Neurophysiology Lab, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy; Cognition in Action (CIA) Unit - PHILAB, Department of Philosophy, Università degli Studi di Milano, Milano, Italy.
Neurophysiology Lab, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy.
Cortex. 2022 Jun;151:224-239. doi: 10.1016/j.cortex.2022.03.007. Epub 2022 Mar 29.
When acting together, we may represent not only our own individual goals but also a collective goal. Although behavioural evidence suggests that agents' motor plans might be related to collective goals, direct neurophysiological evidence of whether collective goals are motorically represented is still scarce. The aim of the present transcranial magnetic stimulation (TMS) study is to begin to fill this gap. A participant and a confederate were asked to sequentially perform a two-choice reaction time task by acting on pressure sensors. In their own turn, they saw a cue indicating whether to lift their fingers from (or to press them on) a pressure sensor to shoot a ball across the screen as fast as possible. The confederate responded with the right hand, the participant with the left hand. While the confederate acted on the sensor, the participant's motor evoked potentials (MEPs) were collected from the right Extensor Carpi Ulnaris. If participants represent their own and the confederate's actions as being directed to a collective goal, MEPs amplitude should be modulated according to the action the confederate should perform. To test this conjecture, we contrasted three conditions: a Joint condition, in which both players worked together with their collective goal being to shoot the ball to get it to a common target, a Parallel condition, in which the players performed exactly the same task but received independent outcomes for their performance, and a Competitive condition, in which the outcome of the game still depended on the other player performance, but without the collective goal feature. Results showed no MEPs modulation according to the confederate's action in the Joint condition. Post-hoc exploratory analyses both provide some hints about this negative finding and also suggest possible improvements (i.e., adopting a different dependent variable, avoiding task-switching between conditions) for testing our hypothesis that collective goal can be represented motorically.
当共同行动时，我们不仅可以代表自己的个体目标，还可以代表集体目标。尽管行为证据表明，代理人的运动计划可能与集体目标有关，但关于集体目标是否在运动上得到体现的直接神经生理学证据仍然很少。本研究旨在使用经颅磁刺激（TMS）技术开始填补这一空白。要求一名参与者和一名同伙通过按压压力传感器来依次执行二择一反应时任务。在轮到他们时，他们会看到一个提示，指示他们是要抬起手指（或按压手指）离开压力传感器，以便尽快将球射过屏幕。同伙用右手，参与者用左手做出反应。当同伙在传感器上操作时，从参与者的右尺侧腕伸肌（Extensor Carpi Ulnaris）中收集运动诱发电位（MEPs）。如果参与者将自己和同伙的动作表示为指向集体目标，则 MEPs 的幅度应根据同伙应执行的动作进行调制。为了检验这一假设，我们对比了三种条件：联合条件，在该条件下，两名参与者共同合作，他们的集体目标是将球射向共同目标；平行条件，在该条件下，两名参与者执行完全相同的任务，但他们的表现有独立的结果；竞争条件，在该条件下，游戏的结果仍然取决于另一名参与者的表现，但没有集体目标的特征。结果显示，在联合条件下，MEPs 没有根据同伙的动作进行调制。事后探索性分析既提供了一些关于这一否定发现的线索，也为我们的假设提供了一些可能的改进建议（即采用不同的因变量，避免在条件之间切换任务），以检验我们的假设，即集体目标可以在运动上得到体现。
