A causal role for the right Angular Gyrus in Self-Location mediated Perspective Taking

This dataset is part of an original research paper published on 23 December, 2020 in Scientific Reports. It was conducted by international PhD student Debbie M.L. de Boer at the QUT Institute of Health and Biomedical Innovation (IHBI) from April 26th until July 1st 2019. It investigated whether the brain’s ability to locate itself might be the key mechanism for self-identification and distinguishing self from other signals (i.e. perspective-taking).

Experimental Design

This study comprised a fully randomised, double-blind and sham-controlled high definition tDCS experiment. The experiment had a crossover, mixed factorial design with two repeated measures (i.e., sessions) on the dependent variables and one independent grouping factor with four levels (i.e., experimental conditions). In each session, healthy volunteers controlled for susceptibility factors (e.g., time Perceptual Aberration Scale, t-PAS) completed a (i) stereoscopic 3D Full-body Illusion (FBI) paradigm and (ii) a (control) Perspective Taking (PT) computer task. Half of the participants received active stimulation on Session 1 versus sham stimulation on Session 2. The FBI-paradigm had two dependent variables: (i) the pre- and posttest displacement scores (behavioral measure with two levels) and (ii) the total exit-interview scores (psychometric measure). The PT-task (composed of an OBT-task & control LAT-task) had four dependent variables with three levels: (i) mean response times and (ii) accuracy scores were calculated for each of three blocks per task. OBT = own-body transformation; LAT = lateralisation.

Statistical Analyses

The experiment had six dependent variables spread over two tasks (FBI; PT) with two repeated measures (Session 1 & 2) and one grouping variable (i.e., four experimental conditions). Each of the dependent variables (e.g., “Total Exit Interview Score”) was analyzed separately in a mixed ANOVA with one between-subjects factor (e.g., “Experimental Condition” with four levels) and one within-subjects factor (e.g., “Session” with two levels). Where appropriate, the four experimental groups were taken together creating an independent variable “Stimulation Order” with two levels: stimulation Session 1 (FBI-PT 1 & PT-FBI 1) versus stimulation Session 2 (FBI-PT 2 & PT-FBI 2). In addition, the dependent variables of the PT-task were analyzed in a one-way repeated measures MANOVA to check for task-learning effects over consecutive blocks and sessions irrespective of stimulation order. Finally, correlations between behavioural and psychometric measures (incl. a reliability check) are reported.

本数据集隶属于2020年12月23日发表于《Scientific Reports》（《科学报告》）的原创研究论文。本研究由昆士兰科技大学（QUT）健康与生物医学创新研究所（IHBI）的国际博士生Debbie M.L. de Boer于2019年4月26日至7月1日开展，旨在探究大脑的自我定位能力是否是实现自我识别以及区分自我与他人信号（即观点采择（perspective-taking））的核心机制。

实验设计
本实验为完全随机、双盲且安慰剂对照的高清经颅直流电刺激（high definition tDCS）实验，采用交叉混合析因设计：因变量设置2次重复测量（即两次测试时段），分组自变量包含4个水平（即4种实验条件）。在每个测试时段中，已对易感因素（如时间知觉异常量表（time Perceptual Aberration Scale, t-PAS））进行控制的健康志愿者需完成两项任务：(i) 立体3D全身错觉（Full-body Illusion, FBI）范式任务，以及(ii) （对照）观点采择（Perspective Taking, PT）计算机任务。半数受试者在第1测试时段接受活性刺激，而在第2测试时段接受安慰剂刺激。
全身错觉范式任务包含两项因变量：(i) 测验前与测验后的位移得分（分为两个水平的行为学指标），以及(ii) 终末访谈总得分（心理测量学指标）。观点采择任务由自体转换（own-body transformation, OBT）任务与对照偏侧化（lateralisation, LAT）任务组成，共包含四项各分为3个水平的因变量：针对每项任务的三个试次块分别计算(i) 平均反应时与(ii) 正确率得分。

统计分析
本实验共包含六项因变量，分布于两项任务（全身错觉范式FBI、观点采择任务PT）中，且设置了两次重复测量（第1、2测试时段）与一项分组变量（即4种实验条件）。每项因变量（如"终末访谈总得分"）均采用混合方差分析（mixed ANOVA）单独进行分析，该分析包含一个被试间因素（如包含4个水平的"实验条件"）与一个被试内因素（如包含2个水平的"测试时段"）。在适宜条件下，将4个实验组合并为一个名为"刺激顺序"的自变量，其包含两个水平：第1测试时段接受刺激（FBI-PT 1与PT-FBI 1）与第2测试时段接受刺激（FBI-PT 2与PT-FBI 2）。
此外，针对观点采择任务的因变量采用单因素重复测量多元方差分析（one-way repeated measures MANOVA）进行分析，以检验不受刺激顺序影响的、连续试次块与测试时段间的任务学习效应。最后，本研究报告了行为学指标与心理测量学指标间的相关性（包括信度检验）。