Like the back of my hand

Experimental stimuli, code and electrophysiological data. Please refer to the ReadMe file for further information about the files. Paradigm description In a first EEG experiment (discoverysample), event-related potentials (ERPs) were elicited by a pair of sequentially presented visual stimuli (vS1 and vS2; duration of stimuli: 300ms; interstimulus: 1000ms), 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. Experiment 1 consisted of two different scenarios (i.e. With Self and Without Self); in the With Self scenario, visual stimuli included participants’ self-hand. Four different types of pairs were presented: Self-Self (with both vS1 and vS2depicting the self-hand); Other1-Other1 (with vS1 and vS2 depicting the same hand belonging to a stranger – Other1); Self-Other1 (with vS1 representing the self-hand and vS2 Other1’s hand); Other1-Self (with vS1 representing Other1’s hand and vS2 the self-hand). In the WithoutSelf scenario, the self-hand was never presented. Four different types of pairs were delivered: Other2-Other2 (withvS1 and vS2 depicting the same hand belonging to a stranger – Other2, different from Other1); Other3-Other3 (with both vS1 and vS2 depicting the same hand belonging to a stranger – Other3, different from Other1and Other2); Other2-Other3 (with vS1 representing Other2’s hand and vS2 Other3’shand); Other3-Other2 (with vS1representing Other3’s hand and vS2 Other2’s hand).In Experiment 2, we included a third scenario, i.e. the With Familiar scenario. In this scenario, we presented two others’ hands. Importantly, one of these hands was familiar for the participant (i.e. the Familiar hand), since it had already been repeatedly presented in the immediately preceding scenario (which, depending on the specific sequence assigned to subject, might either be the With Self or the Without Self scenario). Four different pair types were presented: Familiar-Familiar (with both vS1 and vS2 depicting the familiarized hand); Other4-Other4 (with vS1 and vS2 depicting the same hand belonging to a stranger – Other4); Familiar-Other4 (with vS1 representing the familiarized hand and vS2 Other4’s hand); Other4-Familiar (with vS1 representing Other4’s hand and vS2 the familiarized hand).

本数据集包含实验刺激材料、代码与电生理数据，有关文件的详细信息请参阅ReadMe文档。

### 实验范式说明
在首次脑电实验（发现样本组）中，成对依次呈现的视觉刺激（vS1与vS2，刺激时长300ms，刺激间隔1000ms）可诱发事件相关电位（event-related potentials, ERPs），刺激类型为被试自身手部或他人手部图像。
在第二次脑电实验（重复样本组）中，除上述视觉刺激外，还增设了熟悉手部刺激。实验要求被试判断vS2与vS1是否完全一致，并记录其反应正确率与反应时。

实验1包含两种情境："有自我"与"无自我"情境。
在"有自我"情境中，视觉刺激包含被试自身手部，共四类刺激对：
1. 自我-自我（Self-Self）：vS1与vS2均呈现被试自身手部；
2. 他人1-他人1（Other1-Other1）：vS1与vS2均呈现同一陌生人的手部（记为Other1）；
3. 自我-他人1（Self-Other1）：vS1为被试自身手部，vS2为Other1的手部；
4. 他人1-自我（Other1-Self）：vS1为Other1的手部，vS2为被试自身手部。

在"无自我"情境中，不呈现被试自身手部，共四类刺激对：
1. 他人2-他人2（Other2-Other2）：vS1与vS2均呈现同一陌生人的手部（记为Other2，与Other1不同）；
2. 他人3-他人3（Other3-Other3）：vS1与vS2均呈现同一陌生人的手部（记为Other3，与Other1、Other2均不同）；
3. 他人2-他人3（Other2-Other3）：vS1为Other2的手部，vS2为Other3的手部；
4. 他人3-他人2（Other3-Other2）：vS1为Other3的手部，vS2为Other2的手部。

实验2新增第三种情境："有熟悉手"情境。该情境中呈现两名他人的手部，其中一种为被试熟悉的手部（记为熟悉手），该手部已在前一紧邻情境中被反复呈现（根据被试分配的具体序列，前一情境可为"有自我"或"无自我"情境）。共四类刺激对：
1. 熟悉手-熟悉手（Familiar-Familiar）：vS1与vS2均呈现该熟悉手部；
2. 他人4-他人4（Other4-Other4）：vS1与vS2均呈现同一陌生人的手部（记为Other4）；
3. 熟悉手-他人4（Familiar-Other4）：vS1为熟悉手部，vS2为Other4的手部；
4. 他人4-熟悉手（Other4-Familiar）：vS1为Other4的手部，vS2为该熟悉手部。