Sepulveda Francisco, Dyson Matthew, Gan John Q, Tsui C L
BCI Group, Dept. of Computer Science, University of Essex, United Kingdom.
Annu Int Conf IEEE Eng Med Biol Soc. 2007;2007:5055-8. doi: 10.1109/IEMBS.2007.4353476.
Aiming at developing asynchronous BCIs, we tested 21 2-class combinations of 7 mental tasks to determine whether any pair of tasks may be more suitable. The tasks under consideration were: auditory recall, mental navigation, sensorimotor attention (left hand), sensorimotor attention (right hand), mental calculation, imaginary movement (left hand), imaginary movement (right hand). Sensorimotor attention is novel in this application domain. All possible pairs were tried in 5 subjects using data from 10s periods in which subjects were free to execute the required mental task at their own pace. Recordings were done whilst the subject controlled a robot navigation simulator on a computer monitor, with the robot direction being related to the mental task. Classification of the data was done using LDA. Class-separation was estimated using the Davies-Bouldin index. Best classification results were obtained when auditory recall was followed or preceded by mental calculation. Of the possible 21 task combinations, this task pair was in the top 5 (performance-wise) for 4 of the 5 subjects. This was also the case when class-separation was used as a criterion.
为了开发异步脑机接口，我们测试了7种心理任务的21种二分类组合，以确定是否有任何一对任务可能更合适。所考虑的任务有：听觉回忆、心理导航、感觉运动注意（左手）、感觉运动注意（右手）、心算、想象运动（左手）、想象运动（右手）。感觉运动注意在这个应用领域是新颖的。使用来自10秒时间段的数据，在5名受试者中尝试了所有可能的组合，在此期间受试者可以自由地按照自己的节奏执行所需的心理任务。记录是在受试者控制计算机显示器上的机器人导航模拟器时进行的，机器人的方向与心理任务相关。使用线性判别分析（LDA）对数据进行分类。使用戴维斯-布尔丁指数估计类分离。当听觉回忆在进行心算之前或之后时，获得了最佳分类结果。在可能的21种任务组合中，对于5名受试者中的4名，这一任务对在（性能方面）排名前5。当使用类分离作为标准时，情况也是如此。
