Simulation models of facial expressions suggest that posterior visual areas and brain areas underpinning sensorimotor simulations might interact to improve facial expression processing. According to these models, facial mimicry, a manifestation of sensorimotor simulation, may contribute to the visual processing of facial expressions by influencing early stages. The aim of this study was to assess whether and how sensorimotor simulation influences early stages of face processing, also investigating its relationship with alexithymic traits given that previous studies have suggested that individuals with high levels of alexithymic traits (vs. individuals with low levels of alexithymic traits) tend to use sensorimotor simulation to a lesser extent. We monitored P1 and N170 ERP components of the event-related potentials (ERP) in participants performing a fine discrimination task of facial expressions and animals, as a control condition. In half of the experiment, participants could freely use their facial mimicry whereas in the other half they had their facial mimicry blocked by a gel. Our results revealed that only individuals with lower compared to high alexithymic traits showed a larger modulation of the P1 amplitude as a function of the mimicry manipulation selectively for facial expressions (but not for animals), while we did not observe any modulation of the N170. Given the null results at the behavioural level, we interpreted the P1 modulation as compensative visual processing in individuals with low levels of alexithymia under conditions of interference on the sensorimotor processing, providing a preliminary evidence in favor of sensorimotor simulation models.

面部表情的仿真模型表明，支撑感觉运动模拟的后视觉区域和大脑区域可能会相互作用以改善面部表情处理。根据这些模型，模仿面部表情（感觉运动模拟的一种表现）可能会通过影响早期阶段来促进面部表情的视觉处理。这项研究的目的是评估感觉运动模拟是否以及如何影响面部加工的早期阶段，并研究其与失神症特征的关系，因为先前的研究表明，个体具有较高的失神症特征（相对于失神症水平低的个体）特质）倾向于在较小程度上使用感觉运动模拟。我们监控了执行面部表情和动物的精细区分任务的参与者的事件相关电位（ERP）的P1和N​​170 ERP组件，以此作为控制条件。在实验的一半中，参与者可以自由使用面部模仿，而在另一半中，他们的面部模仿被凝胶阻塞。我们的研究结果表明，只有具有较低的失神症特征的人才能表现出较大的P1振幅调节，这是模仿面部表情的模拟操作的函数（而非动物），而我们没有观察到N170的任何调节。鉴于在行为水平上没有结果，我们将P1调制解释为在感觉运动处理受到干扰的情况下，具有低水平的运动障碍的个体的补偿性视觉处理，