BCI Competition 2008–Graz data set A

This data set consists of EEG data from 9 subjects. The cue-based BCI paradigm consisted of four di erent motor imagery tasks, namely the imag ination of movement of the left hand (class 1), right hand (class 2), both feet (class 3), and tongue (class 4). Two sessions on di erent days were recorded for each subject. Each session is comprised of 6 runs separated by short breaks. One run consists of 48 trials (12 for each of the four possible classes), yielding a total of 288 trials per session.At the beginning of each session, a recording of approximately 5 minutes was performed to estimate the EOG inuence. The recording was divided into 3 blocks: (1) two minutes with eyes open (looking at a xation cross on the screen), (2) one minute with eyes closed, and (3) one minute with eye movements. Note that due to technical problems the EOG block is shorter for subject A04T and contains only the eye movement condition.The subjects were sitting in a comfortable armchair in front of a com puter screen. At the beginning of a trial (t = 0s), a xation cross appeared on the black screen. In addition, a short acoustic warning tone was pre sented. After two seconds (t = 2s), a cue in the form of an arrow pointing either to the left, right, down or up (corresponding to one of the four classesleft hand, right hand, foot or tongue) appeared and stayed on the screen for 1.25s. This prompted the subjects to perform the desired motor imagery task. No feedback was provided. The subjects were ask to carry out the motor imagery task until the xation cross disappeared from the screen at t = 6s. A short break followed where the screen was black again.

本数据集包含9名受试者的脑电（Electroencephalogram, EEG）数据。该基于线索的脑机接口（Brain-Computer Interface, BCI）范式包含四种不同的运动想象任务，分别为左手运动想象（类别1）、右手运动想象（类别2）、双脚运动想象（类别3）以及舌头运动想象（类别4）。每名受试者在不同日期完成两次测试会话。每个测试会话包含6个运行段，段间设有短暂休息。每个运行段包含48个试次，四类任务各12个，因此每个测试会话总计288个试次。在每个测试会话开始前，会进行约5分钟的记录以评估眼电（Electrooculogram, EOG）干扰。该记录分为3个区块：(1) 双眼睁开状态2分钟（受试者注视屏幕上的固定十字），(2) 双眼闭合状态1分钟，(3) 眼球运动状态1分钟。需注意，由于技术故障，受试者A04T的眼电记录区块时长更短，仅包含眼球运动条件。受试者坐在舒适的扶手椅上，前方为电脑屏幕。每个试次开始时（t=0s），黑屏上会出现固定十字，同时播放一段短促的声学警示音。2秒后（t=2s），屏幕上会出现指向左、右、下、上的箭头提示线索（分别对应四类任务：左手、右手、双脚、舌头），该提示会持续显示1.25秒，以此提示受试者执行对应的运动想象任务，全程无反馈。受试者需持续进行运动想象，直至t=6s时固定十字从屏幕消失。随后会有一段短暂休息，屏幕再次变为黑屏。