences temporal binding and sensory attenuation, though in different ways. Our results show that these implicit measures of agency are sensitive to both voluntary motor commands and instrumental control over action outcomes.
主体感——对自身行为及其结果的控制感——可能包含至少两个成分：对追求哪种结果的自由选择，以及对导致结果的行为的运动控制。我们正交地操纵结果选择（自由或指令选择）和运动控制（主动或被动运动），同时测量行为和结果之间的感知时间吸引力（时间绑定），作为主体感的一个隐含标记。参与者还对刺激强度进行了评分，以便我们可以测量感觉衰减，这也是主体感的另一个可能的隐含标记。动作导致更高或更低水平的疼痛热或温和的电触觉刺激。我们发现，运动控制和结果选择都对结果绑定有贡献。此外，与指令选择相比，自由选择会减弱对高强度结果的感知程度，但前提是参与者进行主动运动。因此，选择，而不仅仅是行动，会影响时间绑定和感觉衰减，尽管方式不同。我们的结果表明，这些主体感的隐含测量对自愿运动指令和对动作结果的工具控制都很敏感。
