Galigani Mattia, Ronga Irene, Fossataro Carlotta, Bruno Valentina, Castellani Nicolò, Rossi Sebastiano Alice, Forster Bettina, Garbarini Francesca
Manibus Lab, Psychology Department, University of Turin, Turin, Italy.
Manibus Lab, Psychology Department, University of Turin, Turin, Italy.
Cortex. 2021 Jan;134:239-252. doi: 10.1016/j.cortex.2020.10.014. Epub 2020 Nov 13.
The ability to identify our own body is considered a pivotal marker of self-awareness. Previous research demonstrated that subjects are more efficient in the recognition of images representing self rather than others' body effectors (self-advantage). Here, we verified whether, at an electrophysiological level, bodily-self recognition modulates change detection responses. In a first EEG experiment (discovery sample), event-related potentials (ERPs) were elicited by a pair of sequentially presented visual stimuli (vS1; vS2), representing either the self-hand or other people's hands. In a second EEG experiment (replicating sample), together with the previously described visual stimuli, also a familiar hand was presented. Participants were asked to decide whether vS2 was identical or different from vS1. Accuracy and response times were collected. In both experiments, results confirmed the presence of the self-advantage: participants responded faster and more accurately when the self-hand was presented. ERP results paralleled behavioral findings. Anytime the self-hand was presented, we observed significant change detection responses, with a larger N270 component for vS2 different rather than identical to vS1. Conversely, when the self-hand was not included, and even in response to the familiar hand in Experiment 2, we did not find any significant modulation of the change detection responses. Overall our findings, showing behavioral self-advantage and the selective modulation of N270 for the self-hand, support the existence of a specific mechanism devoted to bodily-self recognition, likely relying on the multimodal (visual and sensorimotor) dimension of the bodily-self representation. We propose that such a multimodal self-representation may activate the salience network, boosting change detection effects specifically for the self-hand.
识别自身身体的能力被视为自我意识的关键标志。先前的研究表明，与识别他人身体效应器的图像相比，受试者在识别代表自身的图像时效率更高（自我优势）。在此，我们验证了在电生理水平上，身体自我识别是否会调节变化检测反应。在第一个脑电图实验（发现样本）中，一对依次呈现的视觉刺激（vS1；vS2）诱发了事件相关电位（ERP），这些刺激分别代表自己的手或他人的手。在第二个脑电图实验（重复样本）中，除了上述视觉刺激外，还呈现了一只熟悉的手。参与者被要求判断vS2与vS1是否相同。收集了准确率和反应时间。在两个实验中，结果都证实了自我优势的存在：当呈现自己的手时，参与者的反应更快且更准确。ERP结果与行为学发现一致。每当呈现自己的手时，我们都观察到显著的变化检测反应，当vS2与vS1不同而非相同时，N270成分更大。相反，当不包括自己的手时，甚至在实验2中对熟悉的手做出反应时，我们都没有发现变化检测反应有任何显著的调节。总体而言，我们的研究结果表明了行为上的自我优势以及对自己的手的N270的选择性调节，支持了存在一种专门用于身体自我识别的特定机制，这可能依赖于身体自我表征的多模态（视觉和感觉运动）维度。我们提出，这种多模态自我表征可能会激活突显网络，从而专门增强对自己的手的变化检测效果。
