Reducing alertness does not affect line bisection bias in neurotypical participants

This is a set of .csv data files as well as R analysis code for the project stated in the title. Participants were required to bisect 32 horizontal lines of varying size and shape (see McIntosh et al., 2005; 2017) on a computer screen using their mouse. This was done with and without spatial cues (shortly displayed, red, vertical lines at one end of the horizontal line), followed by a vigilance task, followed by the line bisection task again. The vigilance task was a 50-minute task in which a horizontal line moved up and down randomly; whenever it reached a certain threshold (i.e., it crossed a static horizontal line in the top half of the screen), participants were meant to push the space bar as quickly as possible. On average, participants' reaction times decreased over the vigilance task, suggesting a reduction in alertness. Similarly, for about half the sample this reduction was also indicated by the Stanford Sleepiness Scale. For the other half of the sample, no such data could be used, as the Stanford Sleepiness Scale was translated incorrectly. While the reduction in alertness did not have an effect on a measure of spatial attention (endpoint weightings bias, EWB), it did show an effect on a measure of general attention, endpoint weightings sum (EWS). McInt_Vig_04-20.csv and McInt_Vig_cue_04-20.csv contain, for each participant, all bisection measures derived without cues and with cues, respectively. McInt_Vig_vig.csv contains the reaction times of participants to the vigilance task. Edit: Added raw data本数据集包含对应标题所述研究项目的.csv格式数据文件与R语言分析代码。实验要求参与者通过鼠标在电脑屏幕上平分32条尺寸、形状各异的水平线（参考McIntosh等人2005、2017年研究）。实验流程为：参与者首先执行两组水平线平分任务——一组带有空间线索（spatial cues，即短暂呈现的红色垂直线，位于水平线一端），另一组无此类线索；随后完成警戒任务，最后再次执行水平线平分任务。警戒任务时长为50分钟，任务中一条水平线会随机上下移动，当该线越过屏幕上半区域的静态水平线阈值时，参与者需尽快按下空格键。平均而言，参与者在警戒任务中的反应时随任务推进逐渐缩短，提示警觉性下降。类似地，约半数样本的斯坦福嗜睡量表（Stanford Sleepiness Scale）结果也印证了这一警觉性下降趋势；而其余半数样本因斯坦福嗜睡量表翻译错误，无法使用对应数据。警觉性下降并未对空间注意指标——端点权重偏差（endpoint weightings bias, EWB）产生显著影响，但对一般注意指标——端点权重总和（endpoint weightings sum, EWS）存在显著作用。McInt_Vig_04-20.csv与McInt_Vig_cue_04-20.csv分别存储了每位参与者在无线索与有线索条件下得到的所有平分任务指标；McInt_Vig_vig.csv则存储了参与者在警戒任务中的反应时数据。编辑说明：本次更新新增了原始数据。